Re: Re: extremely long exposures

----- Original Message -----
From: "Stephen Harris" <smhcine@email.com>
To: <pinhole-discussion@pinhole.com>
Sent: Saturday, January 06, 2001 9:54 AM
Subject: [pinhole-discussion] Re: extremely long exposures

> > Stephen,
> > Tell us what film you intend to use and we may be able
to
> > help you.

> Guillermo, I'm using Fuji 400 ASA Portra Neg in 120 roll film.

Color film, eh? Unfortunately I have no experience with that kind of
material.

Let's see if this can help you, taking the exposures indicated by Fuji for
"long exposures", if I try to find an equation that "fit" a polynomial curve
joining those exposures, a little program I have came up with this:

Corrected Time = (4.44 x Time x Time) + (1.311 x Time) - 3.55
(Time should be expressed in seconds)

For example for 5 minutes = 300 seconds the corrected time would be:

Corrected Time = (4.44 x 300) + (1.311 x 300) - 3.55
Corrected Time = 1722 seconds or about 28 minutes and 42 seconds

Let us know if you give it a try.

Guillermo
Received on Sat Jan 6 19:48:36 2001