Washer in lensgreenspun.com : LUSENET : Large format photography : One Thread
I disassembled the front components of my Nikkor 300mm/f9, Schneider Super Angulon 90mm/f5.6 and Rodenstock Sironar 150mm/f5.6 Apo at the same time and after cleaning the lenses I found a very thin brass washer on the table. I also found an identical one in place in the Copal # 0 shutter of the Super Angulon and there is no washer in either the shutter of Nikkor or Rodenstock. I am sure the washer that came off is not from the Nikkor which has a No. 1 shutter but I am not sure should it go to the Rodenstock so that it has one washer too, or should it go to the Super Angulon so that it has two washers. I am also wondering if I had lost one larger washer for my Nikkor. Thanks for your advice in advance.
-- Lee Chen Wah (firstname.lastname@example.org), June 23, 1999
1: Tis is not a washer 2: This is a spacer used to place the front and rear cells the proper distance from each other for proper performance. 3: Not each lens and shutter combination use a spacer 4: Some might have a spacer 5: Some may need more than one spacer 6: Spacers come in different thicknesses 7: If you have say two 90mm 4.5 Grandagons in Copal 1 shutter youmight have a spacer in one and none in the other. 8: Without the proper tools you can not determine which lens lost the spacer. This should be done by a qualified service person or the authorized service center.
WHEN TAKING THINGS APART NOTHING SHOULD BE LEFT OUT AND EVERYTHING MUST GO BACK WHERE IT WAS. IN THIS CASE YOU HAVE MATERIALLY REDUCED THE PERFORMANCE OF AT LEAST ONE LENS!
-- bob salomon (email@example.com), June 23, 1999.
Just remember the advice of Red Green, everyones favorite handyman. When you take stuff apart or put it together, save all those extra parts, they might come in handy some day.
-- Dan Smith (firstname.lastname@example.org), June 24, 1999.
After I have submitted my previous question, I found another spacer in place in the Rodenstock shutter and the spacer is darker in color. I then think the spacer that came off is from the Super Angulon just because it is identical in color (bright bronze color) to the one that is in place with the Super Angulon. It seems that in my case the spacers manufactured by Rodenstock are different in color from that of Schneider. Will anyone please confirm my assumption? Is there any way to get assistanc from Schneider or Rodenstock on this regard? Larger format lenses are made in a way that they can be easily taken apart but why they are assembled with such a weak link. I agree that the quality of the lens with a misplaced spacer will be affected but is the deterioration of quality noticeable. If it does, does it mean I can test the lens by taking slides with all possible combinations of spacers and then identify the right choice?
-- Lee Chen Wah (email@example.com), June 24, 1999.
"but is the deterioration of quality noticeable. If it does, does it mean I can test the lens by taking slides with all possible commbinations of spacers and then identify the right choice?
Don't waste your time! Just bite the bullet and sent the lens into an authorized repair shop. Or wirte SK Grimes at firstname.lastname@example.org.
-- sheldon hambrick (email@example.com), June 24, 1999.
We are the U.S. Rodenstock distributor. You can call our service center at 973 808-9626 and explain to them what the problem is. Since we are also the U.S. Linhof distributor they also service Schneider lenses.
I doubt color of the shims is an indication of manufacturer. More likely they were made at different times, or by different suppliers or are different thickness.
-- bob salomon (firstname.lastname@example.org), June 24, 1999.
Lee Chen Wah, They do this because Shimming is cheaper than Machening the dimensions necessary for each lens. These (Biotar) designs are very sensitive to element spacing. Viewing the arial image with a loop should tell you the answer. I suggest to use Ron Wisner's suggestion in Camera and Darkroom Techniqes several years back, Use a non-frosted light bulb and news paper as a cheep optical test bed.Set it up across the room (Take the back or ground glass off of the camera). Just screw the lens cell in/out for best performance... Mike Phifer
-- Mike Phifer (Phiferm@aol.com), July 19, 1999.
Lee Chen Wah, They do this because Shimming is cheaper than Machening the dimensions necessary for each lens
Who are they?
Lens manufacturers don't make shutters. They buy them from the shutter manufacturers. Copal, Prontor, Rollei, Hoseman, Sinar, etc.
Shutter manufacturers don't know what lens from which manufacturer will go into a specific shutter when the shutter is made.
Lens manufacturers each have their own formulations which require differnt spacings in the shutter.
So who would machine what? You wuld end up with shutters no one could afford as they would need to be custom manufactured for each lens from each manufacturer.
The closest shutter manufacturer/lens manufacturer relationship ended in the late 70's. That was when Carl Zeiss stopped making larger format lenses. Since Prontor Werke (Compur and Prontor shutters) is a part of Zeiss the Zeiss group was making both the lens and the shutter. When they stopped making lenses that relationship ended. And now they have raised the priceof their shutters to the lens makers to a point where the shutters are virtually non-ex
-- bob salomon (email@example.com), July 23, 1999.