RB67 - light leak and jamming problem

[francis_bartus]

<p>I have had a RB67 for quite some time now but only recently have I started to use it frequently. Despite my successes with the camera (which was in pretty poor condition when I acquired it) it has developed a couple of finicky problems.</p>

<ol>

<li>There seems to be a light leak coming from either the film back or the rotating back adapter (?). It always shows a similar pattern of light criss-crossing from the bottom left of the frame to the top right. I had my photo professor take a look at it for me, and he pointed out that the light seals on the top and bottom of the inside of the film door on the Pro-S back had worn out significantly. So I bought a seal kit like the one seen at <a href="http://aki-asahi.com/store/html/Mamiya-RB67/Light-seal/index.php">this page</a> and I used the two long, thin strips to replace those particular seals. To be extra-careful I also put electrical tape on the outside of the film back along the lip where the film door meets the 120 insert (perhaps a bit haphazardly). I did not seal the side of the film back - just the top and bottom. <strong>Please see the attached photo for a typical example of the light leak</strong></li>

<li>The camera seems to be "jamming" on me - as in, the shutter will not fire when I try to take a photo. I noticed that this seems to happen when I have recently rotated the back (which does not lock properly, never has). After some consistent frustration I discovered that if I rotated the back from horizontal to vertical and back again it would usually un-jam. However, I missed some key shots due to this new problem.</li>

</ol>

 

<ol> </ol>

<p>Any help anyone has would be appreciated - I am happy to replace all the seals and whatnot myself if necessary, as I have the rest of the seal kit set aside. However, I would like to know if there's a problem with the revolving back adapter or if the leak is coming from a source other than the 120 back itself.</p>

<p>If there's any other information you good folks would like - photos of the camera itself, another example of the light leak - please let me know. The photo below is a rather mild example of what the light leak is doing.</p>

<p>Many thanks and happy shooting!</p>

<p>-Francis</p><div></div>

[erie_patsellis]

<p>You need to replace all the foam in the back (and might as well check any others you have) and the revolving back needs a good cleaning and lube, as well as replacing the light seals as well. Not terribly hard to do, if you pay attention to details.</p>

[paul ron]

<p>Erie is correct, replace ALL the seals. What you have to look for in your picture, imagine how the film orientation is in the back, upside down n reversed. That's where the light leak is.<br>

I'd take off the face mask of the insret and check the internal darkslide baffle. This will also allow you to make certain all the screws are properly seated on assembly, that's another source of leaks often overlooked.<br>

The rotating back has seals on the face that needs to be replaced. Generally the halves don't leak light but I split em and relube the entire thing so the interlocs work and it glides smoothly. Maybe you have a bent or hanging pin? If it's not bent, just put a tiny dab of WD40 on each it to insure it is running smooth.</p>

<p> </p>

[erie_patsellis]

<p>Why thank you Paul, any suggestions should the OP not wish to DIY? ;)</p>

<p>Francis, if you're in the US and would prefer to have it done professionally, look up Paul, his work is first rate and he's a stand up guy.</p>

[francis_bartus]

<p>Erie, Paul - thanks for your responses. Since I bought the seal kit, which conveniently comes with the necessary tools for cleaning and replacing them, I think I'll go ahead and swap them all out on the film back and the rotating adapter at least. Also, thanks for the suggestion about lubing the rotating adapter with WD40 - that's something I probably should have done from day 1 when I bought this camera.</p>

<p>Anyway, should I do all that and not have any luck, I'll be looking you up, Paul!</p>

<p>Cheers gentlemen,<br>

Francis</p>

[john_c16]

<p>Sounds like one of the interlock pins on the rotating adapter is not extending completely or bent. I had one that was both bent and the spring inside was weak causing it not to extend properly - I bought another adapter for about $25 and replaced it. Has worked perfectly ever since.</p>

[paul ron]

<p>You are welcome. Don't lube the rotating back, just the 2 pins with a dab of WD after inspecting em. Push em in n out several times to work the lube in.<br>

As I mentioned, take the plastic mask off the insret too to inspect the darkslide baffle, it may be dirty.<br>

Now lets see some pics?<br>

Errie, how are you doing these days?... making any new cameras lately? I love that RB hybrid you have.</p>

 

[francis_bartus]

<p>Paul - noted. I will post some scans when I arrive home from work. =)</p>

[erie_patsellis]

<p>not really, the only thing I've made lately is an adapter for the Dicomed scan back for the RB, not a finely machined object d' art, but it gets the job done and rids me of a Polaroid back that was too nice to throw out, but not worth replacing the rollers on when you have a pile of them.I do need to send a 250 out to you, just haven't had the time being a f/t art major and the demands of a BFA program.</p>

<p>Francis, depending on the vintage, the earlier pins have a screw that can be removed if it's really gunked up, but unless you've worked on them, I'd not touch it. Contact cleaner does a good job of removing 99% of the old crud and grease, just be sure to replace the grease with fresh grease.</p>

[paul ron]

<p>Let us kow how it turns out?<br>

Erie, you made a scan back for the RB? What did you use as a scanner?<br>

I once had the idea to hook up a computer scanner to the back of my 8x10, back in the early days of digital. I never got around to doing it and still have the scanner n camera in the closet waiting for me. What I was baffled with was do I need something to project the image on to scan or will it focus on the scanner's glass and the sensor can read the image directly?<br>

How did you work it out? I'd be interested to see your design? Maybe start another thread on it? Or on APUG? Or Nelsons DIY? I'll bet it'l get alot of hits.</p>

<p> </p>

[erie_patsellis]

<p>Actually, I cheated and bought a Dicomed FieldPro scanback (predecessor to the Betterlight 6K), too inexpensively to pass by. I created an adapter to allow the use of a 4x5 insert onto the back of the camera, just need to do a little shimming, not a big deal now as you can check focus easily enough, but eventually, I'd be easier to use in the field if I didn't have to refocus every shot.</p>

<p>Shoot me an email and I can give you more details.</p>

<p>erie</p>

[francis_bartus]

<p>Paul - Last Saturday, I took the RB down to Washington, D.C. for the Rally to Restore Sanity. The first 14 photos in this set were taken with it:<br>

<a href="http://www.flickr.com/photos/francisbartus/sets/72157625202323193/">http://www.flickr.com/photos/francisbartus/sets/72157625202323193/</a></p>

<p>Ernie - thanks for the advice.</p>

<p>I'll let everyone know how it turns out.</p>

[francis_bartus]

<p>Here's one image from the rally:</p>

<div></div>

[paul ron]

<p>Beautiful, no leaks! I guess doing all the seals was worth the trouble?</p>

[francis_bartus]

<p>Paul - I haven't done the seals yet (probably give it a shot later today or tomorrow) -- these were just the photos that were not affected by the leak. I shot 6 rolls of 120 that day and probably lost about 7 or 8 photos to the light leak...</p>

[paul ron]

<p>You only lost a few shots out of <strong><em>rolls</em></strong> of film? Maybe it's not a leak at all n just flare? Take another look n see if you notice the direction the sun light hits the lens? Anything in common?</p>