What gamma should be used for scanned photos?

Zebra wrote on 7/11/2001, 7:53 AM

My HP5370C scanner defaults to a gamma (midtone) setting of 2.2. Tests seem to indicate that during rendering, VF applies a further gamma correction to stills resulting in too bright, washed-out video. What scanner gamma settings have other users employed? I now have scanner files with a gamma of 2.2 for genealogy photos that I no longer have access to. Does anyone know what gamma equation is used by VF for stills so that I can apply the inverse transform to my existing files?

Comments

wvg wrote on 7/11/2001, 10:56 AM

Gamma is relative brightness of an image and there is also an interaction between the primary colors displayed on a computer monitor. The settings are differnet depending if you are on the Windows platform or on a Mac which explains why images created on one platform may look washed out or too dark on the other.

If you do a lot of scanning, you should calibrate your scanner and monitor to avoid introducing differences. For a more detailed discussion of gamma visit this site:

http://www.cgsd.com/papers/gamma_intro.html

Your best bet from within Video Factory would be to use the HSL filter. Just a little tweaking can make a big difference.