Re: [APML] Another Hydrogen Alpha sensitive color film to consider...

["Bert Katzung" <katzung1@attbi.com>]

Hi Alan:
Yes, I agree --- the opinion on Supra 800 was pretty much all negative for
long exposure stuff. For auroras, meteors, etc, it was pretty good. The
problem with it (and i think Don Westergren was able to quantitate it with
his lab testing) is that the reciprocity failure for the different layers
varies tremendously with the 800 film whereas it is pretty constant (and
small) for the 400 stuff. As a result, the cyan layer was still going strong
in the 800 long after the other layers had given up --- thus giving me that
cyan M42. Unfortunately, neither Fuji nor Kodak quantitate reciprocity
failure out past ten seconds exposure. Pretty useless for our applications.
If Kodak says "not recommended for exposures longer than 10 seconds" (which
they do for some of their films) then you know the reciprocity failure must
be really bad!
Of course the new Max film that Chris is talking about may not have this
problem and turn out to be pretty good.
Bert

Bert Katzung
katzung1@attbi.com
www.astronomy-images.com

----- Original Message -----
From: "Alan Voetsch" <critter12952@yahoo.com>
To: "Discussion of Film Astrophotography" <astro-photo@seds.org>
Sent: Saturday, February 22, 2003 8:59 PM
Subject: Re: [APML] Another Hydrogen Alpha sensitive color film to
consider...


> Hey Bert and Joe,
>
> --- Bert Katzung <katzung1@attbi.com> wrote:
> > Hi Folks:
> > I posted a quick-'n-dirty test of Supra 800 (compared with
> >E200/Elite200) some time ago
> > http://www.astronomy-images.com/Tests/test-of-kodak-Supra800-film.htm
> > and Pat Freeman has similar results on his webpage.
> > ----- Original Message -----
> > From: "Joe Pedit" <pedit@email.unc.edu>
> > > Kodak Max Versatility Plus 800 has the same spectral sensitivity
> > curves
> > > as Supra 800.  See:
>
<http://www.kodak.com/global/en/professional/support/techPubs/e2519/f009_033
> > 2ac.gif>
> > > There was an APML discussion about Supra 800 a few months ago and
> > the
> > > results were mixed.
>
> I don't think they were mixed, I don't recall hearing anything good
> about Supra800. I wonder though, if there is any way to tell from
> looking at the stat sheets, if this film will stay strong or if it
> peters out. I have to ask because the 400 version is SO strong that it
> seems like a little something would rub off on the faster version.
> Maybe they're not related after all.
>
> Alan
>
> =====
> Alan Voetsch
> critter12952@yahoo.com
>
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