RE: [APML] OK, the film?

[Jon Kolb <jkolb@mindport.com>]

Bobby,

> Anybody else seeing wierd stuff on the old PPF?
> Jeff did you store it in the freezer of fridge?
> Bobby Middleton

Well, I'm not sure.  I've had to shoot around high clouds lately, and
honestly sometimes they get in the shot without my detecting them - it's
very high, very wispy stuff, and almost impossible to detect visually.  And,
I've noticed some unusually colorful sunsets lately, no doubt due to forest
fires west of my location, that may be playing tricks on me, too.  Despite
the high altitudes I get to work at, I don't think I've had a truly clear
night since March (not counting my adventure at Chiricahua in April).
September beckons - the best month of the year for clear, dry weather.

In any case, I was kind of avoiding posting this shot in order to see if I
could do any more with it, but since this PPF concern came up, I'm thinking
it might spur some useful commentary. This particular PPF120 expired in
November, and was in Russ Dickman's fridge before being carefully shipped
and put in mine about three months ago.  He lives in a really dry place, and
when I got this shipment it was really dry here as well (timing is
everything in the Rockies when it comes to moisture).  I've got about 80
more rolls of this stuff (most with expiration dates this year - April or
June, I believe) in airtight bags, inside of airtight containers, in my
freezer, and I've always assumed that the little foil pouches are airtight
as well.  

The whole issue of freezing film is actually irrelevant at this point - the
deed is done for my stockpile.  Thus, let's just look at the image and see
if there's anything going on here that can be pinned on freezing and not on
atmospheric conditions - it may be impossible to discern at this resolution,
but it doesn't hurt to have a look.  I know what I'm seeing (at full
resolution, and not counting the mechanical issues I seem to be profoundly
adept at) that's a concern, but for now it's perhaps best if I don't clue
anyone in.  If no one else sees it, I'll try to find the time to post a more
explicit image.

This is a 60 minute exposure at f/6.4 with the Borg 100ED, and based on
previous efforts, I'd say it was overexposed for the conditions.  I think
I've settled on 45 minutes at f/6.4 for unhypered PPF120, at least the batch
I've been using.  I will say that I think E200 120 is far less grainy than
PPF 120, but the PPF records blue so much better (in my brief experience)
that it was worth it to me to get my hands on some of it.  It's clear from
these early experiences that I'll have to stack PPF shots to get acceptable
grain, but that's tomorrow's problem. 

Anyway, here's the shot, so let's hear any comments - especially any that
may be film-related: http://home.datawest.net/jkolb/m52_region.htm

Here's another one from the same session, but later in the night.  I can see
in the full res image the same concern, but the whole thing also looks a lot
softer to me, possibly indicating the need to refocus the scope by this time
(coaching on Monday as usual), or due to more high haze.  This one is 50
minutes, and was much easier to deal with after scanning, even though I'm
not particularly happy with it yet:
http://home.datawest.net/jkolb/gamma_cygni_region.htm

These were scanned at 2750 DPI on the SS120 - I still haven't beefed up my
computer's memory enough to scan 120 film at 4000 DPI and have reasonable
response times when processing the files.  

If there's one comment that can be made about 120 film, it's that it either
blows you away with detail, or blows you off with your own mistakes.  It's
truly an illuminating format.  A hypering kit is on the way, the Epsilon
keeps calling me back ("135, 135, I'm fast, I'm fast...", and the adventure
continues.  Nobody can ever accuse me of getting bored with this  endeavor.

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




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