OpenGL Support for Lightroom Classic CC on Mac

OpenGL Support for Lightroom Classic CC on Mac

lrclassic marquee 1440x660 900x413 OpenGL Support for Lightroom Classic CC on Mac

Okay, so I’ve been ‘banging on’ about the problem that quite a few people have been suffering from with the new Lightroom Classic CC and GPU acceleration since Adobe launched the new application.

I must stress that this problem does NOT seem to effect anyone using MBP or iMac, or indeed any Mac Pro that runs a factory-fitted GPU.  But if you can remember, I fitted my Mac Pro with an nVidia GTX 970 4Gb GPU a while back – mainly to help Photoshop CC with the heavy lifting in ‘Refine Edge’ and other masking/channel masking procedures.

But I’m now pleased to report that the problem is FIXED – and, as I suspected, the fix is simple, and the ‘fix’ is a tiny 28 byte file.  Yes, that’s right, 28 BYTES!

It’s an API Thing

Now I’m totally rubbish with computer jargon, but API is the acronym for Application Programming Interface, and with regard to GPU/Graphics Cards there a 4 main APIs:

  • OpenGL
  • Direct Ex – in other words Microsoft
  • Metal – in other words Apple
  • Vulcan – don’t ask/no idea

For some reason, on certain Mac systems, Lightroom Classic CC is not finding OpenGL, and is instead being forced into trying to use the OSX API ‘metal’.

The forums have been rife with Lightroom Classic CC problems for the last few days – this one included.  On one of these forums, Adobes Simon Chen, had been attempting to field questions over this problem.

I asked Simon if there was any way to ‘force’ Lightroom Classic CC to ignore the OSX API and default to OpenGL – which was obviously there on the system, because the previous iteration of Lightroom had been using it quite happily.

Simon suggested the installation of this tiny 28 byte ‘config.lua’ file into Lightrooms’ Application Support root folder – and would you believe it, it works!

You can download the config.lua file from here.

Below is a short video I’ve made this morning on how to download and install this tiny file which will re-instate Lightroom Classic CCs ability to use the OpenGL API.

So now I’m a happy bunny; and if you have the problem then just follow the video instructions and you’ll be a happy bunny too!

Big thanks to Simon Chen, Principle Scientist at Adobe for helping sort this irritating niggle out.

Adobe Lightroom Classic and Photoshop CC 2018 tips

Adobe Lightroom Classic and Photoshop CC 2018 tips – part 1

So, you’ve either upgraded to Lightroom Classic CC and Photoshop CC 2018, or you are thinking doing so.

Well, here are a couple of things I’ve found – I’ve called this part1, because I’m sure there will be other problems/irritations!

Lightroom Classic CC GPU Acceleration problem

If you are having problems with shadow areas appearing too dark and somewhat ‘chocked’ in the develop module – but things look fine in the Library module – then just follow the simple steps in the video above and TURN OFF GPU Acceleration in the Lightroom preferences panel under the performance tab.

Screen Shot 2017 10 19 at 12.06.49 1 900x506 Adobe Lightroom Classic and Photoshop CC 2018 tips

Turn OFF GPU Acceleration

UPDATE: I have subsequently done another video on this topic that illustrates the fact that the problem did not exist in Lr CC 2015 v.12/Camera Raw v.9.12

In the new Photoshop CC 2018 there is an irritation/annoyance with the brush tool, and something called the ‘brush leash’.

Now why on earth you need your brush on a leash God ONLY KNOWS!

But the brush leash manifests itself as a purple/magenta line that follows your brush tool everywhere.

You have a smoothness slider for your brush – it’s default setting is 10%.  If we increase that value then the leash line gets even longer, and even more bloody irritating.

And why we would need an indicator (which is what the leash is) of smoothness amount and direction for our brush strokes is a bit beyond me – because we can see it anyway.

So, if you want to change the leash length, use the smoothing slider.

If you want to change the leash colour just go to Photoshop>Preferences>Cursors

Screen Shot 2017 10 19 at 12.23.50 900x704 Adobe Lightroom Classic and Photoshop CC 2018 tips

Here, you can change the colour, or better still, get rid of it completely by unticking the “show brush leash while smoothing” option.

So there are a couple of tips from my first 24 hours with the latest 2018 ransom ware versions from Adobe!

But I’m sure there will be more, so stay tuned, and consider heading over to my YouTube channel and hitting the subscribe button, and hit the ‘notifications bell’ while you’re at it!

 

 

Monitors & Color Bit Depth

Monitors and Color Bit Depth – yawn, yawn – Andy’s being boring again!

Well, perhaps I am, but I know ‘stuff’ you don’t – and I’m telling YOU that you need to know it if you want to get the best out of your photography – so there!

Let me begin by saying that NOTHING monitor-related has any effect on your captured images.  But  EVERYTHING monitor-related DOES have an effect on the way you SEE your images, and therefore definitely has an effect on your image adjustments and post-processing.

So anything monitor-related can have either a positive or negative effect on your final image output.

Bit Depth

I’m going to begin with a somewhat disconnected analogy, but bare with me here.

We live in the ‘real and natural world’, and everything that we see around us is ANALOGUE.  Nature exists on a natural curve and is full of infinite variation. In the digital world though, everything has to be put in a box.

We’ll begin with two dogs – a Labrador and a Poodle.  In this instance both natural  and digital worlds can cope with the situation, because nature just regards them for what they are, and digital can put the Labrador in a box named ‘Labrador’ and the Poodle in a separate box just for Poodles.

Let’s now imagine for a fleeting second that Mr. Lab and Miss Poodle ‘get jiggy’ with the result of dog number 3 – a Labradoodle.  Nature just copes with the new dog because it sits on natures ‘doggy curve’ half way between Mum and Dad.

But digital is having a bloody hissy-fit in the corner because it can’t work out what damn box to put the new dog in.  The only way we can placate digital is to give it another box, one for 50% Labrador and 50% Poodle.

Now if our Labradoodle grows up a bit then starts dating and makes out with another Labrador then we end up with a fourth dog that is 75% Labrador and 25% Poodle.  Again, nature just takes all in her stride, but digital in now having a stroke because it’s got no box for that gene mix.

Every time we give digital a new box we have effectively given it a greater bit depth.

Now imagine this process of cross-breed gene dilution continues until the glorious day arrives when a puppy is born that is 99% Labrador and only 1% Poodle.  It’ll be obvious to you that by this time digital has a flaming warehouse full of boxes that can cope with just about any gene mix, but alas, the last time bit depth was increased was to accommodate 98% Lab 2% Poodle.

Digital is by now quite old and grumpy and just can’t be arsed anymore, so instead of filling in triplicate forms to request a bit depth upgrade it just lumps our new dog in the same classification box as the previous one.

So our new dog is put in the wrong box.

Digital hasn’t been slap-dash though and put the pup in any old box, oh no.  Digital has put the pup in the nearest suitable box – the box with the closest match to reality.

Please note that the above mentioned boxes are strictly metaphorical, and no puppies were harmed during the making of this analogy.

Digital images are made up of pixels, and a pixel can be thought of as a data point.  That single data point contains information about luminance and colour.  The precision of that information is determined by the bit depth of the data

Very little in our ‘real world’ has a surface that looks flat and uniform.  Even a supposedly flat, uniform white wall on a building has subtle variations and graduations of colour and brightness/luminance caused by the angular direction of light and its own surface texture. That’s nature for you in the analogy above.

We are all familiar with RGB values for white being 255,255,255 and black being 0,0,0, but those are only 8 bit values.

8 bit allows for 256 discrete levels of information (or gene mix classification boxes for our Labradoodles), and a scale from 0 to 255 contains 256 values – think about it for a second!

At all bit depth values black is always 0,0,0 but white is another matter entirely:

8 bit = 256 discrete values so image white is 255,255,255

10 bit = 1,024 discrete values so image white is 1023,1023,1023

12 bit = 4,096 discrete values so image white is 4095,4095,4095

14 bit = 16,384 discrete values so image white is 16383,16383,16383

15 bit = 32,768 discrete values so image white is 32767,32767,32767

16 bit = 65,536 discrete values so image white should be 65535,65535,65535 – but it isn’t – more later!

And just for giggles here are some higher bit depth potentials:

24 bit = 16,777,216 discrete values

28 bit = 268,435,456 discrete values

32 bit = 4,294,967,296 discrete values

So you can see a pattern here.  If we double the bit depth we square the value of the information, and if we halve the bit depth the information we are left with is the square root of what we started with.

And if we convert to a lower or smaller bit depth “digital has fewer boxes to put the different dogs in to, so Labradoodles of varying genetic make-ups end up in the same boxes.  They are no longer sorted in such a precise manner”.

The same applies to our images. Where we had two adjacent pixels of slightly differing value in 16 bit, those same two adjacent pixels can very easily become totally identical if we do an 8 bit conversion and so we lose fidelity of colour variation and hence definition.

This is why we should archive our processed images as 16 bit TIFFS instead of 8 bit JPEGs!

In an 8 bit image we have black 0,0,0 and white 255,255,255 and ONLY 254 available shades or tones to graduate from one to the other.

