help finding the light leak

redstarjedi · Jun 24, 2015

Hello APUG. I have a contax 139 with a minor light leak. I can't seem to find it. It's a a recent purchase from Ebay, and the seller has a new light seal kit on it's way to me. I only want to replace the offending seal, not all the light seals. The link below has pictures of the seals, the negative with the leak, and the scan of the negative. It's strange it was only one frame out of may frames shot in bright strong afternoon light. I would have expected to see more leaks but it's just only one.

What i want to know is where the weak light seals are in relation to the negative.

https://www.dropbox.com/sh/r4jw6mwk7p1w85j/AADSavxaI5fRtN-I-QhSg-Wwa?dl=0

Thanks in advance.

Sirius Glass · Jun 24, 2015

The leak shows at the bottom of the image, therefore that leak is from the top of the back. Put some gaffers tape or electrical black tape across the top after loading the film and shoot the roll. That should help locate the area to the top of the back. My experience is that if you replace one seal just replace all of them since other leaks will be soon to follow.

Alan Gales · Jun 24, 2015

Replace all the light seals in the back of the camera. They are well past due.

In fact replace everything. On my 139 the foam got gummy, flaked off and bits stuck to the focussing screen. What a mess!

redstarjedi · Jun 24, 2015

APUGuser19 said:
That was a dropbox file requiring membership to view it. So I didn't see it. But already read enough. You have to replace everything. They're all offenders. GL

here are the photos from my Flickr page.

https://www.flickr.com/photos/tonywankenobi/sets/72157655033106931

The seals were replaced by the bay seller, and they look good to me.

How do i read the negative to determine if the leak is at the top or bottom ?

summicron1 · Jun 24, 2015

one spot on one edge of one frame -- hmmm. And not even all the way through the frame.

has this happened before? Is it consistent? Does it only happen when the camera is facing down taking pictures of pretty girls in swimming pools?

I almost wonder if it is an artifact from processing or something. But, whatever, if the seals along the back ridges are gummy/mushy/brittle, as these certainly are after all these years, you should go ahead and replace them anyway. Be sure to thoroughly clean the residue of the old seals off -- lighter fluid on a Q-tip works pretty well.

summicron1 · Jun 24, 2015

redstarjedi said:
here are the photos from my Flickr page.

https://www.flickr.com/photos/tonywankenobi/sets/72157655033106931

The seals were replaced by the bay seller, and they look good to me.

How do i read the negative to determine if the leak is at the top or bottom ?

the frame, in the camera would be upside down because the lens inverts the image -- so this leak, if it is a leak, is at the top of the camera's film area...but it is going to be pretty small, judging by the amount of fog you have here -- so you won't be able to see it. If you were inside the camera looking for it while the camera is closed it would be the faintest of glows....

if these are new seals, then you need to ponder elsewhere -- as i said above, artifact from processing?

try another roll, shoot it in the bright sunshine and see.

redstarjedi · Jun 24, 2015

This is my first roll through the camera, and there is no other light leak, i took this photo under shade looking down at the subject. All other frames were shot in the same bright light but at a flat eye level not pointing down.

The seals were allegedly replaced by the ebay seller, and the seals on the mirror cushion, hinge seal, and latch plate look brand new. The seals for the channels aren't mushy and look new, but not well applied. What i'm trying to figure out is from the negative if the leak is the top or the bottom of the channel seals.

Ricardo Miranda · Jun 25, 2015

First, congratulations to the OP for posting an image of the negative as a negative.

What i'm trying to figure out is from the negative if the leak is the top or the bottom of the channel seals.

The poster above you already said it is on the top channel.
As you said the seller had put new seals, you can try changing just the top one.

Congratulations on the Contax.
Enjoy it and take lots of pictures!

gone · Jun 25, 2015

Never understood why a negative is important to look at. A positive scan or print is just the opposite of a negative (negative, positive), so simply reverse the image in your head or software. White would be black, black would be white, right is left and left is right. Shoot LF for a while and you'll have even more to deal with!

You should replace the seals as a kit. If you don't, you will have trouble down the road. It's easy, but a little tedious in the mirror area. Still, easy. You'll probably need to replace the body covering too. Those were worse than the seals on those cameras.

The dropbox link, you just click on the pop up registration X and it disappears.

Xmas · Jun 25, 2015

momus said:
Never understood why a negative is important to look at. A positive scan or print is just the opposite of a negative (negative, positive), so simply reverse the image in your head or software. White would be black, black would be white, right is left and left is right. Shoot LF for a while and you'll have even more to deal with!

You should replace the seals as a kit. If you don't, you will have trouble down the road. It's easy, but a little tedious in the mirror area. Still, easy. You'll probably need a body covering. Those were worse than the camera seals.

The dropbox link, you just click on the pop up registration X and it disappears.

You need to see or look at the film cause the rebates 'tells' you this leak is not flare or a shutter problem.
I always put velvet or very thin foam in bend of door grooves, up to hinge of door.
The image is upside down and reversed left to right in the camera...
If a positive scan leak is normal daylight colour the leak in on to front surface of film.
Note this surface is facing out in a reverse wind 35mm camera.

redstarjedi · Jun 25, 2015

Xmas said:
You need to see or look at the film cause the rebates 'tells' you this leak is not flare or a shutter problem.
I always put velvet or very thin foam in bend of door grooves, up to hinge of door.
The image is upside down and reversed left to right in the camera...
If a positive scan leak is normal daylight colour the leak in on to front surface of film.
Note this surface is facing out in a reverse wind 35mm camera.

this is what the scan looks like, so then the leak would be the top channel right side?

DWThomas · Jun 25, 2015

The tricky thing about light leaks is that the exposure might have happened before or after that frame was in place for the shot, striking the film either between the cassette and the film gate prior to this shot or on its way to the take-up after the shot. Light leaks, especially this small, could be dependent on the angle of the light hitting the camera. So though you were standing in shade for this shot, might you have been holding the camera in the sun before or after?

We all agree it's somewhere along the top, as the images are upside down in the camera. I'm not acquainted with the camera, but generically speaking it could be something related to seals at the hinge or opening end of the back, as opposed to the long channels.

RobC · Jun 25, 2015

leaks like that can happen if you are gripping the camera back too tightly and the seal is less than perfect. Be gentle on your camera and make sure the back isn't bent and is closing evenly.

Yes the leak would be on the top seal approx under that screw on the camera back in your dropbox photo(3 and 4), or just to the left of it.

RobC · Jun 25, 2015

APUGuser19 said:
That was a dropbox file requiring membership to view it. So I didn't see it. But already read enough. You have to replace everything. They're all offenders. GL

if you close that popup asking for login then you can view without membership (well I can)

Xmas · Jun 25, 2015

redstarjedi said:
this is what the scan looks like, so then the leak would be the top channel right side?

Confirmed
The red colour may mean it is falling on the back of the film.

help finding the light leak

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summicron1

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gone

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help finding the light leak

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