Green Screen Spillage
shatch
Registered Users Posts: 798 Major grins
I'm fighting the green spill onto my little girl. I know my selection is extremely poor at this point, I need help with correcting the green spillover on to my daughter (hair and hands especially). Please help! Wife is anxious to have these.
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Hi Shatch,
I converted to LAB, then used a hue/sat adjustment layer. I selected the greens with the dropper and changed the hue of the greens to -40 and increased the lightness a bit. Then I set the blending options of that layer to only blend if the underlying layer's A channel was negative (green) with a slight range into the the reds to avoid artifacts. There were still a few areas I didn't like, so I used a second hue/sat layer on those, and then mucked a bit with the opacity till it looked OK. I think the dress would have looked better if I had incresed the lightness a bit more.
This method was quick and dirty. As usual, it took less time to do than to describe. I think it looks better than the original, but you may have gotten better results with the color balance.
BTW, that's a great shot.
Thanks for working on this one. I like your approach much better than mine. The extra flexibility is very nice. Thanks again.
Anyone want to share their secrets of shooting "green screen" with minimal to no green spillage?
Some of My Photos: app.electrikfolio.com/v/steven-hatch
Try to keep the front light spill away from the b/g.
Even lighting across the entire surface of the green screen.
Try to use other primary colros on the subject so automated selecrtions are easier.
I'm shooting blue screens right now in my wifes studio. And these things have helped. It hasn't been as tough for me to select the entire b/g as it seems to be for you though.
All the best,
-Jon
A fast two step approach was used below.
1. Add a color blend mode hue/saturation adjustment layer, go to the green hue edit menu, use the +eyedropper to custom select the range of green spillage in the image and the hue angle was adjusted to -40. This removes most of the green spill issue.
2. A new blank layer was added above the adjustment layer, this blank layer was also set to color blend mode (so as to preserve luminosity). The clone tool was used to sample nearby clean tone and to paint over any stray bits left. The paint brush can also be used, sampling the hair or skin colour etc.
This is best done on the extracted, transparent layer file so that the colour blend retouching is only applied to the opaque pixels (transparency lock) and not to the other pixels/layers as when retouching the flat image.
This method usually provides fast results with very good quality with minimal hue changes etc. One can take more care in the hue/saturation step, by placing fixed colour samplers in key areas of both affected and unaffected areas, and viewing the info palette sampler in HSB or LAB mode, one can then tweak the yellow hue to be the same as before the green hue adjustment (which may affect the yellow hue, hope this makes sense).
If your final composite has banding in the radial gradation, you may need to add some noise to the gradation layer to break up the contours, or even better - "smart noise" (linear gradients usually suffer less from banding than radial gradations):
http://members.ozemail.com.au/~binaryfx/howto_smartnoise.html
Good luck,
Stephen Marsh.
http://members.ozemail.com.au/~binaryfx/
http://members.ozemail.com.au/~binaryfx/
http://prepression.blogspot.com/
BinaryFX, thanks for your detailed approach to fixing my "green" problem. I need to print it out and follow it to see it play out and add it to my "bag of tricks". Thanks again for your time and knowledge sharing.
Some of My Photos: app.electrikfolio.com/v/steven-hatch
I think the trick is to put some distance between your subject and the screen so that the light reflected off the screen is dark compared to the light on your subject. Ideally your screen should be far enough away that it requires separate lighting. When you can't get enough separation, a neutral backdrop is often a better choice.