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Message |
    
Dannl
Tinkerer
Username: Dannl
Post Number: 3
Registered: 03-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 06, 2007 - 10:26 am: | 
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It took me a fair number of tries to get the main curtain and second curtain to sync and come across together and to pass the general Television Test. The most difficult part was getting 1000s through 20-1 and Z to all function under the same tension settings. I was curious as to what number of turns is considered average for the Leica IIIa main curtain roller and the second curtain roller?
Thank you. Dann |
John_shriver
Tinkerer
Username: John_shriver
Post Number: 8
Registered: 12-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 12, 2007 - 07:43 pm: |
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The National Camera IIIf manual says no more than 8 turns on the opening curtain, and no more than 2 turns on the closing curtain. If it takes more than that, something is wrong, probably dirt, binding, or lubrication issues. All the bearings need to be absolutely clean of gunk, and just the slightest bit of high quality light oil.
Typical is supposed to be something like 7 and 1-3/4 turns. 4:1 ratio.
Your goal with the spring tensions is to get the exposure even side to side, and not have 1/1000 cap.
The only way to "trim" the highest shutter speeds on the IIIa or earlier is by where the curtains are mounted on the drums. Just get the low speeds right and even, and the high speeds are just "what they are".
On the IIIc and later, there are adjustable cams on the closing curtain latch for 1/500 and 1/1000 -- a much better design, honestly. But I do love my IIIa for it's charming simplicity. |
Dannl
Tinkerer
Username: Dannl
Post Number: 4
Registered: 03-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 12, 2007 - 11:00 pm: |
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Thanks John, I mean really thanks. I guess I didn't do too bad then with my 7:1.5 adjustment. I had no clue where to start or end, and dismantled the poor camera 5 times to hold it in front of a television and set an adjustment. I had almost given up, and you saved the day. Thanks again. Dann |
Wenuk
Tinkerer
Username: Wenuk
Post Number: 2
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 01, 2007 - 08:00 am: |
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John
can you still buy The National Camera lllf Manual - I have been looking for one - but all I can find is a photocopy for sale on US Ebay - I am in the UK?
Cheers |
John_shriver
Tinkerer
Username: John_shriver
Post Number: 12
Registered: 12-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 01, 2007 - 05:39 pm: |
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Not from National Camera. Someone once affiliated with them is selling genuine copies on the web, but they are not of the final edition, they are an earlier edition.
The copies will do fine. |
