Frank asked me last week about the Topaz JPEG to RAW AI plugin and if it was any good.
Well, my response after downloading the free trial and messing about with it is this – it’s CRAP!
All it does is create a DNG file or 16 bit TIFF (you pick) from an 8 bit jpeg.
Should you opt for DNG then the DNG is NOT a raw file, it’s just a DNG with 8 bits per channel worth of information rattling around inside it. And if you opt for 16 bit TIFF then you end up with and 8 bit jpeg sitting inside a 16 bit TIFF container.
For the love of God, how the hell does the marketing department at Topaz think they can get away with this total bullshit – Ai learning my arse………….!
Are they trying to make the inexperienced and unknowledgeable actually believe that this expensive bit of garbage can re-engineer 32,000+ bits per channel from a poxy 8 bits per channel?
If you believe that then all I’ll say is that ‘a fool and their money are easily parted’………
Click image to view LARGE in new window
Click the image above and it will open in a new window. We are looking at 200% magnification of an are of the original raw file (right), a full resolution jpeg created from that raw file (middle), and a shitty DNG created by this abomination from Topaz on the left.
Notice something about the Topaz image – it’s got more artifacts in it than the original jpeg (middle) because there has been some form of sharpening applied to it by the Topaz software – and yet there are NO controls for any application of sharpening in the Topaz UI.
Let’s take something different – a jpeg of a Clouded Ermine.
Click the image to see what the original jpeg looks like.
One of the most stunningly beautiful moths in the UK, this Clouded Ermine is resting on tree bark.
Now let’s feed that jpeg into the Topaz JPEG to RAW AI GUI
And now let’s look at a sectional 400% magnification comparison shall we
Sharpening artifacts again and noise that wasn’t there to begin with.
Seriously, you’d be better off tweaking your jpegs in Lightroom!
I do NOT recommend anyone purchase this Topaz product because it’s rubbish. But what concerns me is the manner in which it is being marketed; I see the marketing as just plain misleading.
I’m not dismissing all Topaz software – DeNoise is brilliant for certain tasks.
But Topaz JPEG to RAW AI is nothing short of misleading junk with a huge price tag – Christ, you could buy 12 months subscription to my Patreon Chanel for less!
When we shoot ETTR (expose to the right) in bright, harsh light, Lightroom can sometimes get the wrong idea and make a real ‘hash’ of rendering the raw file.
Sometimes it can be so bad that the less experienced photographer can get the wrong impression of their raw file exposure – and in some extreme cases they may even ‘bin’ the image thinking it irretrievably over exposed.
I’ve just uploaded a video to my YouTube channel which shows you exactly what I’m talking about:
The image was shot by my client and patron Paul Smith when he visited the Mara back in October last year, and it’s a superb demo image of just how badly Lightroom can demosaic a straight forward +1.6 Ev ETTR shot.
Importing the raw file directly into Lightroom gives us this:
But importing the raw file directly into RawTherapee with no adjustments gives us this:
Just look at the two histogram versions – Lightroom is doing some crazy stuff to the image ‘in the background’ as there are ZERO develop settings applied.
But if you watch the video you’ll see that it’s quite straight forward to regain all that apparent ‘blown detail’.
And here’s the important bit – we do so WITHOUT the use of the shadow or highlight recovery sliders. Anyone who has purchased my sharpening videos HERE knows that those two sliders can VERY EASILY cause undesirable ‘pseudo-sharpening’ halos, and they should only be used with caution.
The way I process this +1.6 stop ETTR exposure inside Lightroom has revealed all the superb mid tone detail and given us a really good image that we could take into Photoshop and improve with some precision localized adjustments.
So don’t let Lightroom control you – you need to control IT!
If you feel this article and video has been beneficial to you and would like to see more per week, then supporting my Patreon page for as little as $1 per month would be a massive help. Thanks everyone!
Over 11 hours of video training, spread across 58 videos…well, I told you it was going to be big!
And believe me, I could have made it even bigger, because there is FAR MORE to image sharpening than 99% of photographers think.
And you don’t need ANY stupid sharpener plugins – or noise reductions ones come to that. Because Photoshop does it ALL anyway, and is far more customizable and controllable than any plugin could hope to be.
