matthew_rusbarsky Posted January 27, 2008 Share Posted January 27, 2008 While servicing the shutter, I noticed some lens ugliness. This is an old-style Avus with an uncoated Tessar-type Skopar in a Compur shutter. There seems to be haze (or fungus?...alsmost looks like condensation) BETWEEN the first and second groups. The Avus rack-focuses so the first two groups screw out as a unit. Has anyone taken this unit apart? Once apart does the lens need to be re-collimated? Thanks in advance... Link to comment Share on other sites More sharing options...
mskovacs Posted January 27, 2008 Share Posted January 27, 2008 I fixed an Avus with the same problem. If I recall correctly (from 2 years ago), the nameplate on the lens or a retaining ring has slots to accept a spanner wrench and clean between the elements. No collimation required. Link to comment Share on other sites More sharing options...
matthew_rusbarsky Posted January 27, 2008 Author Share Posted January 27, 2008 I wish it was that easy. Possibly I have an older version? The 1st and 2nd elements are mounted in a barrel assembly as a unit. They screw out of the faceplate easily. Next comes the shutter. The 3rd and 4th elements are cemented together as the third group. This group is easily removed with a spanner wrench. I need to crack open the barrel assembly to get between the 1st and 2nd elements. Looks like a job for flexi-clamps? but Im'm not even sure if the barrel unit is threaded together. Link to comment Share on other sites More sharing options...
mskovacs Posted January 28, 2008 Share Posted January 28, 2008 No nameplate on the front cell? It may unscrew with a friction wrench if there are no spanner slots/holes. I can't see how a flexi-clamp is going to help. A picture is worth a thousand words if you can post some. Link to comment Share on other sites More sharing options...
Matthew Currie Posted January 28, 2008 Share Posted January 28, 2008 Having just a couple of days ago acquired a 9 x 12 Avus with a Skopar 13.5 lens, I opened it up, and indeed, if there's a way to get that front element apart, it's well hidden. It looks to me as if the barrel is in one piece, and the only way to get the elements out would be to remove the front ring (the one with the writing on it), which has no notches or pin holes. Even then there's no guarantee that the elements aren't glued together. Link to comment Share on other sites More sharing options...
matthew_rusbarsky Posted January 29, 2008 Author Share Posted January 29, 2008 From a later (rim-set) Avus manual: ...it may happen that also the inner surfaces of the lens may collect moisture. Then carefully unscrew the two halves of the lens fromn the shutter. On no account must any attempt be made to unscrew the seperate parts of the front and rear lens elements for it's beyond the skill of even an experienced amatuer to put them together again as to restore their original optical quality. A few (poor) photos of the front "half of the lens. It screw directly out of the shutter. Behind it are the blades and then the double third group. Front: http://i103.photobucket.com/albums/m137/Proteus617/DSC02547.jpg Rear: http://i103.photobucket.com/albums/m137/Proteus617/DSC02548.jpg The out of focus brass threads you can see in the second photo screw the unit into the shutter. The warning in the manual has made me think twice sbout trying to screw the unit apart. Link to comment Share on other sites More sharing options...
matthew_rusbarsky Posted January 29, 2008 Author Share Posted January 29, 2008 Fixed the tags: Front:http://i103.photobucket.com/albums/m137/Proteus617/DSC02547.jpg Rear:http://i103.photobucket.com/albums/m137/Proteus617/DSC02548.jpg Link to comment Share on other sites More sharing options...
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