Help with odd light leak in RB67 film back

[peter_anderson8]

<p>I have an older RB67 film back that has a vertical light leak. I redid all the seals with the Asahi kit but still have the leak.<br>

<img src="/photo/17818324" alt="" /><br>

http://www.photo.net/photo/17818324<br>

The shot was a long exposure (3 - 4 minutes) with a welder's glass over the lens. The light leak is always in the same position, and shows even if I have a very quick exposure (even 1/1400). <br>

The leak is from the older film back, not in the camera body - I've checked the bellows and they are sound. When I shoot with the newer film back I do not get the light leak. <br>

A poster on another site said to put a small LED flashlight in the filmback in a dark room. Brilliant idea. I did this and saw a thin line of light in the area circled in yellow. (when the dark slide was in place there was no light visible anywhere from the film back. <br>

<img src="/photo/17818325" alt="" /><br>

http://www.photo.net/photo/17818325<br>

And opening the film back shows the area in better detail -<br>

<img src="/photo/17818326" alt="" /><br>

http://www.photo.net/photo/17818326<br>

The light shows through at the gap between the film plate and that large roller on the right. There is no foam or light dampening there - very confused as how light can leak through here. </p>

<p>Any suggestions on how to fix this?</p>

<p>Peter</p>

<p> </p>

[c_watson1]

<p>Isn't that the side nearest the outer shell hinge? If so, that's usually the seal that causes problems. You may need to redo that. Another area that might be the culprit is the surface that mates up with the RB adapter. It's held in place with 11 small screws. There's a chance it's not flat and is leaking around the film gate. How are the seals on the RB adapter--both sides(camera+film back)? This also looks like an older Pro back with possible dark slide seal issues, too.</p>

[peter_anderson8]

<p>Yes,<br>

it'a an older Pro back. I have a Pro S body and film back, this older one was picked up off ebay. <br>

It is the side near the hinge. I'll take a close look at the seal. <br>

But, when I did the internal light check, I found light leaking out from that gap between the metal plate and that roller - odd. Was wondering if an adjustment, or something, was needed. </p>

 

[thirteenthumbs]

<p>The area you have marked in yellow is the film supply side and it is normal to have a gap between the supply roller and the pressure plate.<br>

I agree with C Watson. Check the hinge carefully with the insert removed. The light leak may be due to a worn hinge pin or loose hinge mounting rivets.</p>