Luminous Landscape Forum

Site & Board Matters => Luminous Landscape Video => Topic started by: Wayne194 on April 24, 2008, 05:51:53 pm

Title: Camera Calibration?
Post by: Wayne194 on April 24, 2008, 05:51:53 pm

When photographing the color checker, should I use auto white balance or set the camera to sunshine if outside or flour. if inside with flour. lighting?
I used auto for the first calibration and the results are really better.

Thanks
Wayne

Title: Camera Calibration?
Post by: Frank Doorhof on April 24, 2008, 06:10:21 pm

Hi,
Use RAW files and set the whitebalance with the graypatch on the colorchecker.

Title: Camera Calibration?
Post by: Wayne194 on April 24, 2008, 08:15:02 pm

Thanks Frank,

That is exactly what I did.

Wayne

Title: Camera Calibration?
Post by: sojournerphoto on April 24, 2008, 08:20:06 pm

Quote

When photographing the color checker, should I use auto white balance or set the camera to sunshine if outside or flour. if inside with flour. lighting?
I used auto for the first calibration and the results are really better.

Thanks
Wayne
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Just a thought, but you might get better results using sunlight than flourescent - the spectrums is a lot cleaner, making the wb easier to get right and more meaningful

Mike

Title: Camera Calibration?
Post by: Frank Doorhof on April 25, 2008, 02:31:35 am

Mike,
When you shoot RAW (what you should) the setting of WB is not important (unless you want the preview on your LCD to be correct).

Title: Camera Calibration?
Post by: sojournerphoto on April 25, 2008, 07:13:10 am

Quote

Mike,
When you shoot RAW (what you should) the setting of WB is not important (unless you want the preview on your LCD to be correct).
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Hi Frank

Yes, I appreciate this. I was just thinking aloud that when shooting the colour checker (unless you are recalibrating for each shoot - which may be useful for your workflow, but isn't my approach) it is probably worthwhile trying to maximise the data in each colour channel. Fluorescents usually have a spike in the green part of the spectrum requiring that the green channel is pulled down during rendering. In terms of exposure this means the r and b channels will get relatively less exposure if the green isn't to be clipped, and so have less data to work with.

Simon Tindeman's script allows a starting estimate of D50 or D65 for WB, and I think the suppporting documentation suggests that these are preferred unless you do a lot of shooting in other conditions.

Cheers

Mike