First of all, they all look pretty nice. The one that I think needs the most work, though, is the ETB. I haven't seen an ETB (except momentarily at expos, I think...) but the head looks great. The problem is that the rest of the body/picture is very indistinguishable and flat. With the detail on the head I think a little more care should have been done on the body.
I love the ball python. It looks darker than the picture on your computer, but that could easily be because of the lighting. It also seems to go between 3D and 2D. The head is 3D, the neck next to rest of the body switches to 2D, and the rest is more 3D.
The bunny is cute, and I don't have much on it. It is a little farther from realism as the first two, which based on the three seems to be your stronger suit. The only thing I can really see on it in the right (by our view) side of its face looks a little long/awkward.
And like others have said, you could work a little on the shadows. Not the easiest thing to learn, but it will really make your artwork pop when you figure it out.
It might have simply been the pastels which held you back. Your pencil (pen?) drawings are amazing. At the same time, though, I would suggest doing more with pastels because it will look a lot better if you can work with multiple mediums.
P.S. that wolf and tiger are AMAZING!
Reply With Quote