Re: [APML] NHG-II 800

["John Boudreau" <jeboud@attbi.com>]

----- Original Message -----
From: "Stan Richard" <stanrichard@hotmail.com>
To: <astro-photo@seds.org>
Sent: Wednesday, March 06, 2002 12:07 PM
Subject: Re: [APML] NHG-II 800


> Chris, maybe I don't know what I'm talking about and I don't do long
> exposure astrophotography with a telescope but the NPZ 800 Pro seems to
have
> pretty good red and blue response.  Check out the aurora pics I used it
for:
>
> http://www.geocities.com/stanzman_2001/Aurora102801.html
>
> Stan Richard



Hi Stan--

I've only seen the spectral response chart for the "4th layer" Fuji Superia
X-TRA 800, but it's fairly consistent with the newer Kodak Portra films
(except Portra 800) as far as red response goes. That is, where the earlier
Fuji 800 film had peak red sensitivity at 650nm, the new film's red peak is
around 620 to 630nm, and the sensitivity curve starts dropping off
noticeably before the 656nm line where much of our emission nebula really
show up.

Apparently Fuji hasn't made the NPZ spectral sensitivity chart available
yet, so until then this is only a best guess on my part and assumes that
Fuji NPZ has similar spectral curves as X-TRA 800:
Since auroral reds are emitted about 630nm, they are right in the prime peak
of these new films, and should show up quite well. In fact the new films
*may* actually be better than the older versions at recording auroral reds.

However any testing of Fuji "4th layer" films that I've seen so far are very
poor at emission nebula reds, if fact they are virtually blind there. Only
time will tell what Fuji NPZ can really do--- I hope Fuji has extended it's
sensitivity curve beyond what they've done with their other new color
negative films.

John Boudreau
jeboud@attbi.com
http://home.attbi.com/~jeboud/astro.htm


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