Film fogging

I know this question has been addressed in numerous forms before but

I searched the archives and didn't exactly find what I was looking

for. Recently I have had a slight fogging problem with my last 5-6

rolls of film. The very top edge of the roll has random fogging

above the sproket holes. Also, there is fogging in between

individual frames. The frame fogging occurs where a high density

part of the image seems to carry over outside the frame whereas the

thinner areas of the negative don't fog. The pattern is rather

exact. For example, a white house that is dark and dense on the

negative seems to cast a shadow outside the frame. I've read the

posts about agitation technique causing fogging, but I don't know if

that applies here. The film is factory loaded, not bulk and my

agitation technique has been to invert for 5 sec. every 30 sec. The

problem has occured on different brands of film as well. Could this

be a light leak or is it something I am doing wrong. Thanks for any

help. If I missed something in the archives and am being redundant I

apologize.

If it is a Leica M camera, I would look at a new light shield in front of the shutter. I replaced the factory ones in two of my early M6`s, a common problem, and one M3, not a common problem.

You're looking at a number of possible causes here.

 

First, areas of dense highlights that extend beyond the frame into the clear margins between frames or in sprocket hole area is almost certainly due to halation. Another possibility is flare, tho' the only time I've observed this on my negatives it was definitely halation.

 

Fogging along the sprocket hole margins, especially the side that is uppermost when the film is loaded in the camera, is almost certainly due to bad light seals or a film door that won't close properly. Streaks running perpendicular to the sprocket hole margins, no matter where in the frame or margin between frames, is almost certain due to a problem with the light seal at the film door hinge.

 

Sometimes this is due to a problem with the door latch. I've also seen instances when a film cassette rotated just enough after loading film and before the film door was closed to cause the film door to bulge slightly. In some cases this can bend the door enough that it will need to be adjusted carefully to remove the bulge. This is almost never a problem with "plastic" doors, which tend to regain their shape once the pressure is alleviated, but can be with some of the more lightly constructed metal doors.

 

If you see fogging mostly along only one sprocket hole margin it's usually the edge that was uppermost when loaded in the camera. That's because this edge is facing toward the sky or other light sources. While the bottom edge is just as vulnerable, it tends to produce less fogging because there's less light reflected from the ground, the bottom edge is shaded by our clothing or we're using the bottom half of a "neverready" camera case.

 

I see this occasionally in film shot with my OM-1, which has needed resealing for years. Being lazy, and because the problem doesn't occur very often, I've "solved" the problem by keeping the camera body in the lower half of the neverready case. The original OM-1 neverready case is actually pretty conveniently designed so that this is practical. It's fastened via a pair of simple leather loops around the strap lugs and camera strap. The loops snap into buttons on the front of the case. No tripod screw fastener, etc. It's quick and easy to remove and replace for film reloads. So I just haven't bothered replacing the light seals. I should, tho', because if the light seals on an OM-1 are gummy it means the mirror rebound foam is shot and, worse, the unnecessary foam padding between the prism mirror and prism housing are disintegrating and potentially damaging the mirrors. Maybe after my neice is done with the camera for this high school semester I'll send it in for a CLA.

Thanks guys. The camera in question is an Elan 7NE which doesn't really have foam seals on the door. The plastic door just intermeshes with the body and doesn't appear warped or bent. The fogging on the top part of the film only happened a couple of times but the last two roles were OK so I'm not sure what to think. The "blurring" of dense highlights into the clear margins still occurs however. If this is halation as you say Lex, is there any way to prevent this or am I going to have to live with it? On the other hand if it is flare, is this something that needs to be fixed with the camera. The only other thing I can think of is that roughly the same time I started having this problem is around the time I started experimenting with long presoak times to try and remove the purple cast on some films. Sometimes I would let the film soak for around 20 minutes. I know Ilford recommends against a presoak of any kind and since some of the roles in question where HP5, could this be the problem. I don't know Kodak's philosophy on this, but I've had the same problems with Tri-X as well. My OM-1 is away for a CLA or else I would shoot a role in both cameras to prove or disprove any light leak theory. I will try soaking and not soaking my next 2 roles but just wanted to get any advice before I do so. Thanks again.

I agree that it is probably halation, I frequently see spotlights "leak" outside of the frame when I'm shooting gigs. Modern film comes with an antihalation layer, but it's (obviously) not perfect. I just live with it, and I shoot enough frames anyway that when it leaks into an adjacent frame it isn't such a big deal.

I just wanted to post a follow-up. Yesterday I developed two roles of Pan-F with no pre-soak whatsoever and there was no halation to be seen in between frames. Could it be possible that a long presoak removes the anti-halation layer prematurely and actually encourages halation somehow during development. Or, is it just a random thing that occurs during exposure and is independent of the development process? I'm no film tech expert by any means so I'm just taking a stab.

Halation cannot happen during development. It's caused when light scatters along the length of the film during exposure. The light itself will be totally blown, it will have a sort of glow around it that will obsure details close to the light.

 

Some people actually like this; if you want a real 30s feel to your shot, try a film like Efke KB50 which has no antihalation layer and little sensitivity to red light. Also use a DC-Nikkor lens to get some uncorrect aspheric aberration. For the sort of photography I experience halation in, starkly-lit gigs in dark clubs, it's just mildly annoying.

Thanks for the info Guy.I thought I might be off in my theory but figured I would aske anyway. You are right about the EFKE film. I just decided to give them a try recently and the 3 roles of KB 25 I shot all displayed some halation on the edge of the frames but didn't otherwise affect the actual image. Nice film though.

Other issues aside, I can't think of any advantage to presoaking for 20 minutes. Ilford recommends no presoak at all because their films include a wetting agent to facilitate rapid and even absorption of developer. Presoaking defeats this purpose. If you feel that presoaking offers any advantage limit it to no more than a minute.

 

There are exceptions. Efke and Agfa APX films use dyes that are almost instantly released in water. I do presoak these films but for no more than a minute. The main reason is because I reuse some developers and don't want them to turn a lovely shade of aquamarine or green.