[APML] Kodak response --- more input needed

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

Hi Group:
As you may recall, I got tired of all the negotiating about the "petition"
to Kodak and sent in some letters ---over my own name only--- to some of the
people on Jon Kolb's list. Two days ago I got a very nice reply from one
person and have had two more e-mail interactions with this representative.
He is knowledgable about the films and their spectral characteristics. For
example, he says about the lack of good nebular response for Portra:

> Thank you for your reply.  The short red spectral sensitivity of Portra
> films is likely the issue.  Do you have practical experience using Kodak
> Portra 800 speed film?  The spectral sensitivity of this film is long red
> but I do not have data on its performance for extremely long exposures.
> Portra 800 does not have the same dopant  as Portra 400 film so
> reciprocity performance may not be as good as Portra 400.


He is now asking for more information about our experience with color
sensitivity (especially at the H-alpha end of the spectrum) and reciprocity.
He would rather not be overwhelmed with messages from APMLers at this point
but I can pass on any pertinent experience to him if you want to send it to
me. In particular, I think "real experience" data  with long exposures on
any Portra films, especially 800, and any Supra films, would be useful. I've
never used either Portra 800 or Supra 800, so I can't provide any data. I
know that Supra 400 works pretty well unhypered and I've never used Royal
Gold hypered. Based on Tony Hallas' experience with RG hypered, I guess it's
safe to say that that film is a definite keeper, but which others,
especially unhypered?

Thanks for your input....

Bert

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




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