Posted Sep.30th, 2012, viewed 76 times
Starting from the back and working forwards... Your blacks appear to be reasonably solid and dark, even on my monitor, so they correctly read as holes leading through to a barn with an absence of light. A black hole has no content and that's what the viewer expects to see. This whole exercise is essentially built around supplying visual clues that conform to the viewers expectations.
The gaps between your boards are very interesting. I'm quite certain you were seeing them as gaps and not just dark lines you had to shade, which is just as it should be.
Your wood is good, although it is rather light (in real life I suspect the right-hand side is as dark as the left). Darker wood would have given you a much wider palette of tones to use for the leaves. It looks as though you have layered the entire area with 2H or similar, and that always works well. It ties everything together and removes all traces of white, so any highlights in your leaves read as highlights. Your wood has very little detail, yet it is still undeniably wood - perfect for a secondary element in a drawing. Your nail heads are nicely underplayed too.
Your leaves work very well. They would have had even more three-dimensional form if you had not been forced to draw them with such light tones. They are quite realistic, but I think you could have added more shading to them so the three-dimensional form was better described.
Finally, I'm pleased to see you incorporating cast shadows on the wood, but they suggest that every leaf is virtually flat to the wall. Whenever a leaf curls away from the wall, it casts its shadow further away from itself. See below for an illustration. In general use, you don't need to include every shadow but those you do include should be used to increase the sense of depth and three-dimensionality. We're back to those visual clues again, and cast shadows are excellent devices to use.
However, if the leaves are casting shadows on the wall they must also be casting shadows on each other. With two exceptions, you haven't included any at all. Those cast shadows will play three roles: they'll visually divide one leaf from the other, creating depth; they'll define the edge of the foreground leaf allowing the eye to follow the leaf throughout its length; and they can be used to describe the three-dimensional form of the leaf that the shadow is falling on. See image below.
In response to image: