90mm len's rear cell is to long to fit shutter...what to do?

[audioexcels]

I have a Schneider 90mm F5.6 that I wanted to drop into a Copal 0 I have. The front goes just fine, but the rear needs to be recessed just a little for the shutter to be fully active. In other words, when screwed down tightly, the shutter will not engage, but when it is just slightly screwed out, it will engage just fine. Is there any cheap trick to get this to work or anyone that knows how to deal with this on the cheaper side of the stick?

Thanks everyone!!!

[Dan Fromm]

Copal #0 Press shutter, ex-Polaroid, by any chance?

[audioexcels]

Copal #0 Press shutter, ex-Polaroid, by any chance?

I tried it with a modern day shutter. What I have discovered is the Sinar mount that it came out of recessed the rear part just a tad and so I have to figure out what kind of a ring that gives some extension would be best. It is only about 2mm's of recessing..basically what they did is take the usual part of the rear or front cells and make their own for the rear part to comply to the shutter. I could have someone drill out the piece from the Sinar and use it, but I would have to have a real precise job and then hope it slots in correctly for use with my copal 0 shutter.

Would you recommend the press shutter as an alternative or was your question asking if I was trying this with the press shutter type? If it sounds like the press would work in my case, I'd definitely like to give it a shot.

Thanks for your help!

[JW Dewdney]

I forgot exactly what the deal was - but there will be EITHER an extra shim on the cells that make them fit the sinar shutter that you need to remove - OR - you need to purchase the shims for a copal 0 (which you are lacking). That's how these things work. To get a better idea - you can call sinarbron's service dept - they're very helpful - and will give you a much better idea of the scenario if you explain what you're trying to do.

[John Schneider]

I had the same experience; I also tried mounting a 90 f5.6 S-A from a DB mount into a Copal shutter. There was a clearance groove turned into the rear barrel to clear the rear thread of the DB mount, but if you screwed the rear barrel into a Copal, by the time the groove bottomed out, the end of the barrel had bottomed out on the aperture and prevented its operation. I backed the rear element out to get the same spacing as before and used Loctite, but now the angular relation of the front and rear elements was different and the lens was never sharp. I could have machined a custom shim but the angular clocking problem would still exist; I instead became annoyed with the whole mess and I put the lens and original DB mount on eBay (good riddance). Based upon this misadventure, I look VERY warily at sellers of DB-mounted lenses who claim it's a simple drop-in fit to a Copal shutter. It may be in some cases, but not mine.

[audioexcels]

I had the same experience; I also tried mounting a 90 f5.6 S-A from a DB mount into a Copal shutter. There was a clearance groove turned into the rear barrel to clear the rear thread of the DB mount, but if you screwed the rear barrel into a Copal, by the time the groove bottomed out, the end of the barrel had bottomed out on the aperture and prevented its operation. I backed the rear element out to get the same spacing as before and used Loctite, but now the angular relation of the front and rear elements was different and the lens was never sharp. I could have machined a custom shim but the angular clocking problem would still exist; I instead became annoyed with the whole mess and I put the lens and original DB mount on eBay (good riddance). Based upon this misadventure, I look VERY warily at sellers of DB-mounted lenses who claim it's a simple drop-in fit to a Copal shutter. It may be in some cases, but not mine.

Did you ever cut out the part that Sinar did for their mount or would that be basically the same deal as what you did? I'm now seeing that even with a shim that fits precisely like the Sinar one does, it still wouldn't work. Why is this as this lens is an older version that I cannot conceive of Sinar making it work only for them and not to ever be used on a standard Copal shutter. Then again, I have no idea what kind of tricks they were pulling.

[JW Dewdney]

Are you using the proper Rodenstock shim for the copal shutter? I believe each lens has to be fitted with a shim to have optimal spacing. I also believe that if you take a 90mm already on a shutter - that you will be able to freely interchange pieces.

[Dan Fromm]

I asked whether you were using an ex-Polaroid shutter because I have some lenses that go into a cock-and-shoot Copal (also Compur) 1 with no problem but whose rear elements hit the ex-Polaroid #1 Press' diaphragm before the threads have bottomed.

[audioexcels]

I asked whether you were using an ex-Polaroid shutter because I have some lenses that go into a cock-and-shoot Copal (also Compur) 1 with no problem but whose rear elements hit the ex-Polaroid #1 Press' diaphragm before the threads have bottomed.

I figured that was what you were asking. I am using a Copal shutter to try and fit the lens. I actually did not hear back from the guy that was handling the Sinar shutter so I'm praying he knows what he is doing and that he finished the job and is a typical one of those give a call, person isn't here, well, they'll have to come in and get it if they want it type of deals. I will call first thing this morning and see what's happening and pray he did the job accordingly and also that he did not trash the shim because he couldn't contact me today!

[audioexcels]

Are you using the proper Rodenstock shim for the copal shutter? I believe each lens has to be fitted with a shim to have optimal spacing. I also believe that if you take a 90mm already on a shutter - that you will be able to freely interchange pieces.

I took the automatic piece for the rear cell down to the welding shop who does a ton of machinery also...lots of differently things really. I hope I made it clear over and over what precisely I was needing (the shim only) and to have it precision done (no slop job). He said he could do it no problem. So with hope, I will swing by there today to find the shim from the Sinar that fits precisely with this lens to make it fit accordingly. I figured the DB system does not have a market, particularly the lenses, and that I may as well try and get the original out of the auto-shutter then search (waste too much time) trying to find something or someone to make one for me. I can always just sell or give the rest of the parts to someone that may need them if nothing comes of it all and then just sell the lens cells themselves as I do not feel there is enough difference in value between one sitting in the shutter and one not sitting in the shutter other than to a person that uses the system and wanted it for their system.

Will update and let everyone know what comes of this adventure. I will say one thing, and I'm sure it has been said before...unless one is absolutely certain about the value of the DB to modern shutter route or they just so happen to have tons of shutters, I would not advise going this route as the difference in price is not worthy of buying the cheap DB mount cells only to have to pay the money for the shutter. I.E. I saw a Copal 3 that had the timing off a little...that was a 300mm Siranon/Sinaron (cannot recall the designation) that would have been perfect for my DB 240 cells at only $240 I think it went for due to barrel bending on both sides...I tried to get that one but my bid failed..frankly, I actually wanted to use the 300mm lens, though I knew I had the option of unscrewing the shutter for a day with the 240mm lens if I wished...or to even find a way to protect cells while in the field and swap shutters/cells while out in the field since my loss is 1/4th the price of the equivalent used 300mm APO type...