Correcting skintone in ACR

[teajae]

Hello all,
I know there are a lot of great skin tone correcting techniques for photoshop using CMYK values but I do a lot of batch editing and I was wondering if there is anyway that the RGB color readouts of a point on an image in Adobe Camera Raw could help me out in trying to evaluate correct skin tone. I read this article that really helps me out in the direction that I need but the problem is that I'm using ACR which only reads out the RGB values in the sRGB color space rather than the percentage values of Lightroom's Melissa RGB color space like the article shows. Does anyone have any RGB relations that would get me closer to getting more realistic skintones?

[mistermonday]

Re: Correcting skintone in ACR

I would recommend that you set the eyedropper in the Info window to display LAB instead of RGB or CMYK. Instaed of 3 (RGB) or 4 (CMYK) numbers to look at, you only have 2 in LAB - the A and B channels. There is a very simple relationship that you learn to spot immediately. Skin means A and B are always both positive. There is a reliable relationship between those two numbers. When the value of A exceeds B, the skin starts turning magenta. Normal skin usuallu has B anywhere from equal to A up to about 50% greater than A. And as A and B approach zero the skin gets paler with 0,0 being the neutral point (white or gray depending on the Brightness value in the L channel).
The numbers never lie.
Often you only need to correct the white balance for everything to fall into line. However very often cameras are over sensitive to red and people skin can often be more red / magenta than you would like. When the white balance is correct but you still have magenta or other cast in the skin, the HSL Tab in LR / ACR will very easily fix it.
Cheers, Murray

[teajae]

Re: Correcting skintone in ACR

Thanks for your reply Murray!
Since I often color correct hundreds of images at a time I am not going to use photoshop in the process, sadly :/. Even though I do use a gray card at the shoot to set the white balance, the skin tones usually don't look very lively and appealing to me and I end up tweaking the WB and saturation in order to get a more realistic and desirable look. Rarely, though, I will look into the HSL sliders and boost some orange saturation if needed.

[andrewrodney]

Re: Correcting skintone in ACR

You don't need to mess with CMYK (which isn't available in ACR).

Here's a video on correcting skin tones without having to resort to CMYK:

Low Rez (YouTube)

http://www.youtube.com/watch?v=dWaFDKrNrwc

High Rez

http://digitaldog.net/files/SkinToneVideo.mov

[andrewrodney]

Re: Correcting skintone in ACR

http://digitaldog.net/files/LR_Skintone_Ratio.jpg

[teajae]

Re: Correcting skintone in ACR

http://digitaldog.net/files/LR_Skintone_Ratio.jpg

That's really helpful Andrew, thanks
I guess I just need to start using LR for my batch editing I suppose. And I've always heard of the LAB color space but I've never thought of using it for work on photos. How I'm understanding it is basically like the WB sliders in ACR but with brightness included (L)?

[andrewrodney]

Re: Correcting skintone in ACR

How I'm understanding it is basically like the WB sliders in ACR but with brightness included (L)?

Kind of yes. You can see the various axis's that do correspond to Lab (Tint/Temp).