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#1
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Cave canem!
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One click color balance howto
Some people worry about getting color balance right when they are shooting. Some people never worry about color balance. And lots of people already know a lot about color balance. If you are in this third group, you probably won't get much from this post; it's meant for the first two groups.
If you shoot raw (and even if you don't) you don't have worry that much about color balance until you process your pictures. It's pretty easy to correct color balance after the fact. In fact, if you shoot raw, you haven't made any irrevocable color balance decisions at all. Easy color balance in Adobe Camera Raw When you first open your raw image in ACR, you will see a dialog something like this: ![]() The first thing to try is to let ACR automatically color balance the image. Select Auto from the White Balance pull down menu. Better? ![]() If it is better (and even if is only different) it's a clue that your camera's automatic white balance can be improved on. Does your image contain anything that you know is a neutral color (black, white, some neutral shade of gray?) If so try selecting the first dropper tool and clicking on that part of your image: ![]() Here I tried clicking on different parts of his hat. One click color balance in Photoshop curves Photoshop curves may seem intimidating for beginners, but it does have one easy trick which is worth knowing: one click color balance. Bring up the curves dialog with Image->Adjustment->Curves. Then select the middle dropper and you can point at a neutral area of your image (just like in ACR) and you'll automatically get curves that make that part of the image really neutral: ![]() Don't be afraid to try None of the things I've suggested here are final. You can always reselect As Shot or Auto for White Balance in ACR. You can always undo the curves edit in PS. So it's conservative to try them and see what you get. What's not conservative is accepting what you get from the camera without trying at least some of these things. You may pass up an opportunity to improve your picture a lot! Further refinements Once you have done one of these things, you will have your color balance at least on the right planet. But there is more potential for improvement, especially in pictures of people. See this thread for one next step in people photography. There are some other situations which can lead to problems, in particular no neutral colored objects in the image and/or light from different kinds of sources. I'll try to write something about this soon. But these kinds of problems are rare enough. If you've tried the things I've already suggested, chances are you've already gotten most of the available improvement.
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If not now, when? Last edited by rutt; Apr-24-2009 at 08:36 AM. |
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#2
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Major grins
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Quote:
I do agree, if you shoot Raw, you don't need to worry about color balance until you process (create the RGB pixels).
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Andrew Rodney Author "Color Management for Photographers" http://www.digitaldog.net/ |
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#3
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Major grins
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To set the gray point in Curves I often use Dave Cross's procedure of filling a layer with 50% black and then adding a threshold adjustment layer (as explained in Kelber's "Photoshop CS4 Book for Digital Photographers" on page 219).
However, it seems to work to just use the Color Sampler eyedropper and just skim over the image looking for a spot that reads as close to 214-214-214 as I can. It also finds 0-0-0 for black and 255-255-255 for white. It's not always possible to find these exact readings, but close works. |
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#4
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Cave canem!
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The main reason for this thread was to have something to link to when making people aware of color balance for the first time.
Better to correct color balance, however imperfectly, than not at all. All this seems very easy to us, but shooting raw, worrying about WB at shoot time, it can all be overwhelming at first. Let's not forget that. Quote:
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If not now, when? |
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#5
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Cave canem!
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Help improve this tutorial
I only know how to do this in Photoshop and ACR. But I'd like to include descriptions and screenshots for other software, especially other raw converters. So if you know other how to do this with other software, please post and I'll edit it into the main message. Eventually, perhaps, this will become an official dgrin tutorial and you will have helped!
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If not now, when? |
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#6
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Drive By Digital Shooter
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Quote:
I have tried this technique a number of times, and I can do it in my sleep, but I just have not found it REALLY helps me get better color balance more than rarely, after I have run through ACR and set black and white points.
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Pathfinder - www.pathfinder.smugmug.com Moderator of the Technique Forum and Finishing School on Dgrin |
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#7
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Mildly bemused
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Quote:
![]() On the other hand, looking for an area that can be assumed to be neutral and clicking on that to set the white balance has generally worked well for me. I wasn't aware that the center dropper in a curves layer had this effect. I almost always do white balance in ACR, but it's good to know that there's another option once in PS.
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#8
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Major grins
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[quote=pathfinder]This is where you do a Difference Blend with the 50% grey layer and then a Threshold command to find a true 128,128,128 gray spot? I have a video link for that somewhere.
