Re: [APML] Help with M8 on Tech Pan

["John C. Mirtle" <spampit@shaw.ca>]

Thom,
    Here comes the voodoo part. Tech pan is sensitive to over-agitation, but
it is also sensitive to under-agitation. To complicate matters, the
frequency of agitation depends on total development time. This has been an
ongoing debate since I joined the list, I would recommend that you find that
works for you and stick with it. When shooting at f6 and slower, there is a
lot of merit in processing for 10 minutes and longer, even in D19. Your
hypering must be flawless, the film must be kept perfectly dry (nitrogen
purge recommended) as you are pulling the max amount of detail from the
film. With HC110 this development time is normal, flaws in the film and
handling will not show as much as if it were processed in D19. When
developing this long, you don't need to agitate as often. Once per minute is
probably fine, unless you are seeing a darkening near the sprocket holes.
    With my Schmidt camera shots, I usually process between 4 and 6 minutes.
Over the last month I have done some experimenting of my own with agitation
times. Agitating once per minute produces problems for me, when processing
for this short a time. Once per minute produced a very dark rebate around
the sprocket holes, very much the same effect as over agitation! For me,
with the shorter times, agitating every 20 seconds looks best with D19.
Using HC110 is going to be a bit different, but I don't think that you will
be developing for anything under 8 minutes. I would stay with 1 minute
agitation for now, and get rid of the problems you have that are caused by
humidity. Once you have that under control, then have a close look at the
area near the sprocket holes to see if there is any evidence of over or
under agitation.

If this was easy, everyone would be doing it. :-)

John Mirtle
Calgary, Ab. Canada

----- Original Message ----- 
From: "Thom Iwancio" <tiwancio@sc.rr.com>
To: "'Discussion of Film Astrophotography'" <astro-photo@seds.org>
Sent: Sunday, September 21, 2003 8:39 AM
Subject: RE: [APML] Help with M8 on Tech Pan


Thanks Jerry, why is it the answer that makes the most sense is always
the one you don't want to hear.  Arrrgggg....

Short of the humidity concerns, hand processing is probably the thing
that has the most inconsistency to it for me.  I mix and control
temperature like it is a religion and try to do the same with the
agitation but you can't compare hand agitation with drum processing. The
drill for me is to:
1) pour
2) twist 3-4 times
3) tap
4) invert once (about one second over and one second back up)
5) invert once every minute thereafter (same speed as above)

What do you recommend I try differently?  Invert less often or more
slowly? Forget the twists?
BTW, development was 12 minutes, HC-110 dilution B @ 68 F.

Thanks again,

Thom Iwancio
Elgin, SC
www.machunter.org
home.sc.rr.com/thomiwancio

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