"Ian McKee" <photoian@earthlink.net> wrote:
>Calumet sells a set of twelve pinholes ranging from .0059" to .032". I have
>mounted these on a 4" x 5" camera and shot the whole series at an
>arbitrarily selected bellows extension=focal length of 210 mm. With each
>pinhole I get the same image and the same degree of sharpness. The only
>variable is exposure time.As you might expect, the smaller the pinhole the
>longer the exposure to achieve equal density.
>[...]
>Try it and see for yourself!
This has been done before - with opposite results. You can find an
example of this in Eric Renner's book "Pinhole Photography -
Rediscovering a historic technique" (Second edition) on page 129.
There are 8 images of the same object taken with a Super Speed Graphic
with a focal length of 2 1/4 inches and 8 different pinholes (f/22,
f/32, f/45, f/64, f/90, f/128, f/190 and f/288). There are noticeable
differences in sharpness from one image to the next.
This is what physics is telling us and what innumerable pinhole
photographers have experienced taking their images.
Dieter
-- Dieters Lochkamera Seite: http://www.die-lochkamera.de/ drf-Süd-Homepage: http://www.drf-sued.de/Received on Wed Dec 18 08:52:31 2002
This archive was generated by hypermail 2.1.8 : Mon 13 Dec 2004 - 23:18:50 PST