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Riccardo
Tinkerer
Username: Riccardo
Post Number: 5
Registered: 12-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, September 22, 2008 - 01:32 pm: | 
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On my Leica R4, I have a strange issue: when I depress the shutter release, teh automatic diaphgram mechanism closes (seems reasonably fast) and then a delay occours. I think it has always been there, like 1/10th of a second, but suddenly it became estremely long, even a second! Then the mirror slaps up and the shutter fires.
I also notice that the reopening of the diaphgram is "slow".
I thought in a problem with the automatic diaphgram of the lens, but removed and stimualted manually it seems to react nicely, also the camera behaves the same without lens and seemingly on all shutter times.
Any hints ?
--Ricardo |
Mikel
Tinkerer
Username: Mikel
Post Number: 109
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 26, 2008 - 04:38 pm: |
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As I recall, this camera reads the TTL light meter, stores the reading, stops down the lens, and reads the light again. There is a time delay involved here in order that this sequence of events can take place.
It sounds as if your camera is having a problem with the memory time lag. It could be caused by several components.
Do you want to try to repair this yourself? |
Riccardo
Tinkerer
Username: Riccardo
Post Number: 7
Registered: 12-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, September 27, 2008 - 12:58 am: |
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Yes, if it is possible, yes.
What disturbs me is that the delay is not constant, this is why I am thinking that the culprit is the automatic diaphgram.
The delay happens also in manual mode and even without batteries using the fixed 1/100". |
Glenn
Tinkerer
Username: Glenn
Post Number: 434
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, September 27, 2008 - 07:00 pm: |
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If the problem occurs in a purely manual (battery less) mode, then you must be looking for a mechanical malfunction. Your original post also indicates that the problem is seemingly confined to the camera body, so you should start by looking at the mechanicals. |
Mikel
Tinkerer
Username: Mikel
Post Number: 110
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, September 27, 2008 - 10:21 pm: |
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There is a mechanical air cylinder at work here and if the delay is purely mechanical, that is where it most likely exists.
Looking down from the top of the camera, it is at the right of the mirror box. There is a screw at the top for adjustment but I don't think that will bring it into compliance. I think that you need to clean the cylinder and I recommend ronsonol. You need a 56 millisecond delay here. |
Riccardo
Tinkerer
Username: Riccardo
Post Number: 8
Registered: 12-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, September 29, 2008 - 04:02 am: |
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Thanks for the hint, Mikel.
yes, I confirm that the problem is mechanicla, it happens without batteries.
I also put the camera in mild sun and the heat made it operate perfectly, while just in shadow makes it operate worse. Interestingly refrigerating it to about 7 C (and in winter it gets much colder) it didn't worsen significantly.
I thought the delay cylinder was a damper for the mirror (haven't opened the camera yet), as the Rolleiflex SL66 has. Here the delay is between the diaphgram and the operation of the mirror itself.
The cylinder should dry-run or should be oiled?
Are there good instruction for opening the camera top without damaging it=? |
Mikel
Tinkerer
Username: Mikel
Post Number: 111
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 02, 2008 - 07:33 pm: |
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I am just operating from memory, Riccardo, but I am sure that it a pneumatic cylinder.
As for removing the top, it is basically a Minolta XD so if you can get a diagram for that model, it is essentially the same except for the lens mount.
Sorry that I cannot recall it from memory. It's been a few years!
The symptoms would indicate that the cylinder was lubed with a light oil at assembly.
I would clean it with Ronsonol and lube it with a very light oil such as Nyoil and give it a test. |
Unikad
Tinkerer
Username: Unikad
Post Number: 1
Registered: 06-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 12, 2009 - 01:57 pm: |
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Hello,
I´ve got a problem with my Leica R4. In all auto-modes, the time the shutter opens for, doesn´t equal the metered exposition time. For instance...in the aperture mode: I choose f/2,8, the resultant time is 1/1000, but the shutter opens for even several seconds. But in Manual mode everything works OK. Could you please help me what to do with this? |
