Light leak or shutter issue?

rob_gervais · Nov 2, 2022

I've been refurbing a Kodak Panoram No. 4D and finally am taking test shots. I'm trying to get it ready for a trip in a couple weeks.

Each test shot has vertical lines at the same spacing. I don't see any light leaks and putting a test sheet in without exposure didn't have these lines. It seems related to the swing of the lens, but I haven't identified the problem; light leak or uneven lens swing? This shot was taken using fast swing. Any help identifying/troubleshooting is much appreciated.

Oh, the circle at the top is the film advance window. Forgot to cover it.

Regards
Rob G

summicron1 · Nov 2, 2022

I have one of those cameras and for the live of me I can't see how the camera could do this. You sure the film didn't get double exposed or something? You held it up in front of a picket fence?

Very odd.

reddesert · Nov 2, 2022

I don't have one of these cameras (I have used a 35mm swing lens camera), nevertheless your shot is puzzling. What kind of film are you using (roll? sheet?) and can you post a photo or scan that shows it all the way to the edges of the film, outside the image area? Some thoughts:

there are areas of uneven density at left, bottom right, and the line running diagonally across the top that suggest a double exposure or light leaks.

It looks like you posted a positive image, and the vertical lines are dark, which would be underexposure. I can imagine a swing lens camera hanging momentarily and overexposing a vertical band, but underexposure would be harder. Also, when this happens, the vertical band is more diffuse, not so sharply defined.

I don't know how this camera returns the swing lens to the original position but one has to consider the possibility of light leaks during the return.

rob_gervais · Nov 2, 2022

Thanks, both, for your inputs. Your comments gave me ideas on how to test this out. The short of it is there are light leaks. I had tried to seal it up using gaffers tape to seal obvious leaks. I missed a bunch.

I'm using x-ray film cut down to size, so I cut one sheet into three pieces. The first I processed without exposing in any way. This was to ensure the film itself hadn't been compromised. It came out clear, as shown.

I put the second sheet into the camera and brought it outside into direct sunlight. I moved the camera around quite liberally including with the lens cover down. The result shows significant light leaks.

So, to rule out anything mechanical, I loaded the third sheet and used a whole bunch of gaffers tape to seal up the edges and any other seams I thought had already been filled due to leaks. Result is a pretty good negative.

So the lines in the previous post are definitely due to light leaks, and probably some reflections inside -- need to get some flat black paint to take care of that part.

The more difficult part will be what to use to seal up the edges of the camera. It's tongue and groove all around the panels of the camera, so whatever I use must be very thin. To make it worse, I'm in a very remote area -- the only real shopping for materials are Wal-Mart and Joann Fabrics. Maybe Ace Hardware.

Thanks again.
Rob G

reddesert · Nov 3, 2022

Great. It is good to hear about one of these unusual cameras being restored to service.

Some cameras use black yarn glued into channels for light seals. Felt is also sometimes used. You can get yarn and sheets of felt at a craft store like Michael's, and probably at a Joann Fabrics. They aren't likely to have the super thin felt that is sometimes used for light sealing on 4x5 backs and so on, but get the thinnest sheet they have and be creative.

rob_gervais · Nov 3, 2022

Black yarn is a good idea. I think I'll give that a try. I also ordered some 1mm eva foam, but it won't be here for a week. Yarn first, if it works, great. If not, I'll try the foam.

Thanks!

mshchem · Nov 3, 2022

rob_gervais said:
Thanks, both, for your inputs. Your comments gave me ideas on how to test this out. The short of it is there are light leaks. I had tried to seal it up using gaffers tape to seal obvious leaks. I missed a bunch.

I'm using x-ray film cut down to size, so I cut one sheet into three pieces. The first I processed without exposing in any way. This was to ensure the film itself hadn't been compromised. It came out clear, as shown.
View attachment 320610

I put the second sheet into the camera and brought it outside into direct sunlight. I moved the camera around quite liberally including with the lens cover down. The result shows significant light leaks.

View attachment 320611

So, to rule out anything mechanical, I loaded the third sheet and used a whole bunch of gaffers tape to seal up the edges and any other seams I thought had already been filled due to leaks. Result is a pretty good negative.

View attachment 320612

So the lines in the previous post are definitely due to light leaks, and probably some reflections inside -- need to get some flat black paint to take care of that part.

The more difficult part will be what to use to seal up the edges of the camera. It's tongue and groove all around the panels of the camera, so whatever I use must be very thin. To make it worse, I'm in a very remote area -- the only real shopping for materials are Wal-Mart and Joann Fabrics. Maybe Ace Hardware.

Thanks again.
Rob G

The good negative looks great. Get it light tight and you'll be making some beautiful contact sheets!

bdial · Nov 3, 2022

Joann's may have some black velvet ribbon too, which is similar to what some old cameras had for light sealing.

Michael Mutmansky · Nov 4, 2022

I think Joanns's used to carry EVA foam in small sheets as well for crafts, so you may be able to find some of that there as well.

Light leak or shutter issue?

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