You add a blank layer above the image, fill with 50% gray, change blend mode to DIFFERENCE, then add a Threshold Adjustment Layer. Move the triangle to the far left, then back to the right to the place where image starts to appear. That should be the 128-128-128 Gray point. I have most of it (except for the moving of the triangle) assigned to a function key. The one thing that confuses me is that 18% Gray, the color on a Gray Card, is 214-214-214. So which gray do we search for? Whether I use the long method or the short method, I still eyeball for the final decision. |
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#9
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Drive By Digital Shooter
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Tony, you don't use a gray card for the method I was talking about - Here is the link for the video - http://www.youtube.com/watch?v=Se3htZz2noo
You set your gray value to 128,128,128 or some choose 133,133,133 and set it in your eye dropper values in the Curve dialogue box, where you have set your white point to 248,248,248 ( or thereabouts ) and your black value to 6,6,6 - Black and white are really determined by what you can clearly see your printer print on paper with your printer/paper choice. I agree with Richard, I never understood why this technique should work if there is a cast in the midtones to begin with. The mid tones would then have a cast, and if you found a true gray, it would only be 128,128,128 after being altered by the cast color to start with. I think this was an attempt to help balance those image in which we cannot easily identify a white, or a black, or a true neutral point. Those images can be tough to get color balanced well.
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Pathfinder - www.pathfinder.smugmug.com Moderator of the Technique Forum and Finishing School on Dgrin |
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#10
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Drive By Digital Shooter
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In reply to John's initial posts at the top of this thread, I use the eye dropper for white balancing routinely, BUT I frequently jot the Temp and Tint values selected by the white eye dropper down on a sheet of paper or in a text file, and compare those to the As Shot numbers, and sometimes find I split the difference a bit, hedging one way or the other.
I do not Click on the Auto button, for my experience, I rarely like or use the Auto button choice. I am not sure what this really means, but I do not rec using the Auto button as my first step for myself anyway.
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Pathfinder - www.pathfinder.smugmug.com Moderator of the Technique Forum and Finishing School on Dgrin |
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#11
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Drive By Digital Shooter
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Quote:
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Pathfinder - www.pathfinder.smugmug.com Moderator of the Technique Forum and Finishing School on Dgrin |
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#12
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Still learnin'still lovin
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Quote:
My worst case was when I accidentally chose a fluorescent WB in an incandescent setting and shooting JPGs. I was only successful in recovering some of the images. Thankfully it was not during anything important and nobody expected to see the images anyway. I learned the lesson was all. |
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#13
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Drive By Digital Shooter
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You really have to be careful shooting indoors these days, as tungsten lights are disappearing rapidly, and being replaced with Compact Fluorescent Lights, that can look much like tungsten lights look, but are not quite as green as real fluorescent tubes, and not work well with either tungsten or fluorescent balances on your camera.
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Pathfinder - www.pathfinder.smugmug.com Moderator of the Technique Forum and Finishing School on Dgrin |
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#14
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Major grins
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[quote=pathfinder]Tony, you don't use a gray card for the method I was talking about - Here is the link for the video - http://www.youtube.com/watch?v=Se3htZz2noo /QUOTE]
That's exactly the procedure I was referring to, and what I do sometimes use. The video mentions that Dave Cross came up with the last part just as I mentioned in my post. It's in Kelby's book. As far as the gray card, I know what that's for, and I use that technique sometimes when the situation allows me to. What I was pointing out is that Cross's system uses 50% black at 128-128-128. However, when we put an 18% gray card in the scene, and use that, we are using 214-214-214. Two different methods of getting to the same place. It does baffle me that 128-128-128 will work if you use the Cross version in post, but 214-214-214 will be the gray point when you include a 18% gray card in the scene at the time you take the image. Quote:
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#15
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Cave canem!
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Quote:
Although I do agree that it's generally better to start with raw images, I don't agree that it's always better. In my experience, setting WB to auto on the camera very often gets results close enough to be easily corrected. For that matter, one click color balance is also limited. Images with mixed casts often need some sort of special consideration other than just choosing one of the light sources. This is all about batting average. Knowing that color balance is an issue which can often be improved in post can result in a huge improvement in many pictures, even if only the jpegs are available. Knowing that shooting raw leaves the color balance decisions entirely to post cuts further into the percentage of images which are hard to fix. Learning how to handle images without obvious neutral targets again decreases the number of unaddressed problems. Addressing mixed casts will further improve one's batting average. There will always be some pictures which can't be saved in post no matter how great the expertise we bring to them.
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If not now, when? Last edited by rutt; Apr-25-2009 at 05:07 AM. |
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#16
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Cave canem!
