Haven't f295 forums been shut (or are at least slated to) ?
(see http://www.f295.org/main/showthread....l=1#post129979
)
Haven't f295 forums been shut (or are at least slated to) ?
(see http://www.f295.org/main/showthread....l=1#post129979
)
Sadly f295 is no longer being maintained and presumably will die away, however people are still managing to post there. It is still possible to access the site and its marvelous archive.
It is possible to see a ground-glass image using a pinhole. But you may not want to do it. With my Tachihara 8x10 camera I can see sunlit scenes at f600 by using a really light-proof focussing cloth and staying under it for upwards of a minute to let my eyes dark adapt. Holding the breath limits condensation on the ground-glass. When the sense of heat and suffocation becomes too much I have to get out and gasp for some blessed air.
Photography:first utterance. Sir John Herschel, 14 March 1839 at the Royal Society. "...Photography or the application of the Chemical rays of light to the purpose of pictorial representation,..".
Using pinholes made from aluminum soda cans and a sewing needle, I can view the image on the glass with a wide angle field of view. The narrower the view the dimmer the image. Most of my pinholes wind up being about 1/2mm, so I measure from the glass to the pinhole in mm and multiply by 2 to get an approximate f-stop for calculating exposure. So far with B&W negative film I've done pretty good.
Since much pinhole photography is done with the camera mounted on a tripod, Replacing the ideal pinhole with a larger one just for framing becomes practical with most large format cameras. The image with an oversize pinhole will be unsharp and dim, but perhaps adequate for framing. Replacing the pinhole with a suitable simple lens will provide a brighter and sharper image. Many such lenses are sold by http://www.surplusshed.com/. Unlike a pinhole, this lens will require focusing. These lenses and extra pinholes can be mounted in lens boards. For many large format cameras, lens boards can be improvised from foam core or mat board. Two screw-in filters with the glass removed can be the basis of another way of changing pinholes. One filter is mounted to a lens board, and the other used to retain a disc with the pinhole centrally mounted. Also, a slide-in pinhole holder can be mounted to a lens board.
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