----- Original Message -----
From: "John Edwards"
> > One of the central element in this project has been the decisions to
> > make on (1) focal length and (2) pinhole diameter and thus (3)
actual
> > F/stop.
>
> So.... What were (1) and (2) - and the time????? - and did you use
single
> weight paper??
> - John Edwards, Vancouver, WA
John,
I should have been more specific. I plan to write a more detailed story
in the next few days about this project and show images of the print
(currently in paper negative form but soon to be turned into a contact
printed positive).
The image is a triptyc this is 12 1/2 feet wide by 9 feet high (3 panels
of 50'' wide) from a 100 feet long roll of Ilford Mk IV single weight RC
paper (kindly supplied by Ilford Canada through their representative in
Québec). Some have suggested that this may actually turn out to be the
largest pinhole photography ever created but it certainly was not our
intention to break a record.
So, here are the details:
. Focal length was 40'' at the center but we did what is called a "back
swing" in large format photography, resulting in a focal of about 36" at
the left extremity. This was done in order to extend the angle of
vision to the right.
. The diameter of the pinhole was 1.8mm resulting in an F/stop of
F/564.
. Total exposure time was 12 hours, strating at 01:30 AM through to
13:30 in the afternoon of sunday.
. Outside weather was hazy skies during the nigh turning to overcast in
the morning with snow beginning in the afternoon when we closed the
aperture.
The image shows quite a bit of vignetting, since we extended the size of
the image past the limits of 2 1/2 - 3 1/2 times focal length , but we
will be able to handle this at the contact printing stage and by
applying reducer on the rather dense central area of the negative.
Cheers,
Guy
P.S. The project is described at
http://www.pinholevisions.org/diary/?option=story&id=212 and also at
http://www.zeroimage.com/Guy/PinholeHotel.html
Received on Fri May 3 03:50:07 2002
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