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Re: [APML] question on exposure times for E200

Hi Richard,

>From my experience, under a dark sky I would go for 60 - 90 minutes with
your focal ratio and E200 push processed two stops.

You don't have to do anything special if you push-process your film, except
asking the processing staff to do so (it consists in increasing a bit the
first developer time). However, if you are going to use the same roll for
daylight normal shots, remember to adjust your camera's shutter to ISO 640
if you push E200 two stops; to ISO 320 if you push one stop. By pushing E200
two stops, the grain increment is negligible, and the sky background gets
bright enough to make the scanning process much easier without losing really
faint stuff.

This is IMHO, of course. Good luck and clear sky!

Juan
-- 
-------------------------------------------------
Juan Conejero, Pleiades Astrophoto
juan.conejero_at_pleiades-astrophoto.com
http://pleiades-astrophoto.com/
-------------------------------------------------

----- Original Message ----- 
From: "Richard Crisp" <rdcrisp@earthlink.net>
To: "Stuart Heggie" <stuart.j.heggie@sympatico.ca>; "Discussion of Film
Astrophotography" <astro-photo@seds.org>
Sent: Saturday, July 10, 2004 9:30 PM
Subject: Re: [APML] question on exposure times for E200


thanks Stuart.

I guess I have to ask the film processing people to push it one stop, right?
That's not an exposure parameter from what I remember, it is a processing
parameter, right?

I wonder if I will have fogging problems going so long?


  ----- Original Message ----- 
  From: Stuart Heggie
  To: Richard Crisp ; Discussion of Film Astrophotography
  Sent: Saturday, July 10, 2004 12:13 PM
  Subject: Re: [APML] question on exposure times for E200


  Richard, you could go 2 hours with that film f-ratio combo. I go 40 min at
f/4 with 400 speed film from my rural skies. My math says the square of your
f-ratio divided by mine * 40 min is about 2 hours so if you push the E200
one stop you get 2 hours. You could probably get away with less but I bet
that would work.

  Beauty in things exists in the mind that contemplates them.

  Stuart
  http://www3.sympatico.ca/stuart.j.heggie/Stuart.J.Heggie/
  Flesherton, Ontario, Canada

    ----- Original Message ----- 
    From: Richard Crisp
    To: Discussion of Film Astrophotography
    Sent: Saturday, July 10, 2004 3:03 PM
    Subject: [APML] question on exposure times for E200


    Hi gang

    I want to do some prime focus film shots tonight in the Saggittarius
region using my Pentax 6x7 and some E200 film.

    I am really excited about doing this.

    I want to mount the camera on my AP180EDT with both the 0.75x
telecompressor and the AP field flattener. That gives a focal ratio of
f/6.75

    My question is what exposure time should I use for something like M20?

    If I got no answers from the list, I'd probably go with 45 minutes, but
you folks are the experts, so I'd like to hear some other opinions.

    Thanks and best regards
    Richard




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