Re: Multiple Pinholes

> ----- Original Message -----
> From: Temi <Temi@TemiOriginals.com>
>> Would it be best to come up with a total opening and figure time from
>> this or to figure time for one pinhole and then divide this by the
>> number of pinholes used.

----- Original Message -----
From: "William Erickson" <erickson@ic.mankato.mn.us>
> My experience was that adding up the areas of the multiple pinholes,
> dividing that into the area of an f22 aperture at the pinhole-film
> distance being used, and multiplying the metered f22 time by the
> product of the division works fine.

The above 3 seemingly different approaches (2 by Temi, 1 by William) are in
fact the same thing. They are based, even if it doesn't look like that, in
finding the exposure time needed for an aperture equivalent to a pinhole
with an area equal to the combined areas of all pinholes being used.

I'd say that if the pinholes are very close, the above approaches could be
the right ones, but the more pinholes we used at once and the more they are
separated from each other, increases the need for greater exposure time that
the one dictated by the 3 mentioned approaches. Some other factors
requiring consideration are: focal length of the camera and shape of the
film plane, whether all pinholes are the same size, equidistant, etc.

Yes, I know, I am not given any suggestion, so far!

I believe is difficult to suggest a method that works for all cases. My
suggestion, find the exposure time using any of the above 3 methods (result
would be the same, anyway) and then increase the exposure time by 1 stop
and do some trial and errors.

Guillermo
Received on Sun Mar 25 18:10:33 2001