help identifying light leaks?

[cengman]

I've attached here a couple examples of negatives from the first roll of film I tested on an AGFA PD16 folding camera. I'm not sure how the pics will show up. Haven't posted any photos here before. These are not nice scans. I just wanted to put up a couple quick examples so I taped the negs to my monitor and snapped pics with my cell phone.

In the first one there's a spot near the center of the frame that I suppose could be from a leaking shutter? In both there's a problem in the lower right corner of the frame. I checked the bellows last night and I found two teeny tiny pinholes that I patched by dabbing on some black silicone gasket sealant. It doesn't seem likely that the leak appearing in the lower right corner (upper left of the camera, correct?) is from pinholes in the bellows. I see a couple hard-edged shadow lines, and the overexposed area crosses the frame line. So maybe it's close to the film plane and maybe it's coming from behind the film? I don't know...

Has anyone seen something like this, can you recommend where I might look to make the camera more light-tight?

 

[480sparky]

I see slight fogging on the top of the images. It looks more like a problem when the film was rolled up on the take-up spool... like the paper wasn't seated properly against the spool. Does the fogging diminish the closer you get to the beginning of the roll?

 

[AgX]

A spot in the center is much more likely due to a red window in the back than due to a leaking shutter.

 

[R.Gould]

The spot in the center could well be a leaking shutter, I had an Ensign that had the same problem, not on every frame, but on some, turned out that the shutter sometimes was not closing fully, a cla sorted the problem out, with ilford/kodak/foma film, the main ones I have experiance with in folders, the red window would not cause this, it would need to be very bright indeed to fog the film though the backing paper, I have never seen it happen, and I rarely close the red window sheild on any of my extensive collection of folders when using the.red window, to check open the camera and hold it up to the light and if you can see a light from the shutter when closed after a few firings then you know what the problem is
Richard

 

[cengman]

Thanks for the ideas.

Re: the fogging in the center of the frame - the first thing that occurred to me was the counter window, but it's really not positioned anywhere near the center of the frame on this particular camera. It's much closer to the top right corner. I did a DIY CLA on this shutter after I got it. (When I first got the camera, the shutter did not work at all. It was completely seized up with old lubricant.) The shutter seems to be working smoothly. I tried firing it several times while looking at a strong light through the back of the camera. If the shutter is still sticking, it's not obvious to me. I'm concerned, though that when I reassembled the shutter, I didn't know that there might be a specific order for reassembling the shutter blades. They all looked identical and I just put them back together in a way that looked right. I think it's possible that the blades are in the wrong positions and are not lying flat allowing a little light to creep in.

Re: the fogging at the top left of the images. I think you're correct sparky that that occurred when I took the film out of the camera. It's definitely worst on the last two frames from the roll. I'm using 120 film on a 616 camera so I need to clip a little off the edge of the 120 spools so they will fit in the camera. I think it's possible that the trimmed spool is not completely covering the edge of the film. I'll have to change film in the dark and keep some foil around to wrap my exposed rolls.

Re: the fogging in the lower right corner - This is present in all but one exposure on the roll and it's doubled up on a couple of the frames. I'm starting to think I may have a leak at the film door hinge, the film is getting fogged at that spot while it's still on the spool and that spot just happens to coincide with the left edge of the film gate when I advance the film. I added some strips of felt in and around the hinge, I may cover up the hinge with a piece of tape, too before I shoot the next roll and see if that fixes it.

Thanks for all the ideas!

 

[summicron1]

i would check and make sure the film is rolled tight and only changed in dim light. Check and make sure the inside of the camera doesn't have any bright spots -- even shiny black can cause reflections -- and that all your hinges are tight.

the shutter on one of those is just a flap, not a set of blades that doesn't close quite all the way leaving a tiny hole open. I'd look elsewhere for that center spot fog -- reflection, say. Or a ghost.

the clipper is a stylish version of a Holga, with all the quirks attendant thereto. Wouldn't hurt to put some black tape over the red window between frame windings, just to be safe.

 

[cengman]

Mine is a pd16 "viking." It's not the clipper. It's a folding camera with f/6.3 leaf shutter lens with 5 blades. I think it's definitely possible that in reassembling the shutter I laid the blades together in a way that they are no lie perfectly flat. It's got a sliding cover for the counter window as well. I'll definitely be more careful about keeping the cover closed.

 

[Xmas]

I've attached here a couple examples of negatives from the first roll of film I tested on an AGFA PD16 folding camera. I'm not sure how the pics will show up. Haven't posted any photos here before. These are not nice scans. I just wanted to put up a couple quick examples so I taped the negs to my monitor and snapped pics with my cell phone.

In the first one there's a spot near the center of the frame that I suppose could be from a leaking shutter? In both there's a problem in the lower right corner of the frame. I checked the bellows last night and I found two teeny tiny pinholes that I patched by dabbing on some black silicone gasket sealant. It doesn't seem likely that the leak appearing in the lower right corner (upper left of the camera, correct?) is from pinholes in the bellows. I see a couple hard-edged shadow lines, and the overexposed area crosses the frame line. So maybe it's close to the film plane and maybe it's coming from behind the film? I don't know...

Has anyone seen something like this, can you recommend where I might look to make the camera more light-tight?

The backing paper normally protects the film from the back, those look like leaks from front.
There looks like there is edge fog in the first scan top left as well?
You would need a leak into either film chamber screw missing or may be rear door.
You might need to try another film with the rear door taped up.

 

[nosmok]

You mention cleaning the lens or shutter; I had a camera that had a center leak from around its lens-- I mounted an identically spec'ed lens to replace one that wasn't working and could not get the new lens to seat perfectly (it was same fl and speed but a touch smaller in diameter). I wrapped black yarn around the outside of the mounted lens and that has cured the problem. tl;dr: Check yr lens mount if all else fails.

I find that by taking a 6x9 folder outside and holding up tight to one eye I can see pinholes pretty well, once my eye adjusts. To check what I see, I take whatever fingers I can pry loose and put one over the bellows exterior where I see a spot. If it goes away, bingo. I use thin vinyl tape to fix, still trying to find a good brush on solution.

 

[gone]

I use the "eye inside the bellows and take it out in the sun" trick a lot w/ folders too. Works well. My guess is its a bellow light leak, probably at a crease in the fold. Leaks at the bottom are tough to discover.

 

[shutterfinger]

I think it's definitely possible that in reassembling the shutter I laid the blades together in a way that they are no lie perfectly flat.

I finally found a picture that shows the shutter blades clearly, http://www.google.com/imgres?imgurl...vGsXaoAT1jIDQCA&tbm=isch&ved=0CBQQMygMMAw4rAI ,
starting the pivot closest to the 6 o'clock position lay the 1st shutter blade in place and continue in a counterclockwise direction until all blades are in place.

If the blades lay in with the front lens mount facing down then start at the 7 o'clock position and lay the blades in a clockwise direction.