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Wednesday, 18 June 2014

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Better - always leave a small colour chart (or grey card) somewhere unobtrusive before taking the photo.

Best . use Tri-x

As nearly always, I find it easier to start with the "curves" control (well, an adjustment layer). Moving one of the color curves a little up or down frequently produces a more natural effect than trying to balance shadow, midtone, and highlight adjustments in the "color balance" control (which is also available as an adjustment layer, and I use it that way). Also it's easier to start with a click of the gray dropper to get close, if you can find anything suitable (and I nearly always can, except in landscapes where I merely often can).

Praise the lord I stick to B&W. At least half of those looked fine to me...

An interesting tangent to this subject is the research involving male versus female color perception and ability, including factors such as eye pigment structure, evolutionary roles, etc.

We're apparently not born with equal 'visual intelligence'.


Your yellow cast actually looks good and warm. The magenta cast one looks exactly like my fist film I used (can't remember) when I was 10. A good lomo image for the net!

I'm red-green color blind and cannot always tell if there is a color cast problem. I have to ask others to view my images and tell me what they see--and then try to correct it. Very challenging.

Maybe I should be doing black+white.

Boy, does this bring back memories...I used to print color for a portrait studio when I was in college. Back then, I bought color viewing filters that Kodak used to sell, that you use to look at your work, by viewing through, and you could make some pretty good decisions on which way to go (they told you what to add or subtract)...pretty sure they haven't been available for years!

I had to smile when I read this post. Being magenta/green color blind means your sort of practice is a non-starter for me. Instead I use the La*b* color space to evaluate my images. By separating color and contrast I need only concern myself with two values instead of three. By learning acceptable a*/b* ratios for most non-neutral natural objects I'm able to color correct most images. Nonetheless it will come as no surprise that I much prefer to work in b/w.

A straight colour cast affecting all tones equally from dark to bright is the easy case. It will get nasty if the dark tones' cast is different from the the bright tones' cast—in other words, if the colour integrety is infringed. It's comparatively easy to identify the cast in the bright tones but it's difficult for the dark tones.

Read the articles about digital colour on the C F Systems website at http://www.c-f-systems.com/PhotoMathDocs.html (the maker of the ColorPerfect plugin for Photoshop; no affiliation beyond being a happy customer).

I have found it easier to learn the colours by using the tool within the editor (if your editor has it) that has all six colours in separate sliders in an HSL tool - cyan, magenta, green, blue, red, yellow. I started my learning process by simply pushing each slider to maximum and minimum saturation, and that would show me what if any of that colour was in the file. It especially helps with the subtle distinctions, such as between cyan and blue and the yellows and greens of grass. This approach is less of a mind-bender than the 3-slider use of opposite colours. That is not as straight forward and makes the learning curve steeper.

...problem with "white balance", is that there's "correct color" and there's "nice color"...the same reason I bracket, there's the "correct" exposure, and then the one that looks the best...

I learned color correction from "The Canyon Canundrum" by Dan Margulis. Dan makes a great argument that human vision works off opponent colors: yellow vs blue and magenta vs green. You might notice that Photoshop's RAW converter uses those two opponent colors rather than RGB's three. I wrote a tutorial about color correcting using Margulis's method tailored to Photoshop RAW rather than using curves in LAB Colorspace. You can read it here: http://www.photos4u2c.net/2011/01/23/how-to-set-white-balance-in-photoshop/

Yikes!
That's very C-print way of working. I can almost smell the blix. I certainly wouldn't use the color balance tool for color balancing.

I've sort of forgotten that the color balance tool was there. I always do color balancing with the curves tool if I'm in photoshop, taking advantage of the nice black, gray, and white point tools. You can also grab the red green and blue curves individually to do the same thing as the color balancing tool does with more finesse (IE you can really muck things up that way) which is good if you are color correcting copies of faded color prints (smelling that blix again).

In the splash photo I'd take the gray point from the brightest part of the splash since it represents a diffusion of all the light sources. If I knew that the house was white, I'd use that as a gray reference then bump the blue up a little because it's in the shade, and maybe the green down a bit because of so much green reflecting on it. My guess is that the mud in the water is reddish clay. Maybe not Oklahoma red but redder than California Central Valley mud which runs to blue-greenish gray. Oh, and the chromatic aberration makes it really hard to see whether the color is right or not.

The bike photo looks like it was taken just before sunset with really warm sidelight from the low Sun and sort of bluish skylight, so you are torn between realistic representation of the actual scene and light which is very orange, or the objects in the scene as your mind corrects them.