So don’t waste your money any more – spend it instead, on some decent training to show you how to do the job properly in the first place!
You won’t find a lot of these methods anywhere else on the internet – free or paid for – because ‘teachers cannot teach what they don’t know’ – and I know more than most!
As you can see from the list of lessons above, I cover more than just ‘plain old sharpening’.
Traditionally, image sharpening produces artifacts – usually white and black halos – if it’s over done. And image sharpening emphasizes ‘noise’ in areas of shadow and other low frequency detail, when it’s applied to an image in the ‘traditional’, often taught, blanket manner.
Why sharpen what isn’t in focus – to do so is madness, because all you do is sharpen the noise, and cause more artifacts!
Maximum sharpening should only be applied to detail in the image that is ‘fully in focus’.
So, as ‘focus sharpness’ falls off, so to should the level of applied sharpening. That way, noise and other artifacts CAN NOT build up in an image.
And the same can be said for noise reduction, but ‘in reverse’.
So image sharpening needs to be applied in a differential manor – and that’s what this training is all about.
Using a brush in Lightroom etc to ‘brush in’ some sort of differential sharpening is NOT a good idea, because it’s imprecise, and something of a fools task.
Why do I say that? Simple……. Because the ‘differential factor bit’ is contained within the image itself – and it’s just sitting there on your computer screen WAITING for you to get stuck in and use it.
But, like everything else in modern digital photography, the knowledge and skill to do so has somehow been lost in the last 12 to 15 years, and the internet is full of ‘teachers’ who have never had these skills in the first place – hence they can’t teach ’em!
However, everyone who buys this training of mine WILL have those skills by the end of the course.
It’s been a real hard slog to produce these videos. Recording the lessons is easy – it’s the editing and video call-outs that take a lot of time. And I’ve edited all the audio in Audacity to remove breath sounds and background noise – many thanks to Curtis Judd for putting those great lessons on YouTube!
The price is £59.99. So right now, that’s over 11 hours of training for less than £5.50 per hour – that’s way cheaper than a 1to1, or even a workshop day with a crowd of other people!
So head off over to my download store and buy it, because what you’ll learn will improve your image processing, whether it’s for big prints or just jpegs on the web – guaranteed – just click here!
Become a patron from as little as $1 per month, and help me produce more free content.
Patrons gain access to a variety of FREE rewards, discounts and bonuses.
A lot of people imagine that there is some sort of ‘magic bullet’ method for sharpening images.
Well, here’s the bad news – there isn’t !
Even if you shoot the same camera and lens combo at the same settings all the time, your images will exhibit an array of various properties.
And those properties, and the ratio/mix thereof, can, and will, effect the efficacy of various sharpening methods and techniques.
And, those properties will rarely be the same from shoot to shoot.
Add interchangeable lenses, varied lighting conditions, and assorted scene brightness and contrast ranges to the mix – now the range of image properties has increased exponentially.
What are the properties of an image that can determine your approach to sharpening?
I’m not even going to attempt to list them all here, because that would be truly frightening for you.
But sharpening is all about pixels, edges and contrast. And our first ‘port of call’ with regard to all three of those items is ‘demosaicing’ and raw file conversion.
“But Andy, surely the first item should be the lens” I here you say.
No, it isn’t.
And if that were the case, then we would go one step further than that, and say that it’s the operators ability to focus the lens!
So we will take it as a given, that the lens is sharp, and the operator isn’t quite so daft as they look!
Now we have a raw file, taken with a sharp lens and focused to perfection.
Let’s hand that file to two raw converters, Lightroom and Raw Therapee:
I am Lightroom – Click me!
I am Raw Therapee – Click me!
In both raw converters there is ZERO SHARPENING being applied. (and yes, I know the horizon is ‘wonky’!).
Now check out the 800% magnification shots:
Lightroom at 800% – Click me!
Raw Therapee at 800% – Click me!
What do we see on the Lightroom shot at 800%?
A sharpening halo, but hang on, there is NO sharpening being applied.
But in Raw Therapee there is NO halo.
