Balancing colour in highlights, midtones and shadows

[adam z]

Ok, so what I want to know is how to adjust skin tones so that the colour balance is the same all over the subject. I find it frustrating when I shoot a person in shade with sunlight coming through a window and I end up with the shadow tones obviously cooler than the highlighs/midtones. If I adjust the white balance to be correct for one part of the subject, then another area is off. Sometimes it is insignificant, but in some images it is quite obvious. This can also be noticed in some shots where daylight and flash are mixed. A good example of this would be when an overcast day cools the areas lit only by natural light. At sunset for example, it is the opposite and shadows are warmer than the flash lit area.

I know when using flash, one solution is to gel the flash to balance with the natural colour. I guess using a second flash of the same colour temp as the first as fill could work, but often a second light is not practical or is not wanted at all.

So, what techniques are useful in post to balance things out when you don't have the options to correct in camera (for flash), or if just shooting natural light as mentioned close to the top of the post.

I hope this all makes sense, as I am trying to move my portrait photography to a higher level of quality and I think this could make some difference.

[stamper]

Masking the colours is the answer. Learn masking techniques in PS or buy Viveza 2. That works well if the masks aren't too tricky.

[adam z]

Thanks for that. I am assuming feathered masks would be the way to go. How would one ensure colour balance is accurate between different areas though. I suppose if it looks right, then it is probably good enough - but I like perfection where possible. Is it best to work with numbers (RGB values) If so, that may get complex. Not that I mind learning, I just need to find a source of information on how best to approach it.

[Tim Lookingbill]

Could you post a sample image to show exactly what you're talking about with regard to shade and window light affecting overall skin uniformity?

I get the feeling you may be making this too difficult than it has to be.

You could shoot Raw and adjust the Split Tone sliders in ACR/Lightroom along with Color Temp sliders.

[Slobodan Blagojevic]

I can see the rationale for flash combinations, but I think that correcting natural light would be counterproductive. The color of the shadow is an inherent attribute, and adds a color contrast to the image and adds three-dimensionality to it. As much as highlight/shadow contribute to the 3D, so does the color contrast (warm colors advance, cool recede). In other words, be careful what you wish for.

As an aside, when I was shooting landscape on film (transparencies), I would often deliberately remove a UV filter (which is supposed to cut the blue in shadows) for sunrise/sunset shots, in order to enhance color contrast and 3D.

However, if you insist, you might try (in addition to the masking and split toning suggestions above) to change the Camera Calibration Profile in Lightroom. I found that Neutral and Faithful reduce contrast and saturation quite nicely.

[Etrsi_645]

I once saw a technique where in Photoshop you open a curves adjustment layer and with a modifier key (which one?) you can place a point on all three RGB layers at the same time with one click for the relevant highlight area.  Then--with the info palette open--you go into each curves RGB channel and balance the numbers until they are all equal on the info palette (or within about 1 numerical value of one another).  Now do all the same for an important shadow area.   Changing the shadows values may alter the highlights again that you would want to check their numbers again and tweak if need be.

[stamper]

I once saw a technique where in Photoshop you open a curves adjustment layer and with a modifier key (which one?) you can place a point on all three RGB layers at the same time with one click for the relevant highlight area.  Then--with the info palette open--you go into each curves RGB channel and balance the numbers until they are all equal on the info palette (or within about 1 numerical value of one another).  Now do all the same for an important shadow area.   Changing the shadows values may alter the highlights again that you would want to check their numbers again and tweak if need be.

With this technique they don't have to be equal, A neutral image isn't possible in reality.


>Thanks for that. I am assuming feathered masks would be the way to go. How would one ensure colour balance is accurate between different areas though. I suppose if it looks right, then it is probably good enough - but I like perfection where possible. Is it best to work with numbers (RGB values) If so, that may get complex. Not that I mind learning, I just need to find a source of information on how best to approach it. <

Feathered masks? Yes. But accurate colours? No. What is accurate? Every channel balanced? A colour cast is part of every image you shoot so the cast should be diminished but not eliminated.

[adam z]

Hmm, perhaps I am being ridiculous. I might play around with an image in LR using the split toning controls (have only ever used them to tone B&W images before). If I like the results I may continue to push things further. At least I will know if I like the way it is headed. Perhaps once I see the results I won't like it as much as I was originally expecting to. If I come across a suitable image to post in the next few days I will post it, but don't have time to go looking right now.  BTW I think it is right that I probably shouldn't aim to totally neutralise the differences, just lessen them. When I mentioned accurate skin tones I mean ones that look as accurate as possible OR perhaps adjusted slightly to look most pleasing. As you all know, sometimes accurate isn't as nice as a subtle warming of the skin tones on a portrait.

Thanks for your thoughts everyone.

[leuallen]

Watched Amy Dresser do a retouch from start to finish in a RetouchPro live demonstration video. Watched her a couple of times, actually. She is amazing. What she does for color and density variations is to very roughly outline the affected area with a lasso and then feather 30-100px depending upon the lassoed area. Then use an curves adjustment layer with the lassoed area as a mask. The adjustment might only be a couple of points in one of the colors or density. She repeats this as many times as she thinks it takes to do a good job. That might be 30 or more layers. Seems excessive but it really works. She does not go back to a layer and tweak, she just puts another layer on the stack for the tweak. It is really quite fast considering. The key is an irregular lasso shape with plenty of feather so that it is not a noticeable alteration. It takes a lot of practice to master what color, density, lasso size, and feather size to use, but once you do it enough it becomes intuitive.

She works very loosely and intuitively. Her art background helps. After watching her I began to get much looser myself with better results. I used to be very technical and precise, not so much anymore.

Larry

[feppe]

Getting it right in camera is a good rule of thumb, but it's not always feasible or even possible - and seems to be going out of fashion the more powerful post-processing software gets. Oh and a Colorchecker is a huge timesaver to get the overall skin tones right!

Google "skin by numbers," there are a couple of good articles about that. Drop an eye dropper in each of the affected areas. Unlike some tutorials do, you don't have and shouldn't convert the image to HSL (lossy) unless you work in HSL all the time. You can view the eye droppers in HSL without converting color spaces (click next to the RGB figures in the Info panel).

Then slap a curves layer and start working on each of the channels. It's tedious, and a tweak in red channel shadows might result in a another tweak in blue midtones, which might cause another tweak in green highlights... You get the idea. Photoshop's coarse (low resolution) curves system isn't very helpful, and Lightzone's approach is much better, but that's another story. But it eventually gets the work done.

What Larry above suggested from Amy Dresser's tutorial sounds like it might be workable, if inelegant option to do the same as above with multiple curves layers instead of just one. I'll try that next time I have that issue. Pixel peepers would balk at the errors produced by the multiple adjustment layers

Finally, believe your eyes. Take a break and come back later to see if it still looks the way it's supposed to. You probably don't want to go for a purely neutral look. As Slobodan suggested, most people want a natural look, and shadows have different color temp than highlights, especially in mixed lighting.

Then there are some who want a clinical look, just like there are architectural photographers who insist on "fixing" converging verticals although that's how we see them in real life...