Re: CCD/noise in scanners was RE: [APML] new image: IC1396-Provia and halpha CCD

[George Anderson <georgea@cam.org>]

The older Sprintscan 35 uses a four or five inch flourescent tube. The
heat produced is minimal and there is a very small cooling fan in the
back of the unit.

George Anderson
Montreal Canada

Clear skies and good health 

> Jim Collier wrote:
> 
> Jerry, I don't know what kind of light the sprintscan uses.  It has a
> distinctive blue tint whatever it is...maybe LED.  For whatever
> reason, it does get very hot in there on long scans.  The warping I
> was referring to is actually two types, which I didn't elaborate on.
> 1) warping from the drying process [hung straight, warped on the long
> axis] which is what flattening in books fixes nicely, and 2) warping
> in a "bubble" under the heat of the scanner.
> 
> Jim
> 
> -----Original Message-----
> From: owner-astro-photo@seds.org [mailto:owner-astro-photo@seds.org]
> On Behalf Of Jerry Lodriguss
> Sent: Friday, October 11, 2002 2:29 PM
> To: astro-photo@seds.org
> Subject: RE: CCD/noise in scanners was RE: [APML] new image:
> IC1396-Provia and halpha CCD
> 
> At 11:18 AM 10/11/2002 -0500, you wrote:
> >Another point about the scanner light being on for a long time is it
> >tends
> >to warp the negative, making the scan blurry.  At least on my scanner
> >(Polaroid sprintscan).  Haven't found a solution to this other than
> to
> >store the negatives in a book for days prior.  I've also though about
> >having a fan blow through the scanner (bad for dust tough).
> 
> Heat will definitely warp film, but doesn't the Polaroid Sprintscan
> use a
> cathode tube as a light source, which doesn't put out any heat?
> 
> If the solution is that you have to put them in a book to flatten them
> prior to the scan, then the cause of the curling is not from the
> scanner.
> 
> Try not drying the film on the reel after you develop it. Hang it
> straight.
> 
> Jerry
> 
> Astronomical photography: http://www.astropix.com
> 
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