%name Monitors & Color Bit Depth

Whereas, in a 16 bit image black is 0,0,0 and white is 65535,65535,65535 with 65,534 intervening shades of grey to make the same black to white transition:

Gradient Monitors & Color Bit Depth

But we have to remember that whatever the bit depth value is, it applies to all 3 colour channels:

red Monitors & Color Bit Depth green Monitors & Color Bit Depth blue Monitors & Color Bit Depth

So a 16 bit image should contain a potential of 65536 values per colour channel.

How Many Colours?

So how many colours can our bit depth describe Andy?

Simple answer is to cube the bit depth value, so:

8 bit = 256x256x256 = 16,777,216 often quoted as 16.7 million colours.

10 bit = 1024x1024x1024 = 1,073,741,824 or 1.07 billion colours or EXACTLY 64x the value of 8 bit!

16 bit = 65536x65536x65536 = 281,474,976,710,656 colours. Or does it?

Confusion Reigns Supreme

Now here’s where folks get confused.

Photoshop does not WORK  in 16 bit, but in 15 bit + 1 level.  Don’t believe me? Go New Document, RGB, 16 bit and select white as the background colour.

Open up your info panel, stick your cursor anywhere in the image area and look at the 16 bit RGB read out and you will see a value of 32768 for all 3 colour channels – that’s 15 bit folks! Now double the 32768 value – yup, that’s right, you get 16 bit or 65,536!

Why does Photoshop do this?  Simple answer is ‘for speed’ – or so they say at Adobe!  There are numerous others reasons that you’ll find on various forums etc – signed and unsigned integers, mid-points, float-points etc – but really, do we care?

Things are what they are, and rumor has it that once you hit the save button on a 16 bit TIFF is does actually save out at 16 bit.

So how many potential colours in 16 bit Photoshop?  Dunno! But it’ll be somewhere between 35,184,372,088,832 and 281,474,976,710,656, and to be honest either value is plenty enough for me!

The second line of confusion usually comes from PC users under Windows, and the  Windows 24 bit High Color and 32 bit True Color that a lot of PC users mistakenly think mean something they SERIOUSLY DO NOT!

Windows 24 bit means 24 bit TOTAL – in short, 8 bits per channel, not 24!

Windows 32 bit True Color is something else again. Correctly known as 32 bit RGBA it contains 4 channels of 8 bits each; three 8 bit colour channels and an 8 bit Alpha channel used for transparency.

The same 32 bit RGBA colour (Mac call it ARGB) has been utilised on Mac OS for ever, but most Mac users never questioned it because it’s not quite so obvious in OSX as it is in Windows unless you look at the Graphics/Displays section of your System report, and who the Hell ever goes there apart from twats like me:

MacElCap8bit Monitors & Color Bit Depth

Above you can see the pixel depth being reported as 32 bit colour ARGB8888 – that’s Apple-speak for Windows 32 bit True Colour RGBA.  But like a lot of ‘things Mac’ the numbers give you the real information.  The channels are ordered Alpha, Red, Green, Blue and the four ‘8’s give you the bit depth of each pixel, or as Apple put it ‘pixel depth’.

However, in the latter part of 2015 Apple gave OSX 10.11 El Capitan a 10 bit colour capability, though hardly anyone knew including ‘yours truly’.  I never have understood why they kept it ‘on the down-low’ but there was no fan-fare that’s for sure.

MacElCap10bit Monitors & Color Bit Depth

Now you can see the pixel depth being reported as 30 bit ARGB2101010 – meaning that the transparency Alpha channel has been reduced from 8 bit to 2 bit and the freed-up 6 bits have been distributed evenly between the Red, Green and Blue colour channels.

Monitor Display

Your computer has a maximum display bit depth output capability that is defined by:

  • a. the operating system
  • b. the GPU fitted

Your system might well support 10 bit colour, but will only output 8 bit if the GPU is limited to 8 bit.

Likewise, you could be running a 10 bit GPU but if your OS only supports 8 bit, then 8 bit is all you will get out of the system (that’s if the OS will support the GPU in the first place).

Monitors have their own panel display bit depth, and panel bit depth costs money.

A lot of LCD panels on the market are only capable of displaying 8 bit, even if you run an OS and GPU that output 10 bit colour.

And then again certain monitors such as Eizo ColorEdge, NEC MultiSynch and the odd BenQ for example, are capable of displaying 10 bit colour from a 10 bit OS/GPU combo, but only if the monitor-to-system connection has 10 bit capability.  This basically means Display Port or HDMI connection.

As photographers we really should be looking to maximise our visual capabilities by viewing the maximum number of colour graduations captured by our cameras.  This means operating with the greatest available colour bit depth on a properly calibrated monitor.

Just to reiterate the fundamental difference between 8 bit and 10 bit monitor display pixel depth:

  • 8 bit = 256x256x256 = 16,777,216 often quoted as 16.7 million colours.
  • 10 bit = 1024x1024x1024 = 1,073,741,824 or 1.07 billion colours.

So 10 bit colour allows us to see exactly 64 times more colour on our display than 8 bit colour. (please note the word ‘see’).

It certainly does NOT add a whole new spectrum of colour to what we see; nor does it ‘add’ anything physical to our files.  It’s purely a ‘visual’ improvement that allows us to see MORE of what we ALREADY have.

I’ve made a pound or two from my images over the years and I’ve been happily using 8 bit colour right up until I bought my Eizo the other month, even though my system has been 10 bit capable since I upgraded the graphics card back in August last year.

The main reason for the upgrade with NOT 10 bit capability either, but for the 4Gb of ‘heavy lifting power’ for Photoshop.

But once I splashed the cash on a 10 bit display I of course made instant use of the systems 10 bit capability and all its benefits – of which there’s really only one!

The Benefits

The ability to see 64 times more colour means that I can see 64x more subtle variantions of the same colours I could see before.

With my wildlife images I find very little benefit if I’m honest, but with landscapes – especially sunset and twilight shots – it’s a different story.  Sunset and twighlight images have massive graduations of similar hues.  Quite often an 8 bit display will not be able to display every colour variant in a graduation and so will replace it with its nearest neighbor that it can display – (putting the 99% Lab pup in the 98% Lab box!).

This leads to a visual ‘banding’ on the display:

band Monitors & Color Bit Depth

The banding in the shot above is greatly exaggerated but you get the idea.

A 10 bit colour display also helps me to soft proof slightly faster for print too, and for the same reason.  I can now see much more subtle shifts in proofing when making the same tiny adjustments as I made when using 8 bit.  It doesn’t bring me to a different place, but it allows me to get there faster.

For me the switch to 10 bit colour hasn’t really improved my product, but it has increased my productivity.

If you can’t afford a 10 bit display then don’t stress as 8 bit ARGB has served me well for years!

But if you are still needing a new monitor display the PLEASE be careful what you are buying, as some displays are not even true 8 bit.

A good place to research your next monitor (if not taking the Eizo, NEC 10 bit route) is TFT Central

If you select the panel size you fancy and then look at the Colour Depth column you will see the bit depth values for the display.

You should also check the Tech column and only consider H-IPS panel tech.

Beware of 10 bit panels that are listed as 8 bit + FRC, and 8 bit panels listed as 6 bit + FRC.

FRC is the acronym for FRAME RATE CONTROL – also known as Temporal Dithering.  In very simple terms FRC involves making the pixels flash different colours at you at a frame rate faster than your eye can see.  Therefore you are fooled into seeing what is to all intents and purposes an out ‘n out lie.

It’s a tech that’s okay for gamers and watching movies, but certainly not for any form of colour management or photography workflow.

Do not entertain the idea of anything that isn’t an IPS, H-IPS or other IPS derivative.  IPS is the acronym for In Plane Switching technology.  This the the type of panel that doesn’t visually change if you move your head when looking at it!

So there we go, that’s been a bit of a ramble hasn’t it, but I hope now that you all understand bit depth and how it relates to a monitors display colour.  And let’s not forget that you are all up to speed on Labradoodles!

Color Temperature

Lightroom Color Temperature (or Colour Temperature if you spell correctly!)

“Andy – why the heck is Lightrooms temperature slider the wrong way around?”

That’s a question that I used to get asked quite a lot, and it’s started again since I mentioned it in passing a couple of posts ago.

The short answer is “IT ISN”T….it’s just you who doesn’t understand what it is and how it functions”.

But in order to give the definitive answer I feel the need to get back to basics though – so here goes.

The Spectrum Locus

Let’s get one thing straight from the start – LOCUS is just a posh word for PATH!

Visible light is just part of the electro-magnetic energy spectrum typically between 380nm (nanometers) and 700nm:

%name Color Temperature

In the first image below is what’s known as the Spectrum Locus – as defined by the CIE (Commission Internationale de l´Eclairage or International Commission on Illumination).

In a nutshell the locus represents the range of colors visible to the human eye – or I should say chromaticities:

1200px CIE1931xy blank Color Temperature

The blue numbers around the locus are simply the nanometer values from that same horizontal scale above. The reasoning behind the unit values of the x and y axis are complex and irrelevant to us in this post, otherwise it’ll go on for ages.

The human eye is a fickle thing.

