[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
Re: [APML] Black Negs a new developement
Hi John, Scott and Matt
Matt- I mean the negs are black. If held to a halogen light you can almost
see where one frame ends. But you really gotta look hard.
Scott- I kept the film in the refrigerator, in the sealed bags with
desiccant as from Lumicon. Some of it was used when it was 1 month old some
6 months old. I was shooting the daylight half rolls to check my
development times and skills, then would shoot the other half at night. I
didn't use any purge or vacuum. I didn't think TP needed it for only 30-40
minute shots.
John- the light leaks could be the problem. But with 4 different cameras?
I used 2 different 6x7s, an om1 and a nikon f3. I can't imagine the air was
thick enough to ruin the film. I am in the far west suburbs of Chicago, on
each night I am sure we were in the 60% humidity range. Is that too high
without a purge?
Thanks to all who responded. I will let you guys know if I find anything.
Brian
----- Original Message -----
From: "John C. Mirtle" <jmirtle@shaw.ca>
To: <astro-photo@seds.org>
Sent: Monday, December 10, 2001 8:02 PM
Subject: Re: [APML] Black Negs a new developement
> Brian;
> Quite the mystery! There are really only 3 things that can darken the
film -
> hypering, humidity and light. I stopped buying Lumicon film about 10 years
ago
> because they couldn't supply consistently hypered film. With a standard 7
minute
> development some rolls came out with a nice light gray background, another
roll
> would come out almost black, right through the socket holes. If your
successful
> daytime shots came from the same roll as the hooped Ha shots, then that
isn't
> the problem.
> Tech pan sucks up moisture like a Babel fish sucks up brain wave
energy,
> darkening the film. However, this is usually uneven giving a 'mottled'
> appearance. For what you are describing you would have to be standing
under a
> spritzer bottle during the exposure! That leaves light, possibly from
inside the
> camera, but at a low enough level that it doesn't get picked up with
unhypered
> film. Are there any batteries in your camera? I am wondering if you are
having a
> problem similar to the Olympus OM2. After the shutter is open for 2
minutes a
> red splodge will start to grow from the center of the film, caused by the
camera
> itself. This will occur even if the electronics are turned off - the
batteries
> MUST be removed to prevent this problem. Any chance of something similar
with
> your camera?
> It would be interesting to cut off a control piece of film from the
roll you
> are about to use, just before you load the camera. This could at least
confirm
> or remove the film from the list of suspects. 30 to 60 minute shots at f4
with
> Ha should show little background darkening. You should be able to go for
at
> least 4 hours under a good sky. I shoot for 45 minutes at f1.5.
>
> John Mirtle
> Calgary, Ab. Canada
>
> ----- Original Message -----
> From: "Brian Sledz" <brianhome@email.msn.com>
> To: <astro-photo@seds.org>
> Sent: Monday, December 10, 2001 9:15 AM
> Subject: Re: [APML] Black Negs a new developement
>
>
> > Hello Again,
> > I seem to have no luck developing Lumicon hypered tech pan. I took 4
more
> > TP shots Saturday night, none came out. I have not had any astro shots
come
> > out. Four tries now and all sessions black negs. I am thinking I
should
> > only be going 4-6 mins in d19? I went 8 minutes on Saturday night and
all
> > black negs again.
> > I took daytime shots used the same developer for 8 minutes and the shots
> > came out.
> > At first I kept trying to blame something else, but it must be the
hypering
> > developing combo ain't a workin. These exposures Saturday were Halpha
> > filter, Pentax SDUF II @f4, 35mm TP 30-60 minutes.
> > Any tips?
> > thank very much
> > Brian
>
>
>
> -- APML Archives at <http://astro.umsystem.edu/apml/> ---
> Unsubscribe at <majordomo@seds.org>
>
-- APML Archives at <http://astro.umsystem.edu/apml/> ---
Unsubscribe at <majordomo@seds.org>