PDA

View Full Version : Strange fogging



Matt_Bigwood
10-Jan-2009, 01:59
I used my old MPP Micropress last week (English press camera, similar to a top rangefinder Speed Graphic) and shot some pictures using the focal plane shutter and a barrel Ross Xpres 6inch f3.5 lens.

Every neg (eight of them) has this strange fogging. I've looked at the bellows in a darkroom using the technique of putting a flashlight inside, but can't see any light leaks.

The fogging always occurs on the side of the negative opposite where the film holder is inserted. I know the film holders aren't to blame as I've used them in my other MPP MicroTechnical without a problem.

I was wondering whether it was caused by the shutter curtain or the camera body itself?

Matt

Vaughn
10-Jan-2009, 03:25
It does not look like the fog is coming from the direction of the lens and looks to be coming in almost parallel to the film holder (due to the bit of the neg not fogged at the edge.) It does not appear to be a bellow leak either.

I would recheck with the flash light again -- try to use something like a small maglite that one can remove the front lens and just has a bare bulb...this will provide light radiating in all directions. Just a regular flashlight will not allow much light to shine 90 degrees from where it is pointed...which is what you need. Pay close attention to where the film holder and the film back meet, and where the film back and the back of the camera meet. Make sure you give you eyes a long time to adjust to the darkness.

How are the springs? If they are much weaker than your Micro Technical, you might be pulling the film holder slightly towards you as you pull out the darkslide...but this is a long shot.

Best of luck in your investigation!

Vaughn

PS...if the leak is always from the end that one inserts the holder, you must have had the back turned "upside down" to load the holder from the bottom in the image of the building. Since there is less light shining on the bottom of the camera than the top, it makes sense that there is a greater amount of fogging going on with the image of the girl, since that film holder was loaded from the top.

Using a darkcloth and keeping it over the camera, even when pulling and reinserting the darkslide, might give a temporary cure to the problem.

PS#2 I would hazard a guess that the leak is more likely to be where the film back and the back of the camera meet. If it was from where the holder and the film back meet, one would have a longer shadow cast (the thin strip of unfogged film at the edge would be wider).

Matt_Bigwood
10-Jan-2009, 03:31
Thanks Vaughn - that's given me something to think about. I don't think the springs are particularly weak, but I'll check that as well.

Matt

Vaughn
10-Jan-2009, 03:43
I hitch hiked for three months in New Zealand with a 4x5 camera that had a bad light leak between the back of the camera and the film back. No fun at all to come home to develop my film and find just about all my negatives (except the few I had the darkcloth over the camera) were hopelessly light struck.

Vaughn

Matt_Bigwood
10-Jan-2009, 04:04
Sorry to hear that - it must have been heartbreaking.

I've removed the back, cleaned it and I'm going to reassemble it. I'll try taping around the sides where it looks like the light leak might be and take a few test shots

Matt

Glenn Thoreson
10-Jan-2009, 11:02
Insert a film holder and, with the lensboard removed so you can look inside, go all around the outside of the rear of the camera with a strong light. If it's leaking where the holder meets the back, you should be able to spot it. Maybe a little unevenness on the camera back? It should show any leaks from where the back is attached to the body, too. Those are dificult to find on a camera with a focal plane shutter. Good luck.

Andrew O'Neill
10-Jan-2009, 11:40
Do what Glenn suggests, but do it in a darkened room with focussing cloth over your head. Wait awhile until your eyes become more sensitive to low levels of light. If there is even the slightest leak, you will see it. I doubt it's got something to do with the focal plane shutter. Sounds more like a weak spring on the back.
Have you tried taking a photo with a dark cloth over the camera right from when you remove the slide, and keeping it there until you put the slide back in?