Re: [APML] Fuji 800 4-layer

["Lydia Rufleth" <e.i.rufleth@SNET.Net>]

Hi Robert,

Thanks for filling me in on the Fuji 4th layer film. It sounds like it will
be OK at my novice level. I have a long way to go before I will be
photographing emission nebulae.

 I hope to shoot the Geminids with the Fuji 800 Xtra. I am fascinated with
your 8-camera equatorial platform &  am working on a 3-camera platform to
put on my equatorial mount.

Regards,
Lydia

-----Original Message-----
From: Robert Reeves <reeves10@swbell.net>
To: astro-photo@seds.org <astro-photo@seds.org>
Date: Saturday, December 08, 2001 4:48 PM
Subject: Re: [APML] Fuji 800 4-layer


> I ordered some Fujicolor Superia 800 after reading that many of you were
> going to use it for the Leonids. What I got was the Fuji 800 Xtra. From
your
> letters it sounds like this is a completely different film.  Is this a
poor
> film for astrophotography?
>
> Lydia

Hi Lydia,

To bring you up to speed on this film situation, the problem with the Fuji
"4th layer" films is that fourth layer robs the film of its extended red
sensitivity.  Fuji did this to make the film produce images more atune to
the real world.  The previous generation of Superia films (pre-4th layer)
were quite sensitive to red wavelengths at the extreme end of human visual
sensitivity.  This was great for astrophotography because those far red
wavelengths are where the red H-Alpha emision is in celestial nebulae.  But
at the same time, this extra red sensitivity make people look too pink.  Now
that the Superia films are less red sensitive, they make people look more
normal, but they don't record the important H-Alpha emisions as well as they
did before.

But the H-Alpha is just one region where we do astrophotogrtaphy.  The 4th
layer Superia films still do well for star trails, meteors,  Earth
satellites, zodiacal light, planetary nebulae (which are more greenish),
galaxies (which are more bluish), or any target where we don't need all the
red sensitivity we can get.

So don't fret about getting Superia X-tra.  You just have to match the film
to the target.  It will be pretty descent film for the Geminid meteors later
this month if you are up to early AM shooting.

Robert Reeves                      reeves10@swbell.net
520 Rittiman Rd.                   www.robertreeves.com
San Antonio, Texas 78209    210-828-9036
USA                                     29.484  98.440  200 meters


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