It will always perceive, say, 255 green as being lighter than 255 red or 255 blue, and 255 blue as being the darkest of the three.  And the same applies to any value of the three primaries, as long as all three are the same.

perception Color Temperature

This stems from the fact that the human eye has around twice the response to green light as it does red or blue – crazy but true.  And that’s why your camera sensor – if it’s a Bayer type – has twice the number of green photosites on it as red or blue.

In rather over-simplified terms the CIE set a standard by which all colors in the visible spectrum could be expressed in terms of ‘chromaticity’ and ‘brightness’.

Brightness can be thought of as a grey ramp from black to white.

Any color space is a 3 dimensional shape with 3 axes x, y and z.

Z is the grey ramp from black to white, and the shape is then defined by the colour positions in terms of their chromaticity on the x and y axes, and their brightness on the z axis:

adobeRGB1998 Color Temperature

But if we just take the chromaticity values of all the colours visible to the human eye we end up with the CIE1931 spectrum locus – a two dimensional plot if you like, of the ‘perceived’ color space of human vision.

Now here’s where the confusion begins for the majority of ‘uneducated photographers’ – and I mean that in the nicest possible way, it’s not a dig!

Below is the same spectrum locus with an addition:

PlanckianLocus Color Temperature

This additional TcK curve is called the Planckian Locus, or dark body locus.  Now please don’t give up here folks, after all you’ve got this far, but it’ll get worse before it gets better!

The Planckian Locus simply represents the color temperature in degrees Kelvin of the colour emitted by a ‘dark body’ – think lump of pure carbon – as it is heated.  Its color temperature begins to visibly rise as its thermal temperature rises.

Up to a certain thermal temperature it’ll stay visibly black, then it will begin to glow a deep red.  Warm it up some more and the red color temperature turns to orange, then yellow and finally it will be what we can call ‘white hot’.

So the Planckian Locus is the 2D chromaticity plot of the colours emitted by a dark body as it is heated.

Here’s point of confusion number 1: do NOT jump to the conclusion that this is in any way a greyscale. “Well it starts off BLACK and ends up WHITE” – I’ve come across dozens of folk who think that – as they say, a little knowledge is a dangerous thing indeed!

What the Planckian Locus IS indicative of though is WHITE POINT.

Our commonly used colour management white points of D65, D55 and D50 all lie along the Planckian Locus, as do all the other CIE standard illumimant types of which there’s more than few.

The standard monitor calibration white point of D65 is actually 6500 Kelvin – it’s a standardized classification for ‘mean Noon Daylight’, and can be found on the Spectrum Locus/Plankckian Locus at 0.31271x, 0.32902y.

D55 or 5500 Kelvin is classed as Mid Morning/Mid Afternoon Daylight and can be found at 0.33242x, 0.34743y.

D50 or 5000 kelvin is classed as Horizon Light with co-ordinates of 0.34567x, 0.35850.

But we can also equate Planckian Locus values to our ‘picture taking’ in the form of white balance.

FACT: The HIGHER the color temperature the BLUER the light, and lower color temperatures shift from blue to yellow, then orange (studio type L photofloods 3200K), then more red (standard incandescent bulb 2400K) down to candle flame at around 1850K).  Sunset and sunrise are typically standardized at 1850K and LPS Sodium street lights can be as low as 1700K.

And a clear polar sky can be upwards of 27,000K – now there’s blue for you!

And here’s where we find confusion point number 2!

Take a look at this shot taken through a Lee Big Stopper:

2 Color Temperature

I’m an idle git and always have my camera set to a white balance of Cloudy B1, and here I’m shooting through a filter that notoriously adds a pretty severe bluish cast to an image anyway.

If you look at the TEMP and TINT sliders you will see Cloudy B1 is interpreted by Lightroom as 5550 Kelvin and a tint of +5 – that’s why the notation is ‘AS SHOT’.

Officially a Cloudy white balance is anywhere between 6000 Kelvin and 10,000 kelvin depending on your definition, and I’ve stuck extra blue in there with the Cloudy B1 setting, which will make the effective temperature go up even higher.

So either way, you can see that Lightrooms idea of 5550 Kelvin is somewhat ‘OFF’ to say the least, but it’s irrelevant at this juncture.

Where the real confusion sets in is shown in the image below:

1 Color Temperature

“Andy, now you’ve de-blued the shot why is the TEMP slider value saying 8387 Kelvin ? Surely it should be showing a value LOWER than 5550K – after all, tungsten is warm and 3200K”….

How right you are…..and wrong at the same time!

What Lightroom is saying is that I’ve added YELLOW to the tune of 8387-5550 or 2837.

FACT – the color temperature controls in Lightroom DO NOT work by adjusting the Planckian or black body temperature of light in our image.  They are used to COMPENSATE for the recorded Planckian/black body temperature.

If you load in image in the develop module of Lightroom and use any of the preset values, the value itself is ball park correct(ish).

The Daylight preset loads values of 5500K and +10. The Shade preset will jump to 7500K and +10, and Tungsten will drop to 2850K and +/-0.

But the Tungsten preset puts the TEMP slider in the BLUE part of the slider Blue/Yellow graduated scale, and the Shade preset puts the slider in the YELLOW side of the scale, thus leading millions of people into mistakenly thinking that 7500K is warmer/yellower than 2850K when it most definitely is NOT!

This kind of self-induced bad learning leaves people wide open to all sorts of misunderstandings when it comes to other aspects of color theory and color management.

My advice has always been the same, just ignore the numbers in Lightroom and do your adjustments subjectively – do what looks right!

But for heaven sake don’t try and build an understanding of color temperature based on the color balance control values in Lightroom – otherwise you get in one heck of a mess.

Monitor Calibration Update

Monitor Calibration Update

Okay, so I no longer NEED a new monitor, because I’ve got one – and my wallet is in Leighton Hospital Intensive Care Unit on the critical list..

What have you gone for Andy?  Well if you remember, in my last post I was undecided between 24″ and 27″, Eizo or BenQ.  But I was favoring the Eizo CS2420, on the grounds of cost, both in terms of monitor and calibration tool options.

But I got offered a sweet deal on a factory-fresh Eizo CS270 by John Willis at Calumet – so I got my desire for more screen real-estate fulfilled, while keeping the costs down by not having to buy a new calibrator.

%name Monitor Calibration Update

But it still hurt to pay for it!

Monitor Calibration

There are a few things to consider when it comes to monitor calibration, and they are mainly due to the physical attributes of the monitor itself.

In my previous post I did mention one of them – the most important one – the back light type.

CCFL and WCCFL – cold cathode fluorescent lamps, or LED.

CCFL & WCCFL (wide CCFL) used to be the common type of back light, but they are now less common, being replaced by LED for added colour reproduction, improved signal response time and reduced power consumption.  Wide CCFL gave a noticeably greater colour reproduction range and slightly warmer colour temperature than CCFL – and my old monitor was fitted with WCCFL back lighting, hence I used to be able to do my monitor calibration to near 98% of AdobeRGB.

CCFL back lights have one major property – that of being ‘cool’ in colour, and LEDs commonly exhibit a slightly ‘warmer’ colour temperature.

But there’s LEDs – and there’s LEDs, and some are cooler than others, some are of fixed output and others are of a variable output.

The colour temperature of the backlighting gives the monitor a ‘native white point’.

The ‘brightness’ of the backlight is really the only true variable on a standard type of LCD display, and the inter-relationship between backlight brightness and colour temperature, and the size of the monitors CLUT (colour look-up table) can have a massive effect on the total number of colours that the monitor can display.

Industry-standard documentation by folk a lot cleverer than me has for years recommended the same calibration target settings as I have alluded to in previous blog posts:

White Point: D65 or 6500K

Brightness: 120 cdm² or candelas per square meter

Gamma: 2.2

Screen Shot 2017 04 02 at 13.04.25 Monitor Calibration Update

The ubiquitous ColorMunki Photo ‘standard monitor calibration’ method setup screen.

This setup for ‘standard monitor calibration’ works extremely well, and has stood me in good stead for more years than I care to add up.

As I mentioned in my previous post, standard monitor calibration refers to a standard method of calibration, which can be thought of as ‘software calibration’, and I have done many print workshops where I have used this method to calibrate Eizo ColorEdge and NEC Spectraviews with great effect.

However, these more specialised colour management monitors have the added bonus of giving you a ‘hardware monitor calbration’ option.

To carry out a hardware monitor calibration on my new CS270 ColorEdge – or indeed any ColorEdge – we need to employ the Eizo ColorNavigator.

The start screen for ColorNavigator shows us some interesting items:

colnav1 Monitor Calibration Update

The recommended brightness value is 100 cdm² – not 120.

The recommended white point is D55 not D65.

Thank God the gamma value is the same!

Once the monitor calibration profile has been done we get a result screen of the physical profile:

colnav2 Monitor Calibration Update

Now before anyone gets their knickers in a knot over the brightness value discrepancy there’s a couple of things to bare in mind:

  1. This value is always slightly arbitrary and very much dependent on working/viewing conditions.  The working environment should be somewhere between 32 and 64 lux or cdm² ambient – think Bat Cave!  The ratio of ambient to monitor output should always remain at between 32:75/80 and 64:120/140 (ish) – in other words between 1:2 and 1:3 – see earlier post here.
  2. The difference between 100 and 120 cdm² is less than 1/4 stop in camera Ev terms – so not a lot.

