Fogged Edge On 4x5

[Tony Galt]

I have a question about edge fogging. I've put an image of the particular kind o f fogging I got on line at:

http://www.uwgb.edu/galta/fog/fogged_edge.htm (underline between "fogged" and "e dge".)

The fogging shows minute striations and occurs on the end of the film which is u nder the flap. It occured with a new holder. It doesn't seem as if it is a matte r of the tape leaking light. In fact, examing the holder itself, it would seem t o me that light leakage of that kind would be difficult because of the light tra ps built into the flap itself. The holder is a Fidelity elite, used only twice b efore this sheet of film. I recall that when I used to fumble around with loadin g 120 film into reels for developing that sometimes I'd get "half-moon" marks th at fogged the film and resulted from mechanical creasing of the film. I did fumb le around a bit loading this particular set of holders (new film Ilford Delta 10 0 seemed a little thinner than the Plus-X I was used to and I had a little troub le finding the holder's grooves the first time around). Can there be mechanical sources of fogging as well as light leaks? Any guesses as the source of this kin d of fogging?

Fortunately, I work digitally after I develop the film, so I was able to clone o ver the damage on the image.

[Jeff Scott]

I had a simlar problem years ago with Toyo holders but it turned out the problem was a defective batch of film. I realized this since I was using two different kinds of film in the same holders with the same loading and unloading technique. So I would recommend processing a sheet straight from the box without loading or exposing it to see whether the film is fogged out of the box.

[Tony Galt]

Other sheets from the same box of film do not show this fogging, so I don't thin k it is a defective batch.

[Pete Andrews]

"....occurs on the end of the film which is under the flap." - The film shouldn't be under the flap of a double darkslide. The film should rest in the holder just short of where the flap folds down. If you trap the film under the flap then the holder won't shut properly, and yes, it will leak light in that condition.Make sure you push the film fully up into the holder before closing the flap.

[Tony Galt]

I don't know how you figure that. With the film slid all the way into the holder , the flap covers about 1/8 " of the film yielding the clear border at that end.

[Kevin Crisp]

Tony: I agree with the last post. On the film holders I use (which is lots of different ones) the film when fully inserted is not under the flap. You can shake them all back and forth and hear the film to check and see if they're loaded. Couldn't do that with the film stuck under the flap. The light trap built into the flap won't work if film is in that space.

[Tony Galt]

There must be two designs for holders then. On both the older Riteways I have, a nd the newer Fidelity Elite, when the film is fully inserted the notched edge is under the flap (there is clearance) and the flap closes so that it is flush wit h the rest of the holder frame and is, presumably, light tight. I still don't un derstand where my fogging came from. Maybe it was a fluke and won't occur again.