I have a Vivitar flash that is rated as having a flash duration as short as 1/30000 of a second. With color print or slide film, when the flash is used at close to minimum distance (faster quench time) the images have a decided green color cast. I don't know if this is a function of reciprocity failure or just something to do with the flash. Anyway, images made at farther distances look fine.
William in Utah. 5/24/02 4:11:53 PM, "William Robb" <[EMAIL PROTECTED]> wrote: >----- Original Message ----- >From: Peifer, William >Subject: Reciprocity failure in short-duration exposures? > > >> Hi gang, >> >> OK, so I'm really enjoying a nice leisurely read of Ansel >Adams' "The >> Negative". For those who haven't had the pleasure of reading >it yet, I'll >> mention that this is a REALLY GREAT BOOK. All that talk about >the Zone >> System being complicated? Why not at all! Adams makes it all >quite >> straightforward. > >It ain't rocket science. >Tang and WD-40 are rocket science. >> >> Now for my question.... I'm quite familiar with the concept >of >> long-duration reciprocity failure when making extremely long >exposures, and >> I understand the physics behind it as well. What I wasn't >familiar with was >> the fact -- apparently -- that when using electronic flash, >flash duration >> can be sufficiently short that one needs to worry about >short-duration >> reciprocity failure. Is this only a problem with older >emulsions with >> poorer reciprocity characteristics? (For example, Tri-X.) >Anyone have >> experiences in which they needed to make exposure corrections >when shooting >> with flash using such an emulsion? > >I have never run into a short exposure reciprocity problem. I am >pretty sure that consumer flash equipment isn't capable of >giving a short enough duration discharge. >Some of the specialized short burst studio lights probably are >able to cause reciprocity failure. > >William Robb >- >This message is from the Pentax-Discuss Mail List. To unsubscribe, >go to http://www.pdml.net and follow the directions. Don't forget to >visit the Pentax Users' Gallery at http://pug.komkon.org . - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