The halo in Lightroom is not a sharpening halo, but a demosaicing artifact that LOOKS like a sharpening halo.
It is a direct result of the demosaicing algorithm that Lightroom uses.
Raw Therapee on the other hand, has a selection of demosaicing algorithms to choose from. In this instance, it’s using its default AMaZE (Alias Minimization & Zipper Elimination) algorithm. All told, there are 10 different demosaic options in RT, though some of them are a bit ‘old hat’ now.
There is no way of altering the base demosaic in Lightroom – it is something of a fixed quantity. And while it works in an acceptable manner for the majority of shots from an ever burgeoning mass of digital camera sensors, there will ALWAYS be exceptions.
Let’s call a spade a bloody shovel and be honest – Lightrooms demosaicing algorithm is in need of an overhaul. And why something we have to pay for uses a methodology worse than something we get for free, God only knows.
It’s a common problem in Lightroom, and it’s the single biggest reason why, for example, landscape exposure blends using luminosity masks fail to work quite as smoothly as you see demonstrated on the old Tube of You.
If truth be told – and this is only my opinion – Lightroom is by no means the best raw file processor in existence today.
I say that with a degree of reservation though, because:
It’s very user friendly
It’s an excellent DAM (digital asset management) tool, possibly the best.
On the surface, it only shows its problems with very high contrast edges.
As a side note, my Top 4 raw converters/processors are:
Iridient Developer
Raw Therapee
Capture One Pro
Lightroom
Iridient is expensive and complex – but if you shoot Fuji X-Trans you are crazy if you don’t use it.
Raw Therapee is very complex (and slightly ‘clunky’ on Mac OSX) but it is very good once you know your way around it. And it’s FREEEEEEEEE!!!!!!!
Iridient and RT have zero DAM capability that’s worth talking about.
Capture One Pro is a better raw converter on the whole than Lightroom, but it’s more complex, and its DAM structure looks like it was created by crack-smoking monkeys when you compare it to the effective simplicity of Lightroom.
If we look at Lightroom as a raw processor (as opposed to raw converter) it encourages the user to employ ‘recovery’ in shadow and highlight areas.
Using BOTH can cause halos along high contrast edges, and edges where high frequency detail sits next to very low frequency detail of a contrasting colour – birds in flight against a blue sky spring to mind.
Why do I keep ‘banging on’ about edges?
Because edges are critical – and most of you guys ‘n gals hardly ever look at them close up.
All images contain areas of high and low frequency detail, and these areas require different process treatments, if you want to obtain the very best results AND want to preserve the ability to print.
Cleanly defined edges between these areas allow us to use layer masks to separate these areas in an image, and obtain the selective control.
Clean inter-tonal boundaries also allow us to separate shadows, various mid tone ranges, and highlights for yet more finite control.
Working on 16 bit images (well, 15 bit plus 1 level if truth be told) means we can control our adjustments in Photoshop within a range of 32,768 tones. And there is no way in hell that localised adjustments in Lightroom can be carried out to that degree of accuracy – fact.
I’ll let you in to a secret here! You all watch the wrong stuff on YouTube! You sit and watch a video by God knows what idiot, and then wonder why what you’ve just seen them do does NOT work for you.
That’s because you’ve not noticed one small detail – 95% of the time they are working on jpegs! And jpegs only have a tonal range of 256. It’s really easy to make luminosity selections etc on such a small tonal range work flawlessly. You try the same settings on a 16 bit image and they don’t work.
So you end up thinking it’s your fault – your image isn’t as ‘perfect’ as theirs – wrong!
It’s a tale I hear hundreds of times every year when I have folk on workshops and 1to1 tuition days. And without fail, they all wish they’d paid for the training instead of trying to follow the free stuff.
You NEVER see me on a video working with anything but raw files and full resolution 16 bit images.
My only problem is that I don’t ‘fit into’ today’s modern ‘cult of personality’!
Most adjustments in Lightroom have a global effect. Yes, we have range masks and eraser brushes. But they are very poor relations of the pixel-precise control you can have in Photoshop.
Lightroom is – in my opinion of course – becoming polluted by the ‘one stop shop, instant gratification ideology’ that seems to pervade photography today.
