[pure-silver] Re: filter factor


----- Original Message ----- From: "Ralph W. Lambrecht" <info@xxxxxxxxxxxxxxxx>
To: "PureSilverNew" <pure-silver@xxxxxxxxxxxxx>
Sent: Friday, September 29, 2006 2:10 PM
Subject: [pure-silver] Re: filter factor


Richard is right that the filter factor depends on the 'color' being
photographed. A contrast-enhancing filter would not work as intended if it
would have the same filter factor for all colors, it would just be a neutral
density filter.

Nevertheless, assuming the aim is ONE average filter factor, the method
proposed by Dave works well. To see the effect and the filter factor, one
can photograph something like the Kodak Color Separation Guide and Gray
Scale with and without the filter. It will tell you the effect of the filter
on each color and the average gray. The resulting filter factor works for
all average cases.





Regards



Ralph W. Lambrecht

http://www.darkroomagic.com
Kodak used to publish photos of this sort in its little filter handbooks. They are very interesting and a good idea. Its also useful to photograph something like printed cloth to see what the rendering is.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx 

=============================================================================================================
To unsubscribe from this list, go to www.freelists.org and logon to your 
account (the same e-mail address and password you set-up when you subscribed,) 
and unsubscribe from there.

Other related posts: