Minimizing Moire patterns when scanning large format negat..

Terry Smith wrote:
> I'm a large format photographer using an Epson 4870 scanner to scan my 5x7
> negatives. I've had a custom 5x7 carrier made to hold the negatives (similar
> to the 4x5 transparency carrier that came with the scanner). In general,
> this setup work quite well, but I'm getting moiré patterns, especially in
> the middle of the negatives where there is a lot of single tonality area
> (like open sky) mostly on B&W negatives.
>
> Does anyone have a clue on how to minimize this moiré pattern problem? (and
> no, I'd rather not send my negs out to be drum scanned... <s>)
>
> Thanks,
> Terry

Focal Point Introduces Anti-Newton Ring Glass For Scaners

March 17, 2006
PRESS RELEASE


Focal Point Introduces Anti-Newton Ring Glass for Scanners

Focal Point, the foremost supplier of Anti-Newton Ring glass to the
photographic industry announces introduction of their line of products
designed especially for scanners. "After sixteen years of solving the
Newton ring problem for photolabs, we're bringing our technology to
the digital age." Says Michael Sparks, President of Focal Point.

Newton rings, those "oil on water" looking optical effects occur
when two smooth surfaces like glass and film are sandwiched together.
Frequently small "pockets" of air are trapped between these
materials. As light passed through this void it's refracted causing a
Newton ring. Focal Points Anti-Newton Ring glass is specially designed
to eliminate these image ruining problems without effecting the quality
of your scan.

Newton Rings are difficult to retouch out of an image, and image
correcting software can have problems distinguishing them from the
image itself. Many scanner owners have found that eliminating the
Newton rings prior to scanning makes for a higher quality image.

Focal Point specializes in eliminating the Newton ring problem. We work
with our clients (amateurs, professionals, and manufacturers) to make
their scanners Newton ring free. Our solutions range from the
simplicity of replacing plain scanner glass with our Anti-Newton Glass
to custom modification or construction of film holders.

For More Information Contact
Michael Sparks, Focal Point, 3129 Canterbury St., Deltona, FL. 32738
386-860-3918, mike.RemoveThis@fpointinc.com
PRESS RELEASE

In article <e4tfvn$rn9$1@nnrp.gol.com>,
David J. Littleboy <davidjl.DeleteThis@gol.com> wrote:

>The Epson flatbed's don't focus. You need to test for optimal focus, and
>hold the film at that distance above the glass. The new V700 (or V750)
>provides means for doing that.

My 4870 has film holders that keep the film off the glass.