With new spring greenery popping up here, I find myself tempted to wrestle with infrared film in a 4x5 pinhole camera. I've used Maco's 820c film in 35mm for lens image making and had limited success playing with it in my pinHolga. However, I've been unable to find much, if anything, as far as data on reciprocity corrections for the length of exposure I anticipate with the 4x5. Depending on the filter used, I expect my uncorrected exposure times to run from about 1.5 minutes to 4 minutes in bright sunlight.
>>From my experiences with this film in lens images, I found a good exposure time to be about double that arrived at by application of "sunny 16" and metered readings. These exposures were relatively short, though, on the order of seconds rather than minutes. I know I'll need to bracket given the nature of IR film and will need to do some testing as well before trying to make a "real" image. I would be most grateful for any shared information that might shorten the testing phase, especially at two bucks a sheet. John Bolgiano -- http://www.dgbn.com/photo/
