Implementing DOF in PyMol wouldn't be trivial and I'm not sure it's a priority/necessity. There are excellent open-source (and proprietary) rendering engines out there that can render better and faster than PyMol. Why re-invent the wheel... my 2 cents' worth :)
However, aside from exporting to PovRay, you can do DOF from PyMol ray-traced PNG's (32-bit, i.e. w/ alpha channel) in post-production using the alpha channel as a Z-depth channel. If there is interest, I don't mind writing up a tutorial, but note that it does involve other software aside from PyMol, such as Photoshop.
From: firstname.lastname@example.org on behalf of Thomas Blicher
Sent: Wed 5/23/2007 5:32 AM
Subject: [PyMOL] Focus depth
Dear PyMOL users,
I was wondering if it is possible to implement focus depth (also known as depth of field or DOF) in PyMOL. I have come across several links to DOF and it appears to be a common feature of ray-tracing programs. I imagine that it could work like the fog function – possibly in combination with this – to give an even more realistic feeling of depth/perspective, especially in close-ups. It is probably most useful for making artistic molecular graphics, i.e. for ray-traced images, so it wouldn’t have to work real-time.
Does anyone have ideas on how to implement this in PyMOL (other than exporting files and rendering them in POVRay)?