What struck me as odd though was the white point setting of D55 or 5500K – that’s 1000K warmer than I’m used to. (yes- warmer – don’t let that temp slider in Lightroom cloud your thinking!).

1000k Monitor Calibration UpdateAfter all, 1000k is a noticeable variation – unlike the brightness 20cdm² shift.

Here’s the funny thing though; if I ‘software calibrate’ the CS270 using the ColorMunki software with the spectro plugged into the Mac instead of the monitor, I visually get the same result using D65/120cdm² as I do ‘hardware calibrating’ at D55 and 100cdm².

The same that is, until I look at the colour spaces of the two generated ICC profiles:

profile Monitor Calibration Update

The coloured section is the ‘software calibration’ colour space, and the wire frame the ‘hardware calibrated’ Eizo custom space – click the image to view larger in a separate window.

The hardware calibration profile is somewhat larger and has a slightly better black point performance – this will allow the viewer to SEE just that little bit more tonality in the deepest of shadows, and those perennially awkward colours that sit in the Blue, Cyan, Green region.

It’s therefore quite obvious that monitor calibration via the hardware/ColorNavigator method on Eizo monitors does buy you that extra bit of visual acuity, so if you own an Eizo ColorEdge then it is the way to go for sure.

Having said that, the differences are small-ish so it’s not really worth getting terrifically evangelical over it.

But if you have the monitor then you should have the calibrator, and if said calibrator is ‘on the list’ of those supported by ColorNavigator then it’s a bit of a JDI – just do it.

You can find the list of supported calibrators here.

Eizo and their ColorNavigator are basically making a very effective ‘mash up’ of the two ISO standards 3664 and 12646 which call for D65 and D50 white points respectively.

Why did I go CHEAP ?

Well, cheaper…..

Apart from the fact that I don’t like spending money – the stuff is so bloody hard to come by – I didn’t want the top end Eizo in either 27″ or 24″.

With the ‘top end’ ColorEdge monitors you are paying for some things that I at least, have little or no use for:

  • 3D CLUT – I’m a general sort of image maker who gets a bit ‘creative’ with my processing and printing.  If I was into graphics and accurate repro of Pantone and the like, or I specialised in archival work for the V & A say, then super-accurate colour reproduction would be critical.  The advantage of the 3D CLUT is that it allows a greater variety of SUBTLY different tones and hues to be SEEN and therefore it’s easier to VISUALLY check that they are maintained when shifting an image from one colour space to another – eg softproofing for print.  I’m a wildlife and landscape photographer – I don’t NEED that facility because I don’t work in a world that requires a stringent 100% colour accuracy.
  • Built-in Calibrator – I don’t need one ‘cos I’ve already got one!
  • Built-in Self-Correction Sensor – I don’t need one of those either!

So if your photography work is like mine, then it’s worth hunting out a ‘zero hours’ CS270 if you fancy the extra screen real-estate, and you want to spend less than if buying its replacement – the CS2730.  You won’t notice the extra 5 milliseconds slower response time, and the new CS2730 eats more power – but you do get a built-in carrying handle!

 

Your Monitor – All You Ever Wanted Know

Your Monitor – All You Ever Wanted Know, and the stuff you didn’t – but need to!

I need a new monitor, but am undecided which to buy.  I know exactly which one I’d go for if money was no object – the NEC Spectraview Reference 302, but money is a very big object in that I ain’t got any spare!

But spend it I’ll have to – your monitor is the window on to your images and so is just about THE most important tool in your photographic workflow.  I do wish people would realize/remember that!

Right now my decision is between 24″ and 27″, Eizo or BenQ.  The monitor that needs replacement due to backlight degradation is my trusty HP LP2475W – a wide gamut monitor that punched way above its original price weight, and if I could find a new one I’d buy it right now – it was THAT good.

Now I know more than most about the ‘numbers bit’ of photography, and this current dilemma made me think about how much potential for money-wasting this situation could be for those that don’t ‘understand the tech’ quite as much as I do.

So I thought I’d try and lay things out for you in a simple and straight forward blog post – so here goes.

The Imaging Display Chain

Image Capture:

Let’s take my landscape camera – the Nikon D800E.  It is a 36 megapixel DSLR set to record UNCOMPRESSED 14 bit Raw files.

The RAW image produced by this camera has a pixel dimension of 7360 x 4912 and a pixel area of 36,152,320 pixels.

The horizontal resolution of this beastly sensor is approximately 5200 pixels per inch, each pixel being 4.88 µm (microns) in diameter – that’s know as pixel pitch.

During the exposure, the ANALOGUE part of the senor sees the scene in full spectrum colour and tone through its Bayer Array – it gathers an analogue image.

When the shutter closes, the DIGITAL side of the imaging sensor then basically converts the analogue image into a digital render with a reproduction accuracy of 14 bits per pixel.

And let’s not forget the other big thing – colour space.  All dslr cameras capture their images in their very own unique sensor colour space.  This bares little to no resemblance to either of the three commonly used digital colour management workflow colour spaces of sRGB, AdobeRGB1998 or ProPhotoRGB.

But for the purposes of digital RAW workflow, RAW editors such as Lightroom do an exceptional job of conserving the majority if not all the colours captured by the camera sensor, by converting the capture colour space to that of ProPhotoRGB – basically because it’s by far the largest industry standard space with the greatest spread of HSL values.

So this RAW file that sits on my CF card, then gets ingested by my Mac Pro for later display on my monitor is:

  • 1.41 inches on its long edge
  • has a resolution of around 5,200 pixels per inch
  • has a reproduction accuracy for Hue, Saturation & Luminance of 14 bits
  • has a colour space unique to the camera, which can best be reproduced by the ProPhotoRGB working colour space.

Image Display:

Now comes the tricky bit!

In order to display an image on a monitor, said monitor has to be connected to your computer via your graphics card or GPU output. This creates a larger number of pitfalls and bear traps for the unsuspecting and naive!

Physical attributes of a monitor you need to bare in mind:

  1. Panel Display Colour Bit Depth
  2. Panel Technology – IPS etc
  3. Monitor Panel Backlight – CCFL, WCCFL, LED etc
  4. Monitor Colour Look-Up Table – Monitor On-Board LUT (if applicable)
  5. Monitor connectivity
  6. Reliance on dedicated calibration device or not

The other consideration is your graphics card Colour Look-Up Table – GPU LUT

1.Monitor Panel Display Colour Bit Depth – All display monitors have a panel display colour bit depth – 8 bit or 10 bit.

I had a client turn up here last year with his standard processing setup – an oldish Acer laptop and an Eizo Colour Edge monitor – he was very proud of this setup, and equally gutted at his stupidity when it was pointed out to him.

The Eizo was connected to the laptop via a DVI to VGA lead, so he had paid a lot of good money for a 10 bit display monitor which he was feeding via a connection that was barely 8 bit.

Sat next to the DVI input on the Eizo was a Display Port input – which is native 10 bit. A Display Port lead doesn’t cost very much at all and is therefore the ONLY sensible way to connect to a 10 bit display – provided of course that your machine HAS a Display Port output – which his Acer laptop did not!

So if you are looking at buying a new monitor make sure you buy one with a display bit depth that your computer is capable of supporting.

There is visually little difference between 10 bit and 8 bit displays until you view an image at 100% magnification or above – then you will usually see something of an increase in colour variation and tonal shading, provided that the image you are viewing has a bit depth of 10+.  The difference is often quoted at its theoretical value of 64x –  (1,073,741,824 divided by 16,777,216).

So, yes, your RAW files will LOOK and APPEAR slightly better on a 10 bit monitor – but WAIT!

There’s more….how does the monitor display panel achieve its 10 bit display depth?  Is it REAL or is it pseudo? Enter FRC or Frame rate Control.

The FRC spoof 10 bit display – frame rate control quite literally ‘flickers’ individual pixels between two different HSL values at a rate fast enough to be undetectable by the human eye – the viewers brain gets fooled into seeing an HSL value that isn’t really there!

04 9 Your Monitor   All You Ever Wanted Know

Here’s why I hate FRC !

Personally I have zero time for FRC technology in panels – I’d much prefer a good solid 8 bit wide gamut panel without it than a pseudo 10 bit; which is pretty much the same 8 bit panel with FRC tech and a higher price tag…Caveat Emptor!

2. Panel Technology – for photography there is only really one tech to use, that of IPS or In Plane Switching.  The main reasons for this are viewing angle and full colour gamut.

The more common monitors, and cheaper ones most often use TN tech – Twisted Nematic, and from a view angle point of view these are bloody awful because the display colour and contrast vary hugely with even just an inch or two head movement.

Gamers don’t like IPS panels because the response time is slow in comparison to TN – so don’t buy a gaming monitor for your photo work!

There are also Vertical Alignment (VA) and Plane to line Switching (PLS) technologies out there, VA being perhaps marginally better than TN, and PLS being close to (and in certain cases better than) IPS.

But all major colour work monitor manufacturers use IPS derivative tech.