Someone said to me the other day that I had not done a YouTube video on the new range masking option in Lightroom. And they are quite correct.
Why?
Because it’s a gimmick – and real crappy one at that, when compared to what you can do in Photoshop.
Photoshop is the KING of image manipulation and processing. And that is a hard core, irrefutable fact. It has NO equal.
But Photoshop is a raster image editor, which means it needs to be fed a diet of real pixels. Raw converters like Lightroom use ‘virtual pixels’ – in a manner of speaking.
And of course, Lightroom and the CameraRaw plug in for Photoshop amount to the same thing. So folk who use either Lightroom or Photoshop EXCLUSIVELY are both suffering from the same problems – if they can be bothered to look for them.
It Depends on the Shot
The landscape image is by virtue, a low ISO, high resolution shot with huge depth of field, and bags of high frequency inter-tonal detail that needs sharpening correctly to its very maximum. We don’t want to sharpen the sky, as it’s sharp enough through depth of field, as is the water, and we require ZERO sharpening artifacts, and no noise amplification.
If we utilise the same sharpening workflow on the center image, then we’ll all get our heads kicked in! No woman likes to see their skin texture sharpened – in point of fact we have to make it even more unsharp, smooth and diffuse in order to avoid a trip to our local A&E department.
The cheeky Red Squirrel requires a different approach again. For starters, it’s been taken on a conventional ‘wildlife camera’ – a Nikon D4. This camera sensor has a much lower resolution than either of the camera sensors used for the previous two shots.
It is also shot from a greater distance than the foreground subjects in either of the preceding images. And most importantly, it’s at a far higher ISO value, so it has more noise in it.
All three images require SELECTIVE sharpening. But most photographers think that global sharpening is a good idea, or at least something they can ‘get away with’.
If you are a photographer who wants to do nothing else but post to Facebook and Flickr then you might as well stop reading this post. Good luck to you and enjoy your photography, but everything you read in this post, or anywhere on this blog, is not for you.
But if you want to maximize the potential of your thousands of pounds worth of camera gear, and print or sell your images, then I hate to tell you, but you are going to have to LEARN STUFF.
Photoshop is where the magic happens.
As I said earlier, Photoshop is a raster image processor. As such, it needs to be fed an original image that is of THE UTMOST QUALITY. By this I mean a starting raw file that has been demosaiced and normalized to:
Contain ZERO demosaic artifacts of any kind.
Have the correct white and black points – in other words ZERO blown highlights or blocked shadows. In other words, getting contrast under control.
Maximize the midtones to tease out the highest amount of those inter-tonal details, because this is where your sharpening is going to take place.
Contain no more sharpening than you can get away with, and certainly NOT the amount of sharpening you require in the finished image.
With points 1 thru 3 the benefits should be fairly obvious to you, but if you think about it for a second, the image described is rather ‘flattish – looking’.
But point 4 is somewhat ambiguous. What Adobe-philes like to call capture or input sharpening is very dependent on three variables:
Sensor megapixels
Demosaic effeciency
Sharpening method – namely Unsharp Mask or Deconvolution
The three are inextricably intertwined – so basically it’s a balancing act.
To learn this requires practice!
And to that end I’m embarking on the production of a set of videos that will help you get to grips with the variety of sharpening techniques that I use, and why I use them.
I’ll give you fair warning now – when finished it will be neither CHEAP nor SHORT, but it will be very instructive!
I want to get it to you as soon as possible, but you wouldn’t believe how long tuition videos take to produce. So right now I’m going to say it should be ready at the end of February or early March.
UPDATE: The new course is ready and on sale now, over on my digital download site.
A few days ago I uploaded a video to my YouTube channel explaining PPI and DPI – you can see that HERE .
But there is way more to pixel per inch (PPI) resolution values than just the general coverage I gave it in that video.
And this post is about a major impact of PPI resolution that seems to have evaded the understanding and comprehension of perhaps 95% of Photoshop users – and Lightroom users too for that matter.
I am talking about image view magnification, and the connection this has to your monitor.
Let’s make a new document in Photoshop:
We’ll make the new document 5 inches by 4 inches, 300ppi:
I want you to do this yourself, then get a plastic ruler – not a steel tape like I’ve used…..