My experience is that the power transformer, and probably the building are predominantly neutral in color. The galvanized signpost is a cold gray most likely. I know the KIA logo is white and red. The concrete is probably kind of reddish is it is geographically close to that other photo. Since there is this big known white surface facing the camera and you know the photo is taken in the "golden hour" I'd take the gray point from the building wall.

Actually I usually do this sort of thing in Lightroom, which is completely different workflow.

One other thing, in Photoshop the fade tool (under edit) is your friend, sadly missing from lightroom as is a straightforward black point and white point tool, and really you should be doing this in layers which is way beyond the scope of a comment, even this one.

One other thing about the color balancer tool, it seems to be prone to producing images that have a color cast on one screen or printer that is different on another screen, even in a color managed environment.

As an learning exercise it might be useful, as were the Kodak color print viewing filter kits, but I never got clean results using them either, mainly because my brain would adjust to the color change too readily.
For that sort of thing, the Variations tool ( Image > Adjustments > Variations ) is way more useful, not that I ever use it except over the phone.

This is why I bought a Monochrom for my first electric camera.

But when I shoot digital color, I've been getting better about using one of those X-Rite Passport thingamajigs to correct color. You can set it up as a pre-set in Lightroom and apply it to all the other pictures you shot under the same lighting conditions and get pretty decent results, with half the aggro of adjusting each picture separately.

...or if you want the electronic instant-gratification version of the ColourCube try http://www.blendoku.com - horribly addictive!

Dear Richard,

Yeah, but the saturation's terrible. I can run the saturation slider all the way to max and I still see hardly any color in a Tri X scan.

Maybe it's just a bad batch of film. What do you think?

pax / Ctein

I had the good fortune to work at a professional colour lab as a printer for a few years. Our QA manager, a wonderfully kind and helpful woman, could call colour as well as anyone. Literally -- when she once went to "Pako School", (raise your hand if you remember Pako) she commented to the instructor that she could recognize as little as a one-half point correction. Which the the instructor didn't believe. But the denistometer proved her right.

I'm not sure I ever got that accurate, but I was usually within a point, and could colour correct my own work.

Whatever the software tools one chooses to accomplish correction, understanding the fundamentals and actually seeing colour is fundamental.

So thank you, and goodnight, Barb Arnold ... wherever you are.

Well, if you want a basic approach, this one is easy and works fairly well more often than not: http://www.markushartel.com/blog/learn-from-markus/easy-neutral-colors

[Boy, I wish more people knew about that. Gets rid of that horrible brownish-yellowishness of so many fluorescents-on-concrete and night shots. --Mike]

Once you've neutralized the colours, slide the tint toward magenta and temperature about 1.5x as far warm and pretend you shot it on Velvia...

I find the longer I stare at a picture, the harder it is to see the required correction (I guess the eye is compensating). When this happens I use the Photoshop auto color tool. This seldom produces the right result, but it can point you in the right direction and also helps reset your eye. Simple undo the auto correct and have another try at color balance.


If I want to see with a yellow cast, I shut my right eye and if I want to see neutral colors, I shut my left eye. That's because I had the cataract removed from my right eye a few months ago; cataracts have a yellow tinge. There's a distinct and strong difference, very noticeable when I look at my old paintings, but not so much with my photographs.

Unless I've screwed up the WB in my camera settings, the color's usually very good in Lightroom "as shot". For me, the "auto" in Lightroom is usually just a little on the warm side. Those two settings take care of 90% of my color adjustments. When they don't, the sliders do. The Spyder takes care of the monitor color balance.

It's just so easy to get good color now, such an improvement over developing color negative film, using those roller tubes for printing and the Kodak filters for judging corrections. I laugh when I look back.

'probably the result of having evolved on a green planet'

As alluded to by the marvellous Lorne Malvo (BB Thornton) in Fargo, it's because our ancestors needed to distinguish tones of green to identify and avoid predators.

Colour is the core PP skill. PS does it best (Hue Sat and esp. Sel Col, I use Joe's chroma spaces too), but LR/ACR are not bad. A common mistake is to remove nature entirely, often blue/cyan casts, then again I am a documentarian so rather biased to reality.

The key is to understand and see all other colours in each colour, and know how to adjust them optimally. I always start with fine-tuning WB on a 'neutral' file which accounts for so many colour issues, then work on keeping contrast low enough to not interfere with colour tones. Exposure > End points > tone distribution > WB > colour balance > micro-contrast (e.g. clarity) > finetune in PS, as psds often look different. Eye droppers are good as a guide only, IMO.

