RE: anti-newton ring glass

Newton's Rings are ring like optical artifacts that can occur when
optical surfaces are placed very close together. I find it happens most
with the base side of the film (shinny side) is sandwiched next to plain
glass and it can happen more in a humid environment. Thats why I like my
home made carrier because it keeps the film away from the glass. Most
scanners have enough depth of field to accommodate this.

Chris

--
Pinhole Blender
chris@pinholeblender.com
http://www.pinholeblender.com
> -------- Original Message --------
> Subject: RE: [pinhole-discussion] anti-newton ring glass
> From: "Doug Holt" <mancer@verizon.net>
> Date: Thu, December 09, 2004 11:27 am
> To: pinhole-discussion@spitbite.org
>
> Hmmm...  I've always used glass with problem transparencies to correct scan
> problems.  There may be an issue using Plexiglass as Acrylic has a different
> refraction index than glass.  Also, Plexiglass can be affected by even low
> heat from your scanner and may 'warp' just a little.
>
> No use my speculating though.  In this case, I'm sure your new home-made
> matboard holder will work.
>
>
> -----Original Message-----
> From: owner-pinhole-discussion@spitbite.org
> [mailto:owner-pinhole-discussion@spitbite.org] On Behalf Of Traci Bunkers
> Sent: Thursday, December 09, 2004 10:57 AM
> To: pinhole-discussion@spitbite.org
> Subject: Re: [pinhole-discussion] anti-newton ring glass
>
> Hi Doug,
> I tried that, actually with plexiglass, and that's when I got the
> rings. I don't know that using glass instead of plexiglass would make a
> difference.
> Traci Bunkers
> Bonkers Handmade Originals
> Tub Legs Zinestress
> http://www.bonkersfiber.com
>
>
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