Make sure you are viewing the new image at 100% magnification, and that you can see your Photoshop rulers along the top and down the left side of the workspace – and right click on one of the rulers and make sure the units are INCHES.
Take your plastic ruler and place it along the upper edge of your lower monitor bezel – not quite like I’ve done in the crappy GoPro still below:
Yes, my 5″ long image is in reality 13.5 inches long on the display!
The minute you do this, you may well get very confused!
Now then, the length of your 5×4 image, in “plastic ruler inches” will vary depending on the size and pixel pitch of your monitor.
Doing this on a 13″ MacBook Pro Retina the 5″ edge is actually 6.875″ giving us a magnification factor of 1.375:1
On a 24″ 1920×1200 HP monitor the 5″ edge is pretty much 16″ long giving us a magnification factor of 3.2:1
And on a 27″ Eizo ColorEdge the 5″ side is 13.75″ or there abouts, giving a magnification factor of 2.75:1
The 24″ HP monitor has a long edge of not quite 20.5 inches containing 1920 pixels, giving it a pixel pitch of around 94ppi.
The 27″ Eizo has a long edge of 23.49 inches containing 2560 pixels, giving it a pixel pitch of 109ppi – this is why its magnification factor is less then the 24″ HP.
And the 13″ MacBook Pro Retina has a pixel pitch of 227ppi – hence the magnification factor is so low.
So WTF Gives with 1:1 or 100% View Magnification Andy?
Well, it’s simple.
The greatest majority of Ps users ‘think’ that a view magnification of 100% or 1:1 gives them a view of the image at full physical size, and some think it’s a full ppi resolution view, and they are looking at the image at 300ppi.
WRONG – on BOTH counts !!
A 100% or 1:1 view magnification gives you a view of your image using ONE MONITOR or display PIXEL to RENDER ONE IMAGE PIXEL In other words the image to display pixel ratio is now 1:1
So at a 100% or 1:1 view magnification you are viewing your image at exactly the same resolution as your monitor/display – which for the majority of desk top users means sub-100ppi.
Why do I say that? Because the majority of desk top machine users run a 24″, sub 100ppi monitor – Hell, this time last year even I did!
When I view a 300ppi image at 100% view magnification on my 27″ Eizo, I’m looking at it in a lowly resolution of 109ppi. With regard to its properties such as sharpness and inter-tonal detail, in essence, it looks only 1/3rd as good as it is in reality.
Hands up those who think this is a BAD THING.
Did you put your hand up? If you did, then see me after school….
It’s a good thing, because if I can process it to look good at 109ppi, then it will look even better at 300ppi.
This also means that if I deliberately sharpen certain areas (not the whole image!) of high frequency detail until they are visually right on the ragged edge of being over-sharp, then the minuscule halos I might have generated will actually be 3 times less obvious in reality.
Then when I print the image at 1440, 2880 or even 5760 DOTS per inch (that’s Epson stuff), that print is going to look so sharp it’ll make your eyeballs fall to bits.
And that dpi print resolution, coupled with sensible noise control at monitor ppi and 100% view magnification, is why noise doesn’t print to anywhere near the degree folk imagine it will.
This brings me to a point where I’d like to draw your attention to my latest YouTube video:
Did you like that – cheeky little trick isn’t it!
Anyway, back to the topic at hand.
If I process on a Retina display at over 200ppi resolution, I have a two-fold problem:
1. I don’t have as big a margin or ‘fudge factor’ to play with when it comes to things like sharpening.
2. Images actually look sharper than they are in reality – my 13″ MacBook Pro is horrible to process on, because of its excessive ppi and its small dimensions.
Seriously, if you are a stills photographer with a hankering for the latest 4 or 5k monitor, then grow up and learn to understand things for goodness sake!
Ultra-high resolution monitors are valid tools for video editors and, to a degree, stills photographers using large capacity medium format cameras. But for us mere mortals on 35mm format cameras, they can actually ‘get in the way’ when it comes to image evaluation and processing.
