Vray Physical Camera - Friend or Foe?

Do you want to create a camera that simulates a real world camera? Do you want to do specky renders with fancy vignetting, dof, and motion blur? Do you like waiting 20 hours for a single 1024×576 frame to render?

Meet the VRay Physical Camera.

In brief, The VRay Physical Camera allows you to use real-world parameters to set up the virtual CG camera (e.g. f-stop, lens focal length etc). -yes, this paragraph is stolen from the VRay help.

I decided I would waste some company time and see what this camera was like. In a simple scene, combined with the VRay sun it produced very nice results, I could almost feel the warmth radiating from the image.

Since this was all good, I decided to light and render a scene we’d been working on using the same techniques. Tragedy struck when I found out some frames were taking over 20 hours each to render. Granted that my scene did have fairly severe dof, lots of refracting-ness, sss, 6 vray lights and was very dark, but I just wasn’t expecting render times like that. I worked out that the depth of field was the main killer.

I was able to reduce the render time of most frames to 4 hours each, this was achieved by lowering the sampling of the dof and then upping the samples overall the whole image using the global multiplier spinner. I also switched from Adaptive subdivision image sampling to Adaptive DMC. Although with adaptive dmc the buckets are slowish on the blurry effects, it just churns through the image where there is alot of nothing.
The end results are not quite as smooth as the original and may need to be increased and re-rendered down the track, but for now it is fine.

I am still on the fence regarding the physical camera, although the render results are nice, it seems to bring a whole world of pain with it. Perhaps as I use it more I will begin to learn how to optimise and tweak it a little better. But we will see…