Re: [pinhole-discussion] pinhole light falloff vs. circle of coverage question
- Original Message - From: Uptown Gallery mur...@uptowngallery.org If one set up a 4x5 bellows camera for pinhole with an appropriate pinhole for double extension (say 300 mm), placed the bellows at 300 mm but used a 4 x 5 filmholder, would that place the worst of the edge falloff outside the 4x5 image? It seems to me that this would work, at least to reduce the effect somewhat. Although fall off, technically speaking, starts right as soon as we depart from the very center of the filmplane, it'll not be noticeable until a distance around half the diagonal of the image format. In other words, as long as your focal length is equal or greater than what it is considered the normal focal length for the format, the fall off can be disregarded. As a matter of fact, if you are enlarging a negative made with a 150mm focal length pinhole, and you use a 150mm enlarging lens to do it, the fall off in the negative will be corrected by the fall off of the enlarging lens. This is one of those cases in which 2 wrongs make a right!! Guillermo
Re: [pinhole-discussion] pinhole light falloff vs. circle of coverage question
At 300mm, fall off would be way outside a 4x5 negative. I use 125mm cameras with no noticable fall off. Pretty long focal length at 300mm though and lng exposures. Nick On Thursday, April 10, 2003, at 07:32 PM, Uptown Gallery wrote: Hello: If one set up a 4x5 bellows camera for pinhole with an appropriate pinhole for double extension (say 300 mm), placed the bellows at 300 mm but used a 4 x 5 filmholder, would that place the worst of the edge falloff outside the 4x5 image? It seems to me that this would work, at least to reduce the effect somewhat. Murray ___ Post to the list as PLAIN TEXT only - no HTML Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/ -- Nick Dvoracek dvora...@uwosh.edu Director of Media Services Voice: 920-424-7363 University of Wisconsin Oshkosh Fax: 920-424-7324 http://idea.uwosh.edu/media_services/home.html http://idea.uwosh.edu/nick/handouts.htm
[pinhole-discussion] pinhole light falloff vs. circle of coverage question
Hello: If one set up a 4x5 bellows camera for pinhole with an appropriate pinhole for double extension (say 300 mm), placed the bellows at 300 mm but used a 4 x 5 filmholder, would that place the worst of the edge falloff outside the 4x5 image? It seems to me that this would work, at least to reduce the effect somewhat. Murray