3. Monitor Panel Backlight – CCFL, WCCFL, LED

All types of TFT (thin film transistor) monitor require a back light in order to view what is on the display.

Personally I like – or liked before it started to get knackered – the wide cold cathode fluorescent (WCCFL) backlight on the HP LP2475W, but these seem to have fallen by the wayside somewhat in favour of LED backlights.

The WCCFL backlight enabled me to wring 99% of the Adobe1998 RGB colourspace out of a plain 8 bit panel on the old HP, and it was a very even light across the whole of the monitor surface.  The monitor itself is nearly 11 years old, but it wasn’t until just over 12 months ago that it started to fade at the corners.  Only since the start of this year (2017) has it really begun to show signs of more severe failure on the right hand 20% – hence I’ll be needing a new one soonish!

But modern LED backlights have a greater degree of uniformity – hence their general supersedence of WCCFL.

4. Colour Look-Up Tables or LUTs

Now this is a bit of an awkward one for some folk to get their heads around, but really it’s simple.

Most monitors that you can buy have an 8 bit LUT which is either fixed, or variable via a number of presets available within the monitor OSD menu.

When it comes to calibrating a ‘standard gamut with fixed LUT’ monitor, the calibration software makes its alterations to the LUT of the GPU – not that of the monitor.

With monitors and GPUs that are barely 8 bit to begin with, the act of calibration can lead to problems.

A typical example would be an older laptop screen.  A laptop screen is driven by the on-board graphics component or chipset within the laptop motherboard.  Older MacBooks were the epitome of this setups failure for photographers.

The on-board graphics in older MacBooks were barely 8 bit from the Apple factory, and when you calibrated them they fell to something like 6 bit, and so a lot of images that contained varied tones of a similar Hue displayed colour banding:

1 Your Monitor   All You Ever Wanted Know

An example of image colour banding due to low GPU LUT bit depth.
The banding is NOT really there, it just illustrates the lack of available colours and tones for the monitor display.

This phenomenon used to be a pain in the bum when choosing images for a presentation, but was never anything to panic over because the banding is NOT in the image itself.

Now if I display this same RAW file in Lightroom on my newer calibrated 15″ Retina MacBook Pro I still see a tiny bit of banding, though it’s not nearly this bad.  However, if I connect an Eizo CS2420 using a DisplayPort to HDMI cable via the 10 bit HDMI port on the MBP then there is no banding at all.

And here’s where folk get confused – none of what we are talking about has a direct effect on your image – just on how it appears on the monitor.

When I record a particular shade of say green on my D800E the camera records that green in its own colour space with an accuracy of 14 bits per colour channel.  Lightroom will display it’s own interpretation of that colour green.  I will make adjustments to that green in HSL terms and then ask Lightroom to export the result as say a TIFF file with 16 bits of colour accuracy per channel – and all the time this is going on I’m viewing the process on a monitor which has a display colour bit depth of 8 bit or 10 bit and that is deriving its colour from a LUT which could be 8 bit, 14 bit or 16 bit depending on what make and model monitor I’m using!

Some people get into a state of major confusion when it comes to bits and bit depth, and to be honest there’s no need for it.  All we are talking about here is ‘fidelity of reproduction’ on the monitor of colours which are FIXED and UNALTERABLE in your RAW file, and of the visual impact of your processing adjustments.

The colours contained in our image are just numbers – nothing more than that.

Lightroom will display an image by sending colour numbers through the GPU LUT to the monitor.  I can guarantee you that even with the best monitor in the world in conjunction with the most accurate calibration hardware money can buy, SOME of those colour numbers will NOT display correctly!  They will be replaced in a ‘relative colourmetric manner’ by their nearest neighbor in the MONITOR LUT – the colours the monitor CAN display.

Expensive monitors with 14 bit or 16 bit LUTs mean less colours will be ‘replaced’ than when using a monitor that has an 8 bit LUT, and even more colours will be replaced if we scale back our ‘spend’ even further and purchase a standard gamut sRGB monitor.

Another advantage of the pricier 14/16 bit wide gamut dedicated photography monitors from the likes of Eizo, NEC and BenQ is the ability to do ‘hardware calibration’.

Whereas the ‘standard’ monitor calibration mentioned earlier makes it’s calibration changes primarily to the GPU LUT, and therefore somewhat ‘stiffles’ its output bit depth; with hardware calibration we can internally calibrate the monitor itself and leave the GPU running as intended.

That’s a slight over-simplification, but it makes the point!

5. Monitor Connectivity. By this I mean connection type:

74f97065a3 193829 belkin pcmonitor 606 original Your Monitor   All You Ever Wanted Know

VGA or D-Sub 15. Awful method of connection – went out with the Ark. If you are using this then “stop it”!

de98677f26 193829 dual linkdvi d original Your Monitor   All You Ever Wanted Know

DVI – nothing wrong with this connection format whatsoever, but bare in mind it’s an 8 bit connection.

12 189 047 08 Your Monitor   All You Ever Wanted Know

Dual Link DVI – still only 8 bit.

Display Port seitlich Your Monitor   All You Ever Wanted Know

Displayport – 10 bit monitor input connection.

578306 544748 800 Your Monitor   All You Ever Wanted Know

HDMI left, Displayport right – both 10 bit connections.

6. Reliance on dedicated calibration device or not – this is something that has me at the thin end of a sharp wedge if I consider the BenQ option.

I own a perfectly serviceable ColorMunki Photo, and as far as I can see, hardware calibration on the Eizo is feasible with this device. However, hardware calibration on BenQ system software does not appear to support the use of my ColorMunki Photo – so I need to purchase an i1 Display, which is not a corner I really want to be backed into!

Now remember how we defined my D800E Raw file earlier on:

  • has a pixel dimension of 7360 x 4912 and a pixel area (or resolution) of 36,152,320 pixels.
  • 1.41 inches on its long edge
  • has a resolution of around 5,200 pixels per inch
  • has a reproduction accuracy for Hue, Saturation & Luminance of 14 bits
  • has a colour space unique to the camera, which can best be reproduced by the ProPhotoRGB working colour space.

So let’s now take a look at the resolution spec for, say, the NEC Spectraview Reference 302 monitor.  It’s a 30″ panel with an optimum resolution of 2560 x 1600 pixels – that’s 4Mp!

The ubiquitous Eizo ColorEdge CG2420 has a standard 24 inch resolution of 1920 x 1200 pixels – that’s 2.3Mp!

The BenQ SW2700PT Pro 27in IPS has 2560 x 1440, or 3.68Mp resolution.

Yes, monitor resolution is WAY BELOW that of the image – and that’s a GOOD THING.

I HATE viewing unedited images/processing on my 13″ Retina MBP screen – not just because of any possible calibration issue, or indeed that of its diminutive size – but because of its whopping 2560 x 1600, 4Mp resolution crammed into such a small space.

The individual pixels are so damn tiny the lull you into a false sense of security about one thing above all else – critical image sharpness.

Images that ‘appear tack sharp’ on a high resolution monitor MIGHT prove a slight disappointment when viewed on another monitor with a more conventional resolution!

So there we have it, and I hope you’ve learned something you didn’t know about monitors.

And remember, understanding what you already have, and what you want to buy is a lot more advantageous to you than the advice of some bloke in a shop who’s on a sales commission!

If this post has been useful to you then please consider chucking me a small donation – or a big one if you are that way inclined!

Many thanks to the handful of readers who contributed over the last week or so – you’ve done your bit and I’m eternally grateful to you.

 

Lightroom – Neutralise Hidden Exposure Compensation

Lightroom – Neutralise Hidden Exposure Compensation.

We all know how good Lightroom is – but it’s also a total pain in the arse!

Ages ago, I did a post about Lightroom 5 and accurate colour HERE and, according to this blogs page-view stats, that post still gets a large global viewing figure every month – so it’s something of an on-going problem for a lot of users.

But things have moved on a bit since then, and we are now working with the v5 release of Lightroom 6/CC 2015 – and things haven’t got any better, sadly, from the perspective of actually “seeing what you captured”.

The problem lies in the fact that Lightroom, for a long time, ceased to be a “neutral” RAW handler.  It uses a variety of ‘behind the scenes’ algorithms to add what it thinks are good adjustments in terms of exposure brightness and contrast.  In other words Lightroom adds hidden adjustments which we cannot see because they are not registered on the adjustment sliders under process version 2012.

Why does it do this – God only knows!

But when I take into account the support Lightroom currently offers for mobile phone cameras, cloud synch etc, I can’t help thinking that Adobe are trying to give Lightroom some sort of mass-market appeal by adding what the designers and coders think is some sort of WOW-factor to image previews – though I might be wrong!

But whatever Adobes reasoning, the fact remains that SOME OF US want to see our raw files for what they are – straight gamma 2.2 encoded versions of what the sensor recorded.  Only by learning how to Neutralise Hidden Exposure Compensation  can we actually arrive at a suitable starting point for the development process.

The Case To Answer

Firstly, a lot of you might be wondering WTF I’m ranting on about – your RAW image previews look great before you start doing anything to them – mmmmm….

If that’s the case then NEWS FLASH – RAW files should look as flat as dish-water pre-process, and you have do some work to make them look good.  So believe me, if your raws look “nice ‘n punchy” from the get-go then something is wrong somewhere!

Out there in photography land there are two RAW file handlers that are notorious for being “neutral” in their initial raw render – Raw Digger, and Iridient Developer.

Let me demonstrate the “case to answer” by using the same image I used the other day when giving Canon an indirect slagging off over lossless compression:

FW1Q1351 2 600x400 Lightroom   Neutralise Hidden Exposure Compensation

Raw file opened in Lightroom with no user adjustments BUT WITH Lightroom ‘hidden exposure compensation’.

Now let’s open the same file in Raw Digger:

RawDigger Lightroom   Neutralise Hidden Exposure Compensation

Raw file opened in Raw Digger with no user adjustments.

And now in Iridient Developer:

IridientDev Lightroom   Neutralise Hidden Exposure Compensation

Raw file opened in Iridient Developer with no user adjustments.

And now, just for good measure, my Lightroom-processed version of the image:

FW1Q1351 600x400 Lightroom   Neutralise Hidden Exposure Compensation

Raw file processed in Lightroom WITH user adjustments.

Both RAW Digger and Iridient Developer give the user a much better processing start point simply because they are neutral and don’t go about making contrast-loaded ‘background adjustments’.  And I’m sure you can see that the final Lightroom processed version of the image bares more resemblance to the RAW Digger and Iridient screen grabs than the Lightroom ‘as is’ preview.

Now if you are a total maniac then you can go and download either of the two aforementioned raw developers and get yourself super-confused or you can learn how to ‘neutralise’ the Lightroom background adjustment ‘crap’ – which is far easier!

How to Neutralise Hidden Exposure Compensation in Lightroom.

Step 1.  Scroll down to the Camera Calibration Panel in the Develop module and switch the Process Version from PV2012 to PV 2010:

Step1 600x375 Lightroom   Neutralise Hidden Exposure Compensation

Step 1 in Neutralising Lightroom Hidden Exposure Compensation.

Step 2.  Scroll up to the Basics panel (a very different looking one if you never used Lightroom 3!) and make the following changes:

  1. Blacks from 5 to 0
  2. Brightness from +50 to 0
  3. Contrast from +25 to 0
Step 2 600x375 Lightroom   Neutralise Hidden Exposure Compensation

Step 2 in Neutralising Lightroom Hidden Exposure Compensation.

Step 3.  Move to the Tone Curve and change the Medium Contrast tone curve to Linear:

Step 3 600x375 Lightroom   Neutralise Hidden Exposure Compensation

Step 3 in Neutralising Lightroom Hidden Exposure Compensation.

DO NOT concern yourself with the fact that your image has gone dark and flat, it’s to be expected!

Step 4.  Scroll back down to Camera Calibration and switch the process version BACK to PV2012, then scroll back up to the Basics Panel:

Step 4 600x375 Lightroom   Neutralise Hidden Exposure Compensation

Step 4 in Neutralising Lightroom Hidden Exposure Compensation.

Step 5.  Yes I know it still looks awful, but if you now change that -1EV to 0 on the exposure slider you’ll get a great process start image:

Step 5 600x375 Lightroom   Neutralise Hidden Exposure Compensation

Step 5 in Neutralising Lightroom Hidden Exposure Compensation.

Looking at the before and after images you can see that we have got contrast under control – in other words we have removed the excess contrast added to the image with the  Lightroom hidden background shenanigans.

Indeed, we can see exactly how much contrast has been removed with this ‘by the numbers’ process by looking at the -33 Contrast value – DO NOT RESET THIS BACK TO 0!!!!

The process has decreased contrast still further by lifting the Blacks value to +25.  You need to check the shadow areas on the image in this respect.  If they are looking a bit noisy (Hello Canon!) you might want to drop the blacks value to maybe +5 to +10 and open the shadows a bit more with a small positive adjustment to the Shadows slider in the basics panel.

And so processing is just a matter of a few subjective tweaks until I’m happy with the image:

Final 600x375 Lightroom   Neutralise Hidden Exposure Compensation

Click to view larger image.

In the Tone Curve panel you can see the multi-point Custom Curve the process has added.  If you click the up/down arrows to the right of the word Custom you will see a menu giving you the option to save the curve:

SaveCurve Lightroom   Neutralise Hidden Exposure Compensation

Saving the custom curve.

I save the curve with the name 2010to2012 – by default it saves as an .xmp file, and to the user/Library/Application Support/Adobe/CameraRaw/Curves file path (Mac).

Saving the curve is useful as it makes for a very quick adjustment of further images.

However, there is a caveat (isn’t there always!) and it’s this:

The majority of  adjustments in Lightroom are specific to camera sensor and ISO.  In simple terms the same numeric value of adjustment to any control slider can have differing effects depending on the sensor it was made by and the ISO at which it was shot.  It’s very important that you wrap your head around this fact.

The curve I’ve produced here is correct for a Canon 1DX at the shot ISO which was 1000 or 800 if my memory serves correctly.  I could apply this curve to a 100 ISO image shot with a Nikon D800E, and it would do a good job, but I might get a slightly better result if I go through the whole process again to produce a custom curve for the D800E using a 100 ISO shot to begin with.  But even if that new curve visually gives a different result it will still have the same numeric values in the basics panel!

If I save the curve and then apply it to another image via the Tone Curve panel the contrast and blacks Basic Panel values do NOT change – but you will get a better distribution of contrast.

You may want to generate and save at least a low and high ISO variant of the curve for each of your camera bodies; or you could be a smart-arse like me by just using one curve and eye-balling the finer tweaks.

You can also create the curve and then save the settings as a User Develop Preset and then apply it to future imports via the import module.

So there you have it, how to Neutralise Hidden Exposure Compensation in Lightroom and see you images properly – have fun folks!

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Colour in Photoshop

Colour in Photoshop.

Understanding colour inside Photoshop is riddled with confusion for the majority of users.  This is due to the perpetual misuse of certain words and terms.  Adobe themselves use incorrect terminology – which doesn’t help!

The aim of this post is to understand the attributes or properties of colour inside the Photoshop environment – “…is that right Andy?”  “Yeh, it is!”

So, the first colour attribute we’re going to look at is HUE:

ColWheel1 1 Colour in Photoshop

A colour wheel showing point-sampled HUES (colours) at 30 degree increments.

HUE can be construed as meaning ‘colour’ – or color for the benefit of our American friends “come on guys, learn to spell – you’ve had long enough!”

The colour wheel begins at 0 degrees with pure Red (255,0,0 in 8bit RGB terms), and moves clockwise through all the HUES/colours to end up back at pure Red – simple!

Hue1 Colour in Photoshop

Above, we can see samples of primary red and secondary yellow together with their respective HUE degree values which are Red 0 degrees and Yellow 60 degrees.  You can also see that the colour channel values for Red are 255,0,0 and Yellow 255,255,0.  This shows that Yellow is a mix of Red light and Green light in equal proportions.

I told you it was easy!

Inside Photoshop the colour wheel starts and ends at 180 degrees CYAN, and is flattened out into a horizontal bar as in the Hue/Saturation adjustment:

ColWheel2 Colour in Photoshop

Overall, there is no ambiguity over the meaning or terminology HUE; it is what it is, and it is usually taken as meaning ‘what colour’ something is.

The same can be said for the next attribute of colour – SATURATION.

Or can it?

How do we define saturation?

Sat1 Colour in Photoshop

Two different SATURATION values (100% & 50%) of the same HUE.

Above we can see two different saturation values for the same HUE (0 degrees Hue, 100% and 50% Saturation). I suppose the burning question is, do we have two different ‘colours’?

As photographers we mainly work with additive colour; that is we add Red, Green and Blue coloured light to black in order to attain white.  But in the world of painting for instance, subtractive colour is used; pigments are overlaid on white (thus subtracting white) to make black.  Printing uses the same model – CMY+K inks overlaid on ‘white’ paper …..mmm see here

If we take a particular ‘colour’ of paint and we mix it with BLACK we have a different SHADE of the same colour.  If we instead add WHITE we end up with what’s called a TINT of the same colour; and if add grey to the original paint we arrive at a different TONE of the same colour.

Let’s look at that 50% saturated Red again:

Sat2 Colour in Photoshop

Hue Red 0 degrees with 50% saturation.

We’ve basically added 128 Green and 128 Blue to 255 Red. Have we kept the same HUE – yes we have.

Is it the same colour? Be honest – you don’t know do you!

The answer is NO – they are two different ‘colours’, and the hexadecimal codes prove it – those are the hash-tag values ff0000 and ff8080.  But in our world of additive colour we should only think of the word ‘colour’ as a generalisation because it is somewhat ambiguous and imprecise.

But we can quantify the SATURATION of a HUE – so we’re all good up to this point!

So we beaver away in Photoshop in the additive RGB colour mode, but what you might not realise is that we are working in a colour model within that mode, and quite frankly this is where the whole chebang turns to pooh for a lot of folk.

There are basically two colour models for dare I use the word ‘normal’, photography work; HSB (also known as HSV) and HSL, and both are cylindrical co-ordinate colour models:

HSBHSL Colour in Photoshop

HSB (HSV) and HSL colour models for additive RGB.

