Quick exposure setting tip with Vray Phys Cam

V-Ray V-Ray Common Tutorials, Tips & Tricks
1

Hi all. I’ve been mooching of this forum for a couple of years and I thought it was about time for me to make a small contribution. I looked and wasn’t able to find a similar tip anywhere. My apologies if it’s a rerun.

I use this trick to quickly set up the camera exposure for all my scenes: Shutter Speed and Film Speed are inversely related so if you set them to the same number (i.e. 200) they cancel each other out and the only value you have to worry about is the f-stop. I use F10 through F16 on exterior scenes (dusk through noon) and F3 through F6 for interiors.

If you’re working with DOF or motion blur than this obviously isn’t going to work for you. If not, then this means exposure adjustments are controlled through one setting and the process is quick and painless.

Hope this helps somebody and thanks to all the regulars for all the help you’ve given me!

Yan

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i tend to use larger apertures, are you using gamma corrected Linear Workflow?

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So, let me get this straight…
You’d set the ISO and Shutterspeed to 200, and then ONLY use the Fnumber to control the lightness of your image?

I “think” I’m using gamma corrected LWF…
Gamma and LUT are enabled
Input is set to 2.2
Output is set to 1.0
Gamma under Colormapping is set to 2.2
Is that right?

4

yep, those are the LWF settings i use.

since i rarely use motion blur or DOF i leave my camera ISO and shutter at default settings and also only adjust the aperture.

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nvanherpt: I’m using the version of linear workflow described by DrJan below. Along with that, I use Linear or Reinhard color mapping.

DrJan: exactly right, you set ISO and shutter to 200 (or any number) and only use F number to control the exposure or brightness.

I use the same linear workflow you do. “Affect color selectors” and “affect material editor” are also checked.

here’s what gave me the idea: http://en.wikipedia.org/wiki/Sunny\_16\_rule

hope this helps!

6

Ah, that’s nice. Thanks for the heads up!