Mike, you may be interested in the fundamental question of how well you see color before you get to the issue of correcting the colors you see. There's a very good online test for that purpose at http://www.xrite.com/online-color-test-challenge.

I've taken the test a number of times over the years with occasional wild scores that got much better when I corrected my monitor with the Spyder.

There's a really fun little challenge here to see how well you can perceive and sort the hues in various gradients: http://www.xrite.com/online-color-test-challenge. (Obviously having a good and well-calibrated monitor will make it easier).

I am showing my ignorance, but I don't find an equivalent window with the 3 paired sliders (cyan-red, magenta-green, yellow-blue) in Lightroom. What am I missing?
Geof

Yes, and as mentioned there is room for interpretation. Most of the film simulation software such as DxO Filmpack introduce color casts to imitate various films color casts. I had never really noticed it much when I actually used film, but it is easy to see now. Since I have probably already committed an unforgivable photo forum sin by using such software, I often double the sin and leave it alone unless excessive.

Maybe I was too obscure with my analogy to a foreign language. I'm colorblind (strong protanomaly). I'm not a beginner, I have a strong background in color printing and digital technology. I know what I need to do, I just physically can't see what other people see.

Geof Margo: you will see this differently for a raw image or a non-raw image, but effectively, the White Balance temperature control slides the picture along a blue/amber axis, and the tint control along a green/magenta axis. So with a raw image you would depart from the standard white-balance "recipes" such as Daylight, or As Shot, and make a Custom WB for this particular picture. For a camera JPG, these are merely overlaid corrections, just
as the Colour Balance tool would be in Photoshop.

Assuming the colour rendition is generally OK, and you are just addressing a particular issue in a given photo, the WB is usually all you need to concentrate on. But for special pictorial effects or to rectify a calibration issue, there are lots of other ways to affect hue, and these work rather differently from each other.

Lightroom has per-channel saturation and hue-shift options in the Camera Calibration panel, though these are not really intended for picture-by-picture usage I think. Also the Tone Curve panel can be set to separate out the Red Green and Blue similar to Photoshop "curves". And specific parts of the hue spectrum can be tweaked more selectively, using the HSL panel. And choosing different camera calibration profiles (for raw) will alter the basic colour character onto which these adjustments are overlaid.

Yes, what Hugh Crawford said. As long as your monitor is calibrated, and you take break to give your eyes a chance to see the image fresh, and you look at some proof prints as a final test for important images, it's all to taste. I often click around with the gray Curves tool until I find what I like -- I prefer a warmish image.

But I also believe in shortcuts because life is short, and here's one that works when I find a challenging image: In Photoshop, open Image -> Adjustments -> Match Color and check the Neutralize check box. Voila. It's like some sort of weird miracle. If that doesn't work, you can't tweak it, you have to start over, but a lot of times, it's spot on. Unfortunately it doesn't work as an adjustment layer, so there's no going back. You Photoshop purists will want to use it on a copy of your background layer.

Nice post and comments.
A classic book on color theory from the art world is Josef Albers' 1963 classic "Interaction of Color". It was an early "interactive" book on color theory and It's been republished in book form, interactive book (pricey) and, my favorite, an affordable interactive iPad version http://yupnet.org/interactionofcolor/

Ctein,
If you will use color filters with your Tri-x, they make red, green, and yellow that I am aware of you may have some chance of adding to that color on your Tri-x. And thanks to Mikes excellent explanation you now know what color using each will produce. I would lend you mine but they are all 52mm, a size lenses are no longer made in.
Good Luck,
Jim

Got this on my first try! Not bad for just having my 56th birthday.

It took me a mere 5 years to understand the importance of setting the white point in Lightroom. When I did I also found that I could identify the blue/yellow and/or green/magenta movement required to neutralize any cast I was seeing - and to see the cast itself. I've learned to use the gradient and brush tools to adjust localized cast in shadows. Often the color under a roof overhang, for instance, is much cooler than the sunlit portion of a building so using these tools offers the chance to even the tone if I wish.

The color balance sliders work well, their strength is in their repeatability. Curves are much more complex; although you can do more with them you can make more mistakes as well.

Don't forget to use the shadows and highlights button as well. Very good for consistent sepia tones from desaturated files (Red shadows +20, Red Middle +10, Blue Highlights -20), make it into an action and it's the same every time.

Like DaveB above, I am red-green colour blind. It makes all of this an awkward subject. I'd stick to black and white, except that I do like colour. I live in a colour world, and the colours I see are no less fascinating to me than to a person who sees colour more accurately. And so, I muddle through.

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