RE: [APML] Provia concensus roundup

["Jon Kolb" <jkolb@datawest.net>]

Hi Herm,

I've been shooting Provia 400F 120 for over a year at f/4, f/5.6, f/6.4,
and f/7.9.  The blue response is excellent, and the red is very good,
but as expected a bit less than E200.  I'm planning to try some 35mm at
f/7.9 this winter.  Doing composites with E200 has been very successful,
but I really don't think it's needed on most subjects.

I have had some problems with uneven exposure, or what looks like
strange dark bands running across the slide on some, but not all shots
at f/7.9.  The cause of this has not been determined yet, and it could
be anything from wispy high clouds to some problem in handling the film
(I cut the paper backing out of the middle of a 120 roll to use it with
a vacuum back).  At this point I don't think it's the film itself, since
I've had many good shots with it over the last year.  I shot M31 at
f/7.9 and had this problem, so it's not posted.  The next step is to
start over and add one thing at a time (longer vs. shorter exposure,
push process, paper backing, vacuum back, etc.) to see where the problem
is coming from.  Nevertheless, I strongly recommend this film.

Here are samples at f/7.9:
http://home.datawest.net/jkolb/m45_tmb152.htm
http://home.datawest.net/jkolb/cocoon_tmb152.htm
http://home.datawest.net/jkolb/m24.htm

Here are samples at f/6.4, composited with E200 (and rather poorly
processed on the stars - I was trying something new at the time):
http://home.datawest.net/jkolb/ic405-410_epsilon.htm
http://home.datawest.net/jkolb/ic443_region.htm

Here are samples at f/5.6:
http://home.datawest.net/jkolb/cassiopeia.htm
http://home.datawest.net/jkolb/cygnus_milky_way.htm

Here are samples at f/4, composited with E200:
http://home.datawest.net/jkolb/antares_region.htm
http://home.datawest.net/jkolb/summerstarcloudsone.htm

I have also tried Provia 100F for deep sky, but it requires much longer
exposures and/or pushing, and there's really no advantage to it over
400F.  I also think the reds come out a bit ruddier than with 400F.
It's a great star trails film, though.

Sincerely,
Jon Kolb
Adventures in Astrophotography
http://home.datawest.net/jkolb/
jkolb@datawest.net






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