Re: umm (ortho-litho development)

Gord -

It also probably has a fair amount to do with the developer. Many developers
of this type will result in a lessened film speed. It's just the cost of doing
business.

Cheers -

george

--- "Gordon J. Holtslander" <holtsg@duke.usask.ca> wrote:
>
> Hi:
>
> It seems that rating the film at 1 ASA compensates for reciprocity. I'm
> not sure of the F-stop of the 12x18- its not my camera. We usually get a
> good estimate of the pinhole diamter using a loup and a fine ruler
> graduated in .5 mm From that we calculate the f-stop based on the focal
> length. We use a light-meter to get an exposure base.
>
> It gets good negatives from exposures in the range of 5 min to an hour.
> Never had an exposure of less than 5 minutes with this film and LC-1
>
> Gord
>
> On Mon, 4 Mar 2002, John Yeo wrote:
>
> >
> > > I use LC-1 and ortho film too. Its very good. However it is slow. An
> > ASA of 1. I've used a
> > > 12 X 18 camera. It ended up having an f stop in the range 0f 300. This
> > translates to an
> > > exposure of an hour on a bright sunny day for one picture.
> >
> > How does that work? For a sunny day exposure with ASA 1, you would have 1
> > sec @ f/16. f/360 is 9 stops away from f/16, so your exposure should be
> > about 8.5 min...
> >
> > Or is it because of reciprocity failure that you are getting exposures of
> an
> > hour?
> >
> > John
> >
> >
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>
> ---------------------------------------------------------
> Gordon J. Holtslander Dept. of Biology
> holtsg@duke.usask.ca 112 Science Place
> http://duke.usask.ca/~holtsg University of Saskatchewan
> Tel (306) 966-4433 Saskatoon, Saskatchewan
> Fax (306) 966-4461 Canada S7N 5E2
> ---------------------------------------------------------
>
>
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=====
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Received on Tue Mar 5 07:43:06 2002