Working on a monitor will a ppi resolution between the mid 90’s and low 100’s at 100% view magnification, will always give you the most flexible and easy processing workflow.
Just remember, Photoshop linear physical dimensions always ‘appear’ to be larger than ‘real inches’ !
And remember, at 100% view magnification, 1 IMAGE pixel is displayed by 1 SCREEN pixel. At 50% view magnification 1 SCREEN pixel is actually displaying the dithered average of 2 IMAGE pixels. At 25% magnification each monitor pixel is displaying the average of 4 image pixels.
Anyway, that’s about it from me until the New Year folks, though I am the worlds biggest Grinch, so I might well do another video or two on YouTube over the ‘festive period’ so don’t forget to subscribe over there.
Thanks for reading, thanks for watching my videos, and Have a Good One!
Become a patron from as little as $1 per month, and help me produce more free content.
Patrons gain access to a variety of FREE rewards, discounts and bonuses.
My YouTube Channel Latest Photography Video Training.
I’ve been busy this week adding more content to the old YouTube channel.
Adding content is really time-consuming, with recording times taking around twice the length of the final video.
Then there’s the editing, which usually takes around the same time, or a bit longer. Then encoding and compression and uploading takes around the same again.
So yes, a 25 minute video takes A LOT more than 25 minutes to make and make live for the world to view.
This weeks video training uploads are:
This video deals with the badly overlooked topic of raw file demosaicing.
Next up is:
This video is a refreshed version of getting contrast under control in Lightroom – particularly Lightroom Classic CC.
Then we have:
This video is something of a follow-up to the previous one, where I explain the essential differences between contrast and clarity.
And finally, one from yesterday – which is me, restraining myself from embarking on a full blown ‘rant’, all about the differences between DPI (dots per inch) and PPI (pixels per inch):
Important Note
Viewing these videos is essential for the betterment of your understanding – yes it is! And all I ask for in terms of repayment from yourselves is that you:
Give the video a ‘like’ by clicking the thumbs up!
YouTube is a funny old thing, but a substantial subscriber base and like videos will bring me closer to laying my hands on latest gear for me to review for you!
If all my blog subscribers would subscribe to my YouTube channel then my subs would more than treble – so go on, what are you waiting for.
I do like creating YouTube free content, but I do have to put food on the table, so I have to do ‘money making stuff’ as well, so I can’t afford to become a full-time YouTuber yet! But wow, would I like to be in that position.
So that’s that – appeal over.
Watch the videos, and if you have any particular topic you would like me to do a video on, then please just let me know. Either email me, or you can post in the comments below – no comment goes live here unless I approve it, so if you have a request but don’t want anyone else to see it, then just say.
Become a patron from as little as $1 per month, and help me produce more free content.
Patrons gain access to a variety of FREE rewards, discounts and bonuses.
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.
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
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!
Become a patron from as little as $1 per month, and help me produce more free content.
Patrons gain access to a variety of FREE rewards, discounts and bonuses.
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:
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:
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.
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:
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:
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 WHITEPOINT.
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:
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:
“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.
Become a patron from as little as $1 per month, and help me produce more free content.
Patrons gain access to a variety of FREE rewards, discounts and bonuses.
Learning how to deploy proper contrast control in Lightroom brings with it two major benefits:
It allows you to reveal more of your camera sensors dynamic range.
It will allow you to reveal considerably more image detail.
I have posted on this subject before, under the guise of neutralising Lightrooms ‘hidden background adjustments’. But as Lightroom CC 2015 evolves, trying to ‘nail’ the best way of doing something becomes like trying to hit a moving target.
For the last few months I’ve been using this (for me) new method – and to be honest it works like a charm!
It involves the use of the ‘zero’ preset together with a straight process version swap around, as illustrated in the before/after shot above and in the video linked below. This video is best viewed on my YouTube channel:
The process might seem a little tedious at first, but it’s really easy when you get used to it, and it works on ALL images from ALL cameras.
