locking actual physical camera settings

Hi everyone! This is first post, sorry if i sound too much like a newb.:)

I was just wondering if there is a script that makes the VrayPhysicalCamera behave like an actual physical camera, warts and all? im studying photography at the moment, and what i mean is real cameras have discrete (albeit customizable) f-stops, shutterspeeds and iso's..

so what im saying is, i think if the rollout settings on the vrayphysicalcam can somehow be locked (if you want to) to go from, say, f/1.4 -> 2.0 -> 2.8 and shutterspeeds at 1/8 -> 1/15 -> 1/30 sec., etc.

while this might seem limiting, it has its merits:
1. it makes sense to someone who is used to using an slr, and gives you a real feel (from experience) if your environment lighting are in a real range, and not physically impossible(?)
2. those that havent used a camera will have an idea of how light is actually controlled in photography (halving and doubling of aperture opening area, shutterspeed, etc)
3. it makes the vrayphysicalcamera feel more "real", maybe even import settings for a real camera body, like a d700:) and of course you can unlock it as you wish.

sorry if it took too long to explain! not a scripter, but im sure its easy enough to do, hehe.. tried to look.. maybe a similar one has been done?

thanks!