vray camera / exposure / max camera question

[stevesideas]

I've often wondered but never asked. Assuming noise is the obvious difference between scenarios is there any other difference between having low light intensity with a vray camera adjusted to expose the scene correctly and having a light with high intensity and the vray camera adjusted for correct exposure ? Is there a difference between using the vray camera and standard max camera apart from the obvious lack of exposure and colour correction control ?Does a scene using a vray sun system and vray camera give a more physically correct result compared to using a standard camera with the sun intensity adjusted right down ?

Would the light act differently between scenes...would it bounce more ? Maybe obvious to some but without extensive testing I do not know myself as I use different setups for different projects.

[Zdravko]

The idea behind the high exposure of the VRayPhysicalCamera and the strong intensity of the VRaySun/Sky was to imitate real-world parameters. By working in this manner you have strong base from which you can create your physical correct images and get expected results similar to real life situations, which is crucial for some 3d artists.
Furthermore, camera effects like DOF and MB are physically correct due to the parameters "F-stop" and "Shutter speed" which are found in real life cameras.
After all it is up to the artist to decide whether this is the approach he want to use.

[Guest]

What I find is that once you have found your ideal f-stop value for DOF, you can adjust either the ISO or the shutter speed to bring it to the correct brightness. In the real world adjusting these two is needed to reduce noise but in a V-Ray camera noise does not exist therefore it doesn't matter which one you adjust. This can be confusing to some I imagine.

It would be great to introduce real world effects such as noise so that ISO and shutter speed can be used correctly. Or a smarter CGI way for adding DOF. I mentioned before about an interactive picker where by you just pick the area you want to focus on in the frame buffer and then adjust a slider to control the amount of blur. Then ISO and Shutter speed could be combined into one setting which is called exposure. This again could be a slider (much like Photoshop) where you adjust to suite your lighting (which are set up to be real world intensities such as IES). The DOF slider does not effect the exposure so you can simply adjust to taste.

In my experience no one cares what the camera settings are we just want good exposure and what looks right to the human eye on screen. Fair enough if you are camera matching it would be useful but certainly in my line of work my camera matching is about 10% of my yearly work compared to the 90% which is full CGI.

Just my two cents