Here is a step-by-step guide to the various Lightroom actions you need to take in order to obtain good contrast control:
Contrast Control Workflow Steps:
1. Develop Module Presets: Choose ZEROED
2. Camera Calibration Panel: Choose CAMERA NEUTRAL
3. Camera Calibration Panel: Choose Process Version 2010
4. Camera Calibration Panel: Choose Process Version 2012
5. Basics Panel: Double Click Exposure (goes from -1 to 0)
6. Basics Panel: Adjust Black Setting to taste if needed.
7. Details Panel: Reset Sharpening to default +25
8. Details Panel: Reset Colour Noise to default +25
9. Lens Corrections Panel: Tick Remove Chromatic Aberration.
Now that you’ve got good contrast control you can set about processing your image – just leave the contrast slider well alone!
Why is contrast control important, and why does it ‘add’ so much to my images Andy?
We are NOT really reducing the contrast of the raw file we captured. We are simply reducing the EXCESSIVE CONTRAST that Lightroom ADDS to our files.
Lightroom typically ADDS a +33 contrast adjustment but ‘calls it’ ZERO.
Lightroom typically ADDS a medium contrast tone curve but ‘calls it’ LINEAR.
Both of this are contrast INCREASES, and any increase in contrast can be seen as a ‘compression’ of the tonal space between BLACK and WHITE. This is a dynamic range visualisation killer because it crushes the ends of the midtone range.
It’s also a detail killer, because 99% of the subject detail is in the mid tone range. Typically the Lightroom tonal curve range for midtones is 25% to 75%, but Lightroom is quite happy to accept a midtone range of 10% to 90% – check those midtone arrow adjusters at the bottom edge of the parametric tone curve!
I hope you find this post useful folks, and don’t forget to watch the video at full resolution on my YouTube Channel.
Become a patron from as little as $1 per month, and help me produce more free content.
Patrons gain access to a variety of FREE rewards, discounts and bonuses.
Even though I suppose I am rather tech-savvy for an old fart, I have major head-problems with most social media.
Facebook took me years to get the hang of..
And even though I have an account, followers and everything I simply CANNOT get my head around Twitter …. it makes NO f***ing sense to me at all!
Over the last year I’ve also been aware of the growing use by professional of this other “thing” called Instagram.
About two months ago I asked my son Richard to explain how it works:
“It’s simple Dad, it’s Twitter for images”………..I couldn’t work out who to shoot first, me or him.
But, after much grief I was eventually shown how to put an image on Instagram. I have an iPhone and an iPad but bare in mind it took me ages to work out how to put pictures on them.
And ALL mobile apps confound the hell out of me – so overly-simplified I find them difficult to use and I run out of patience!
So here I am looking at Instagram and seeing that I have to send an image to my iPad then I can upload it to Instagram – WTF????
I put a single image on there – it took me at least 30 minutes, and Rich was pissing himself laughing which didn’t help!
I tried a couple of programmes that were supposed to help put images on Instagram from a desktop machine, but they turned out to be more bloody complicated than the iPad method.
Needless to say I put Instagram on the back-burner.
BUT………………..someone has done something EPIC. They’ve made a Lightroom Instagram Plugin – and it works!
Simply click the download link, unzip the the file and copy the LRInstagram.lrplugin file to your Lightroom plug-ins folder.
Open up your Lightroom Plug-in Manager and click “ADD” then navigate to the file itself
and click Add Plug-in.
The plug-in will appear under Publish Services in the bottom left panel of your Library Module.
Click “Set Up”
Assuming you’ve actually got an Instagram account (if not then get one) all you need to do is fill in your account U/N and P/W and click Login:
Once logged into your account you need to set the export preferences – I actually leave them set as above (default) with added standard screen sharpening and a custom watermark.
Simply click ‘Save’ and you’re done!
Using the Lightroom Instagram Plugin is easy if you are used to any of the other publish services inside Lightroom, but if you want to see it in action here is a short video on my YouTube channel – if you are viewing this post via email then the video will not show up – read it on the blog itself
This Lightroom Instagram Plugin seems to work flawlessly and definitely speeds up and simplifies publish images to Instagram – all I need to do now is work out an effective hash-tag method!
Become a patron from as little as $1 per month, and help me produce more free content.
Patrons gain access to a variety of FREE rewards, discounts and bonuses.
To provide the best experiences, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behaviour or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Functional
Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes.The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
