A little edge fog on 6x9 negatives from Horseman backgreenspun.com : LUSENET : Large format photography : One Thread
I've been using Kodak NC 160 film in a new Horseman 6x9 back on an Arca Swiss FC Metric. Lately I get the occasional frame where there is a bit of fog - a 1/2" zap of exposure is a more accurate way to describe it - in the gap between frames. It does not get on the image area as far as I can tell, but I am concerned that it might. It's pretty close to the right edge of one frame. It seems random. Some rolls don't have it at all, some have it a couple of times. Anyone else get this sort of thing? Whatsit from?
-- Sandy Sorlien (firstname.lastname@example.org), December 05, 2001
Sandy, I think it`s a ghost in the machine... On occaision I`ll get some edge fogging, but not always on the same camera or back. Pretty much at random. Often loading/unloading in more light than I`m comfortable with, is likely to contribute. Steve
-- Steve Clark (email@example.com), December 05, 2001.
I've had this intermittent problem too. I have three different roll film holders (Calumet C2, Horseman 6x7, and Wista 6x7) and the band of fogging only occurs with the Horseman and the Wista. I suspect that it has to do with film curl, and the way the pressure plate is able to hold the film flat enough to prevent light leaks coming in from the sides of the rectangular window. With the Horseman and Wista holders, the film is bent sharply against the roller and is immediately fed onto the smallish pressure plate. With the Calumet holder, the film gets pulled through a longer distance and against a wider area of the pressure plate before it gets to the exposure window. This probably allows enough slack in the film for the Calumet's pressure plate to counteract film curl, and to hold the roll firmly. Also, compared to the Calumet holder, there seems to be more space between the pressure plate and the exposure window in the Wista and Horseman, although I could be wrong on this one.
-- Rico Obusan (firstname.lastname@example.org), December 06, 2001.