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Quote:
I know it's really hard for us to remember a time when we would have looked at, say, an image shot under tungsten with WB set for sunlight, and not noticed that there was a problem. But, I remember the early days of dgrin and it happened quite a lot, even to moderators. Recently, I've been exposed to another group starting down the digital photography path and noticed how surprised they often are when the color balance of their shots is corrected. I really want to make clear that this thread is aimed at producing a tutorial for this stage and not for the normal denizens of the Finishing School who really don't need it.
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If not now, when? |
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#17
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Drive By Digital Shooter
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Quote:
I am not trying to cause trouble, John, I suspect you are correct that the Auto button in ACR works better for some cameras than others, and I am sure it has gotten better with the newer profiles available in ACR 5.3, so I should have qualified my statement also. I agree that the As Shot is better for the 5DMKII than some of the earlier cameras. I have been very, very impressed with the AWB setting in mixed lighting from the Nikon D3 and D700 as well
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Pathfinder - www.pathfinder.smugmug.com Moderator of the Technique Forum and Finishing School on Dgrin |
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#18
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Cave canem!
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Quote:
I suppose I could show images with poor color balance and what happens when they are fixed before I even get into the nuts and bolts of how to fix them. I'm really after the people who can look at a picture of a poached egg shot under tungsten and balanced for sunlight and balanced for sunlight without noticing that something is wrong (or if they do, not knowing what.) It might be hard to remember, but we've all been there. Take a trip in the wayback machine if you have trouble remembering.
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If not now, when? |
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#19
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Major grins
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While the original example above shows improvements, no question, one could argue its not too far off to begin with. That's why I commented about JPEG versus Raw. I suspect in the above example, either format would produce good results. I suggest you start with an image that has a pretty severe cast, something shot under tungsten with daylight as the assumed WB tag for both JPEG and Raw. This is a pretty common problem for users. Ideally have something in the scene that has both a gray (what's supposed to be pretty close to neutral) and non specular white. I suspect you'll see, as I have over the past, that correcting via a single click is far less effective on the JPEG. I think you also could then point out that, depending on if the image is JPEG or Raw, the differences in doing this click balance on gray versus white. In gamma corrected images (JPEG), you want to gray balance. On Raws you want to white balance. Yes, this might be more than you want to get into with beginners but its pretty crucial. Also, JPEGs in Camera Raw/Lightroom while gamma corrected, are having their edits applied in a linear color space. Again, while you don't necessarily want or need to go into detail for this audience, it might be useful to recommend doing the work in either ACR/LR or Photoshop (the later of course applying the edits in a gamma corrected space). Lastly, I often find that even with "proper" WB or GB, the color appearance needs an additional tweak, such as a bit of warming with tint/temp sliders or the image looks "too cool". If you're shooting a Macbeth color checker, a gray seamless etc, dead nuts neutral gray might be necessary. But with a lot of images, dead nuts neutral gray needs a slight additional edit to taste. Its subjective of course.
Bottom line is, while the goal may be to produce a very quick and easy tutorial for beginners, there's a lot more under the surface here that might need to be defined. No question that taking an image with a color cast in either Photoshop or ACR, doing a GB or WB will very likely improve the image a great deal. But often I find, that's only getting 95% to the final goal. Depending on the audience, you might want to go into detail about the differences above or simply say "you might find you need to season to taste after the balance". Quote:
Quote:
__________________
Andrew Rodney Author "Color Management for Photographers" http://www.digitaldog.net/ |
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#20
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Cave canem!
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Quote:
Even getting to 80% of the goal 80% of the time would be success for this particular tutorial. I really just want people to be aware that there is an issue and that there is something that can be done about it. Once they get that, they can go on to some more advanced tutorial where all kinds of additional issues are pertinent. Suppose someone just unpacks his/her new camera and starts to shoot. Maybe it doesn't even have a raw mode (they make those, you know.) Now s/he is looking at the jpegs and thinking they look OK (see the wayback thread I linked above.) S/he shares with one of us and we notice a color balance issue. What's the first thing we'd like him/her to know? That's the point of this proposed tutorial. So we can say, "I'll send you a link." It would be nice if it had something easy to try on the pictures in question which had a high degree of likelyhood of success and which could be applied to what s/he actually has. If it's only jpegs, it may not be perfect, but it will very likely be better. Once that happens, the person will eventually read past the quickstart and follow some links to learn more, perhaps learn to shoot in raw, perhaps learn how to tweak, perhaps learn how to check for magenta flesh, perhaps learn about mixed casts. Maybe it's hard to imagine what a baby step I'm working on. But recently I've encountered people who would be happy with just this sort of help. And, yes, I do need some more obviously wrong examples. I'm working on getting the poached eggs under tungsten (a real example I encountered recently, just as described above.)
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If not now, when? |
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