There is nothing to comment on (being that it's all pretty much perfect) except the DOF>
General rule of thumb. If you get extreme depth of field it's due to getting CLOSE to an object, which implies immediately that it is a small object. The problem here, is that for a normal camera in normal lighting f1.0 would be impossible, that is without something like 16,000th of a second, or perhaps ISO12 film.
Something photographed with a low f-stop, which in my book is anything below f4 means low light. And low light photos have a distinctive look.
The reason the drill looks so small is that in order to reproduce your rendering with a real lense is to photograph a 4" drill with daylight levels of light, really close. also keep in mind that there is only one lense (that I know of) that actually has f1.0 (canon 50mm f1) Your much safer to stick to f4, since that's' the common f-stop for consumer zoom lenses. Maxwell is accurate enough that this in itself should self-regulate any unnatural looking DOF effects in your images. In fact, I would recommend not going below f8, which is what I try to do with all product photos.
Example of appropraite levels of DOF in an extreme closup:
http://www.iandavis.ws/display_image.asp?PictureID=516
Examples of a full frame object SMALLER then your drill:
http://www.iandavis.ws/display_image.asp?PictureID=525
Depth of field is somewhat of a pet peeve of mine. Being a photographer I know that extreme depth of field is something I (and most photographers) strive to avoid in average product shots. Depth of field is actually used to bring into focus (sorry for the pun) an area of the object, and exclude others. Or to knock out an ugly background from a subject you are photographing. We should NEVER see depth blur on larger objects like full frame car renders, or any product that doesn't break the edge of frame.
Depth blur IS appropriate for extreme closeups, but should be managed to include all important aspects of the object you are trying to 'photograph'
Sometimes it's not possible to avoid, but in my experience it's only been an issue when photographing insects or other such things which need to be shot that close to the lense (less then a foot). Objects 1-3 feet in size as a rule are completely in focus.
DOF effects are like fonts used to be during the desktop publishing revolution... Look I CAN use 30 fonts... so I will.. Now that DOF is possible and easy, EVERYONE is using it. It's just wrong. wrong wrong...
It's a good idea if there is any question, just find a photo and see how an object like yours IS photographed.
cheers
but that's a very descriptive and well formulated explanation. Interesting reading too