Vray Camera and exposure/grain question

[simmsimaging]

This might be a dumb question, but....

If I use the exposure function of the Vray camera to brighten up a render (which I'm doing unclamped) is the really functionally equivalent to increasing my light intensity, or is this just taking advantage of the HDR range to "cheat"? What I am really wondering if working this way is leaving me with more grain/artifacts in the shadows and less smooth light distributions etc.

Also - I know this has been asked before - but I really would like to be able to adjust the Vray camera focal point without shifting the view like it does now. I have read the argument that this is more "realistic" but i have never had a camera that jumps when you refocus like the Vray one does For that alone I use Max cameras most of the time, but I really miss the exposure controls when I do.

Thanks,
b

[Neilg]

i have never had a camera that jumps when you refocus like the Vray one does

What cameras have you used? Even my phone camera does this a little bit.

And i'm pretty sure it's basically like increasing the light intensity - think of it like a global multiplier for all the values.

[simmsimaging]

What cameras have you used? Even my phone camera does this a little bit.

Well, everything from a Nikon F-1 to Sinar 8X10's actually. I have worked in and around commercial photography for about 17 years now. Anyway, I literally meant "like" the Vray one does - as in 'similar to'. I know the image size shifts with real cameras but the Vray camera acts more like a zoom change than the scaling shift you get from focusing a lens, at least it appears that way to me. Regardless, I don't see the up-side of having this function built in - it's a pain in the ass in the real world too

b

[dlparisi]

If I use the exposure function of the Vray camera to brighten up a render (which I'm doing unclamped) is the really functionally equivalent to increasing my light intensity, or is this just taking advantage of the HDR range to "cheat"? What I am really wondering if working this way is leaving me with more grain/artifacts in the shadows and less smooth light distributions etc.

It's more or less equivalent to increasing the light intensities and you will not end up with more grain/noise/artifacts in the shadows. Vray's sampling is highly adaptive based on the noise that is (or would be) visible in the final rendering. You can test this out pretty easily by stopping down the camera a lot (or using a faster shutter/lower iso) so that the render comes out really dark. Becasue it's so dark it will render it out very fast. Then open up the camera to a point that's slightly overexposed and you'll see the scene take much longer to render due to all of the additional samples it'll have to take.

At least this is my understanding of it...

[simmsimaging]

At least this is my understanding of it...

That helps a lot - thanks for the explanation!

b