So, I spent the past week working in ArtRage doing the background, trees, and leaves. With the leaves all in place it's now easier for me to switch back to Photoshop to add the leaf shadows. I could paint them in ArtRage (or Photoshop) one shadow at a time. But the thing I don't like about painting shadows on top of existing leaves is you lose that detail continuation between shadow and light. The veins and texture on the leaves, for example, you want to continue from dark to light unbroken. If you repaint the dark areas those veins and textures tend to not line up quite right anymore and you get a separated look. In traditional oil painting you might just go back and give some areas a darker wash if you want to darken them without obscuring the existing detail. So this is sort of what I'm going to do in Photoshop.
So here's a version of the painting before I apply my "shadow wash" to the leaves and tree.
Now in this next image (besides adding more leaves to the ground) I've added shadows to the leaves, tree trunk, and branches.
To do this I kept my leaves on separate layer when bringing the image in from ArtRage to Photoshop. I used that leaf layer to create a selection. Then I created a new layer to paint my shadows on. The selection created by the leaves keeps my shadows only on the leaves so I don't have to worry about painting out of lines and having bits of shadow on the sky and elsewhere.
Before painting my shadows, however, I have to do a couple of things. I set the layer's blending mode to Multiply and adjust its opacity to about 65%. This ensures the detail in the leaves are not obscured by the color I'm about to apply.
Next I pick a medium warm gray. I want a fairly neutral gray so I don't tint the leaf colors too far from their original colors. Normally shadows are a cooler gray. But because leaves are semi-translucent some of their color will come through in the shadows. So, with all this orange and red in the leaves, I want to keep the shadows on the warm side here.
Next, I pick a soft brush and start painting here and there on the leaves that obviously are shadowed by nearby leaves. Then I go back and dab a few shadows on leaves necessarily look to be shadowed by a nearby leaf. There are a lot of other branches and leaves higher up in the tree and any leaf can have shadows cast from near or far.
Next I repeat the whole process to dab some shadows on the trees' trunks and branches. Here's a closeup detail of some leaf shadows. You can see the original detail remains here. It's now just a bit darker.
One thing to keep in mind when doing this. Don't precisely copy the shape of the above leaf in the shadow below. Just make rough approximations. Leaves are at varying distances, heights, and angles, and it's hard to see those relative distances in a flat 2D painting, so shadows don't always land as you'd expect. Keeping things more random gives it a more natural look.
OK, my next task is to add some more small twigs to make sure I don't have any leaves floating in mid air. Then I get to move on to the really fun part, detailing the deer! So look for these deer to have some fur texture in my next post. :)