[pure-silver] Re: Slightly OT: Lens Scratches
- From: Jim Brick <jim@xxxxxxxxx>
- To: pure-silver@xxxxxxxxxxxxx
- Date: Wed, 17 Nov 2004 09:36:50 -0800
At 07:00 AM 11/17/2004, Eric Maquiling wrote:
>On 11/16 22:19, Jim Brick wrote:
> > You can put some blackening (I forget what folks use) in the scratches
> > which will help reduce any light scattering caused by the scratches.
> Carbon
> > black? India ink? ???
>
>Sharpies? Not sure either but I think I heard people say they use
>that. Comes
>is fine, extra-fine points.
>
>--
>Eric
The following is from Peter Rosenthal, camera repair person in Flagstaff AZ:
"The main point of filling the scratch is to prevent light from passing
through the scratch and thereby (I sincerely apologize for using the word
thereby) preventing lots of light scatter. Well not lots, but some. You have
to use BLACK paint or crayon. Try to use the absolute minimum, just enough
to fill it. Any more than that and you risk making a shadow of it on the
film. Also...if it is too large a spot, diffraction around it's larger edge
will cause scattering of it's own. As hokey as it sounds, it's a cheap and
effective way of preventing excessive lowering of the MTF of your lens.
g'luck!!"
Peter
--
Peter Rosenthal
PR Camera Repair
111 E. Aspen #1
Flagstaff, AZ 86001
928 779-5263
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