On Mon, 16 Aug 2004 "Craig Brougher" <craigbr@...>
said:

> I am wondering-- what would happen to your sig/noise ratio if
> you were to "filter" your light source? If the paper is brown
> then there's a lot of yellow in the light. Just a thought.

Thank you for your suggestion of this vexing problem. A few
of these very old 58n rolls do not have inconsistent opacity
throughout their length. Portions of it are quite thin
translucent, while other portions are quite opaque.

I do filter my light source through 2 layers of neutral density
filter, plus driving my CCFL lamp at 9vdc instead of its normal
12vdc. This combination has worked well for 1,800 scans, but
these rolls are adding a new dimension, fortunately few.

In theory, all I need to do is set exposure for the translucent
portion of the roll. However, for whatever reason, these few
old rolls do suffer from far more random blooms than other rolls
I've passed through my scanner.

My major shortcoming is zero knowledge of electronics and
programming. I'm very dependent on the kindness and
generosity of other more knowledgeable people within this group.
I thought I would relate this experience in the event that other
people following in my footsteps may have a solution.

Regards,

Terry


Terry Smythe 204-832-3982 (land line)
55 Rowand Avenue 204-981-3229 (cell)
Winnipeg, MB, Canada R3J 2N6 smythe@...
Preserving our Musical Heritage
http://members.shaw.ca/smythe/rebirth.htm