Without knowing one single thing about either, you can tell they are different just by looking at them.

All Photoshop default colour picker referencing is HSB – that is Hue, Saturation & Brightness; with equivalent RGB, Lab, CMYK  hexadecimal values:

col3 Colour in Photoshop

But in the Hue/Sat adjustment for example, we see the adjustments are HSL:

ColWheel2 Colour in Photoshop

The HSL model references colour in terms of Hue, Saturation & Lightness – not flaming LUMINOSITY as so many people wrongly think!

And it’s that word luminosity that’s the single largest purveyor of confusion and misunderstanding – luminosity masking, luminosity blending mode are both terms that I and oh so many others use – and we’re all wrong.

I have an excuse – I know everything, but I have to use the wrong terminology otherwise no one else knows what I’m talking about!!!!!!!!!  Plausible story and I’m sticking to it your honour………

Anyway, within Photoshop, HSB is used to select colours, and HSL is used to change them.

The reason for this is somewhat obvious when you take a close look at the two models again:

HSBHSL Colour in Photoshop

HSB (HSV) and HSL colour models for additive RGB. (V stands for Value = B in HSB).

In the HSB model look where the “whiteness” information is; it’s radial, and bound up in the ‘S’ saturation co-ordinate.  But the “blackness” information is vertical, on the ‘B’ brightness co-ordinate.  This great when we want to pick/select/reference a colour.

But surely it would be more beneficial for the “whiteness” and “blackness” information to be attached to the axis or dimension, especially when we need to increase or decrease that “white” or “black” co-ordinate value in processing.

So within the two models the ‘H’ hue co-ordinates are pretty much the same, but the ‘S’ saturation co-ordinates are different.

So this leaves us with that most perennial of questions – what is the difference between Brightness and Lightness?

Firstly, there is a massive visual difference between the Brightness and Lightness  information contained within an image as you will see now:

BHSB Colour in Photoshop

The ‘Brightness’ channel of HSB.

LHSL Colour in Photoshop

The ‘L’ channel of HSL

Straight off the bat you can see that there is far more “whites detail” information contained in the ‘L’ lightness map of the image than in the brightness map.  Couple that with the fact that Lightness controls both black and white values for every pixel in your image – and you should now be able to comprehend the difference between Lightness and Brightness, and so be better at understanding colour inside Photoshop.

We’ll always use the highly bastardised terms like luminosity, luminance etc – but please be aware that you may be using them to describe something to which they DO NOT APPLY.

Luminosity is a measure of the magnitude of a light source – typically stars; but could loosely be applied to the lumens output power of any light source.  Luminance is a measure of the reflected light from a subject being illuminated by a light source; and varies with distance from said light source – a la the inverse square law etc.

Either way, neither of them have got anything to do with the pixel values of an image inside Photoshop!

But LIGHTNESS certainly does.

Monitor Brightness.

Monitor Brightness & Room Lighting Levels.

I had promised myself I was going to do a video review of my latest purchase – the Lee SW150Mk2 system and Big and Little Stopper filters I’ve just spent a Kings ransom on for my Nikon 14-24mm and D800E:

D4D3598 Edit Monitor Brightness.

PURE SEX – and I’ve bloody well paid for this! My new Lee SW150 MkII filter system for the Nikon 14-24. Just look at those flashy red anodised parts – bound to make me a better photographer!

But I think that’ll have to wait while I address a question that keeps cropping up lately.  What’s the question?

Well, that’s the tricky bit because it comes in many guises. But they all boil down to “what monitor brightness or luminance level should I calibrate to?”

Monitor brightness is as critical as monitor colour when it comes to calibration.  If you look at previous articles on this blog you’ll see that I always quote the same calibration values, those being:

White Point: D65 – that figure takes care of colour.

Gamma: 2.2 – that value covers monitor contrast.

Luminance: 120 cdm2 (candelas per square meter) – that takes care of brightness.

Simple in’it….?!

However, when you’ve been around all this photography nonsense as long as I have you can overlook the possibility that people might not see things as being quite so blindingly obvious as you do.

And one of those ‘omissions on my part’ has been to do with monitor brightness settings COMBINED with working lighting levels in ‘the digital darkroom’.  So I suppose I’d better correct that failing on my part now.

What does a Monitor Profile Do for your image processing?

A correctly calibrated monitor and its .icc profile do a really simple but very mission-critical job.

If we open a new document in Photoshop and fill it with flat 255 white we need to see that it’s white.  If we hold an ND filter in front of our eye then the image won’t look white, it’ll look grey.

If we hold a blue filter in front of our eye the image will not look white – it’ll look blue.

That white image doesn’t exist ‘inside the monitor’ – it’s on our computer!  It only gets displayed on the monitor because of the graphics output device in our machine.

So, if you like, we’re on the outside looking in; and we are looking through a window on to our white image.  The colour and brightness level in our white image are correct on the inside of the system – our computer – but the viewing window or monitor might be too bright or too dark, and/or might be exhibiting a colour tint or cast.

Unless our monitor is a totally ‘clean window’ in terms of colour neutrality, then our image colour will not be displayed correctly.

And if the monitor is not running at the correct brightness then the colours and tones in our images will appear to be either too dark or too bright.  Please note the word ‘appear’…

Let’s get a bit fancy and make a greyscale in Photoshop:

Untitled 1 Monitor Brightness.

The dots represent Lab 50 to Lab 95 – the most valuable tonal range between midtone and highlight detail.

Look at the distance between Lab 50 & Lab 95 on the three greyscales above – the biggest ‘span’ is the correctly calibrated monitor.  In both the ‘too bright & contrasty’ and the ‘too dark low contrast’ calibration, that valuable tonal range is compressed.

In reality the colours and tones in, say an unprocessed RAW file on one of our hard drives, are what they are.  But if our monitor isn’t calibrated correctly, what we ‘see’ on our monitor IS NOT REALITY.

Reality is what we need – the colours and tones in our images need to be faithfully reproduced on our monitor.

And so basically a monitor profile ensures that we see our images correctly in terms of colour and brightness; it ensures that we look at our images through a clean window that displays 100% of the luminance being sent to it – not 95% and not 120% – and that all our primary colours are being displayed with 100% fidelity.

In a nutshell, on an uncalibrated monitor, an image might look like crap, when in reality it isn’t.  The shit really starts to fly when you start making adjustments in an uncalibrated workspace – what you see becomes even further removed from reality.

“My prints come out too dark Andy – why?”

Because your monitor is too bright – CALIBRATE it!

“My pics look great on my screen, but everyone on Nature Photographers Network keeps telling me they’ve got too much contrast and they need a levels adjustment.  One guy even reprocessed one – everyone thought his version was better, but frankly it looked like crap to me – why is this happening Andy?

“Because your monitor brightness is too low but your gamma is too high – CALIBRATE it!  If you want your images to look like mine then you’ve got to do ALL the things I do, not just some of ’em – do you think I do all this shit for fun??????????……………grrrrrrr….

But there’s a potential problem;  just because your monitor is calibrated to perfection, that does NOT mean that everything will be golden from this point on

Monitor Viewing Conditions

So we’re outside taking a picture on a bright sunny day, but we can’t see the image on the back of the camera because there’s too much daylight, and we have to dive under a coat with our camera to see what’s going on.

But if we review that same image on the camera in the dark then it looks epic.

Now you have all experienced that…….

The monitor on the back of your camera has a set brightness level – if we view the screen in a high level of ambient light the image looks pale, washed out and in a general state of ultra low contrast.  Turn the ambient light down and the image on the camera screen becomes more vivid and the contrast increases.

But the image hasn’t changed, and neither has the camera monitor.

What HAS changed is your PERCEPTION of the colour and luminance values contained within the image itself.

Now come on kids – join the dots will you!

It does not matter how well your monitor is calibrated, if your monitor viewing conditions are not within specification.

Just like with your camera monitor, if there is too much ambient light in your working environment then your precisely calibrated monitor brightness and gamma will fail to give you a correct visualization or ‘perception’ of your image.

And the problems don’t end there either; coloured walls and ceilings reflect that colour onto the surface of your monitor, as does that stupid luminous green shirt you’re wearing – yes, I can see you!  And if you are processing on an iMac then THAT problem just got 10 times worse because of the glossy screen!

Nope – bead-blasting your 27 inches of Apple goodness is not the answer!

Right, now comes the serious stuff, so READ, INGEST and ACT.

ISO Standard 3664:2009 is the puppy we need to work to (sort of) – you can actually go and purchase this publication HERE should you feel inclined to dump 138 CHF on 34 pages of light bedtime reading.

There are actually two ISO standards that are relevant to us as image makers; ISO 12646:2015(draft) being the other.

12646 pertains to digital image processing where screens are to be compared to prints side by side (that does not necessarily refer to ‘desktop printer prints from your Epson 3000’).

3664:2009 applies to digital image processing where screen output is INDEPENDENT of print output.

We work to this standard (for the most part) because we want to process for the web as well as for print.

If we employ a print work flow involving modern soft-proofing and otherwise keep within the bounds of 3664 then we’re pretty much on the dance-floor.

ISO 3664 sets out one or two interesting and highly critical working parameters:

Ambient Light White Point: D50 – that means that the colour temperature of the light in your editing/working environment should be 5000Kelvin (not your monitor) – and in particular this means the light FALLING ON TO YOUR MONITOR from within your room. So room décor has to be colour neutral as well as the light source.

Ambient Light Value in your Editing Area: 32 to 64 Lux or lower.  Now this is what shocks so many of you guys – lower than 32 lux is basically processing in the dark!

Ambient Light Glare Permissible: 0 – this means NO REFLECTIONS on your monitor and NO light from windows or other light sources falling directly on the monitor.

Monitor White Point – D65 (under 3664) and D50 (under 12646) – we go with D65.

Monitor Luminance – 75 to 100 cdm2 (under 3664) and 80 to 120 cdm2 (under 12646 – here we begin to deviate from 3664.

We appear to be dealing with mixed reference units, but 1 Lux = 1 cdm2 or 1 candela per square metre.

The way Monitor Brightness or Luminance relates to ambient light levels is perhaps a little counter-intuitive for some folk.  Basically the LOWER your editing area Lux value the LOWER your Monitor Brightness or luminance needs to be.

Now comes the point in the story where common sense gets mixed with experience, and the outcome can be proved by looking at displayed images and prints; aesthetics as opposed numbers.

Like all serious photographers I process my own images on a wide-gamut monitor, and I print on a wide-gamut printer.

Wide gamut monitors display pretty much 90% to100% of the AdobeRGB1998 colour space.

What we might refer to as Standard Gamut monitors display something a little larger than the sRGB colour space, which as we know is considerably smaller than AdobeRGB1998.

StandardGamutvsWideGamut Monitor Brightness.

Left is a standard gamut/sRGB monitor and right is a typical wide gamut/AdobeRGB1998 monitor – if you can call any NEC ‘typical’!

Find all the gory details about monitors on this great resource site – TFT Central.

At workshops I process on a 27 inch non-Retina iMac – this is to all intents and purposes a ‘standard gamut’ monitor.

I calibrate my monitors with a ColorMunki Photo – which is a spectrophotometer.  Spectro’s have a tendency to be slow, and slightly problematic in the very darkest tones and exhibit something of a low contrast reaction to ‘blacks’ below around Lab 6.3 (RGB 20,20,20).

If you own a ColorMunki Display or i1Dispaly you do NOT own a spectro, you own a colorimeter!  A very different beast in the way it works, but from a colour point of view they give the same results as a spectro of the same standard – plus, for the most part, they work faster.

However, from a monitor brightness standpoint, they differ from spectros in their slightly better response to those ultra-dark tones.

So from a spectrophotometer standpoint I prefer to calibrate to ISO 12646 standard of 120cdm2 and control my room lighting to around 35-40 Lux.

Just so that you understand just how ‘nit-picking’ these standards are, the difference between 80cdm2 and 120 cdm2 is just 1/2 or 1/3rd of a stop Ev in camera exposure terms, depending on which way you look at it!

However, to put this monitor brightness standard into context, my 27 inch iMac came from Apple running at 290 cdm2 – and cranked up fully it’ll thump out 340 cdm2.

Most stand-alone monitors you buy, especially those that fall under the ‘standard gamut’ banner, will all be running at massively high monitor brightness levels and will require some severe turning down in the calibration process.

You will find that most monitor tests and reviews are done with calibration to the same figures that I have quoted – D65, 120cdm2 and Gamma 2.2 – in fact this non-standard set up has become so damn common it is now ‘standard’ – despite what the ISO chaps may think.

Using these values, printing out of Lightroom for example, becomes a breeze when using printer profiles created to the ICC v2 standard as long as you ‘soft proof’ the image in a fit and proper manner – that means CAREFULLY, take your time.  The one slight shortcoming of the set up is that side by side print/monitor comparisons may look ever so slightly out of kilter because of the D65 monitor white point – 6,500K transmitted white point as opposed to a 5,000K reflective white point.  But a shielded print-viewer should bring all that back into balance if such a thing floats your boat.

But the BIG THING you need to take away from the rather long article is the LOW LUX VALUE of you editing/working area ambient illumination.

Both the ColorMunki Photo and i1Pro2 spectrophotometers will measure your ambient light, as will the ColorMunki Display and i1 Display colorimeters, to name but a few.

But if you measure your ambient light and find the device gives you a reading of more than 50-60 lux then DO NOT ask the device to profile for your ambient light; in fact I would not recommend doing this AT ALL, here’s why.

I have a main office light that is colour corrected to 5000K and it chucks out 127 Lux at the monitor.  If I select the ‘measure and calibrate to ambient’ option on the ColorMunki Photo it eventually tells me I need a monitor brightness or luminance of 80 cdm2 – the only problem is that it gives me the same figure if I drop the ambient lux value to 100.

Now that smells a tad fishy to me……..

So my advice to anyone is to remove the variables, calibrate to 120 cdm2 and work in a very subdued ambient condition of 35 to 40 Lux. I find it easier to control my low lux working ambient light levels than bugger about with over-complex calibration.

To put a final perspective on this figure there is an interesting page on the Apollo Energytech website which quotes lux levels that comply with the law for different work environments – don’t go to B&Q or Walmart to do a spot of processing, and we’re all going to end up doing hard time at Her Madges Pleasure –  law breakers that we are!

Please consider supporting this blog.

This blog really does need your support. All the information I put on these pages I do freely, but it does involve costs in both time and money.

If you find this post useful and informative please could you help by making a small donation – it would really help me out a lot – whatever you can afford would be gratefully received.

Your donation will help offset the costs of running this blog and so help me to bring you lots more useful and informative content.

Many thanks in advance.

 

Photoshop Save for Web

Save for Web in Photoshop CC 2015 – where the Chuff has it gone?

“Who’s moved my freakin’ cheese?”

Adobe have moved it……..

For years Photoshop has always offered the same ‘Save for Web’ or ‘Save for Web & Devices’ option and dialogue box:

SFW1 900x563 Photoshop Save for Web

The traditional route to the ‘Save for Web’ dialogue in all versions of Photoshop prior to CC 2015.

But Adobe have embarked on a cheese-moving exercise with CC 2015 and moved ‘save for web’ out of the traditional navigation pathway:

SFW2 900x563 Photoshop Save for Web

Adobe have ‘moved your cheese’ to here, though the dialogue and options are the same.

If we take a closer look at that new pathway:

SFW3 Photoshop Save for Web

…we see that wonderful Adobe term ‘Legacy’ – which secretly means crap, shite, old fashioned, out dated, sub standard and scheduled for abandonment and/or termination.

‘THEY’ don’t want you to use it!

I have no idea why they have done this, though there are plenty of excuses being posted by Adobe on the net.  But what is interesting is this page HERE and more to the point this small ‘after thought’:

SFW4 Photoshop Save for Web

That sounds really clever – especially the bit about ‘may be’……. let’s chuck colour management out the freakin’ window and be done!

So if we don’t use the ‘legacy’ option of save for web, let’s see what happens.  Here’s our image, in the ProPhotoRGB colour space open in Photoshop CC 2015:

SFW5 900x563 Photoshop Save for Web

So let’s try the Export>Quick Export as JPG option and bring the result back into Photoshop:

SFW6 900x563 Photoshop Save for Web

Straight away we can see that the jpg is NOT tagged with a colour space, but it looks fine inside the Photoshop CC 2105 work space:

SFW7 900x563 Photoshop Save for Web

“Perfect” – yay!…………NOT!

Let’s open in with an internet browser……

SFW8 900x563 Photoshop Save for Web

Whoopsy – doopsy…!  Looks like a severe colour management problem is happening somewhere……..but Adobe did tell us:

SFW4 Photoshop Save for Web

Might the Export Preferences help us:

SFW9 900x563 Photoshop Save for Web

In a word……..NO

Let’s try Export>Export As:

SFW10 900x563 Photoshop Save for Web

Oh Hell No!

If we open the original image in Photoshop CC 2015 in the ProPhotoRGB colour space and then go Edit>Convert to Profile and select sRGB; then select Export>Quick Export as JPG, the resulting image will look fine in a browser.  But it will still be ‘untagged’ with any colour space – which is never a good idea.

And if you’ve captioned and key worded the image then all that hard work is lost too.

So if you must make your web jpeg images via Photoshop you will only achieve a quick and accurate work flow by using the Save for Web (Legacy) option.  That way you’ll have a correctly ‘tagged’ and converted image complete with all your IPTC key words, caption and title.

Of course you could adopt the same work flow as me, and always export as jpeg out of Lightroom; thus avoiding this mess entirely.

I seriously don’t know what the devil Adobe are thinking of here, and doubtless there is or will be a work around for the problem, but whatever it is it’ll be more work for the photographer.

Adobe – if it ain’t broke then don’t fix it !!

 

Please consider supporting this blog.

This blog really does need your support. All the information I put on these pages I do freely, but it does involve costs in both time and money.

If you find this post useful and informative please could you help by making a small donation – it would really help me out a lot – whatever you can afford would be gratefully received.

Donations would help offset the costs of running this blog and so help me to bring you lots more useful and informative content.

Many thanks in advance.