D. L.,This is looking great so far. Is it possible for you to post the reference photos? This is an amazing undertaking to combine this many different photos. Were they taken under different lighting conditions?
At this point, I would try to add a bit more shading in the halftone areas. In other words, find just 3 or four of the brightest spots on each of the children and add lightly add tone up to these spots. This will make their faces look less washed out. If the lighting is different for each child in your reference photos, you may have to improvise the placement of some of these highlights. You should also make sure they all have a common shadow side on their face.
Would you post the drawing of the little girl you did a while back. I think everyone here would like to see that as well. YOu can start a new thread for that one.
Keep us posted on your progress. It's good to have you with us.
J. D.
J. D. Hillberry
http://www.jdhillberry.com
