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John Tomaszewski
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 11, 2004 - 11:30 am: | 
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Hi all,
I just received a used Spotmatic that is generally in good shape but is very inconsistant on the mirror return. At shuter speeds of 1, 2, 4, and 8 it almost never returns down, and above that it's about 75% successful. The foam is OK and the mirror doesn't stick to it.
I'm new to camera repair but I've read through books by Romney and Tomosy to see if it's something I can tackle myself. From those books, the stuff I've read here, and what I see when I take off the bottom plate is seems like it might be that the tension on the second curtain is too weak and it's not tripping the mirror release (I can send pictures if anyone cares to help diagnose). I tried tightening the screw though (turned it clockwise 3-5 times,) and didn't see much of a change. How many turns is reasonable? How will I know when I'm pushing it too far? I think Romney said try 3 turns so I was afraid to try much more. Thanks in advance for any input.
Thanks in advance, John T.
(I posted this as an add-on to another related Spotmatic topic but thought that maybe I should have started a new conversation in the first place. Sorry for the double osting) |
rick oleson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 11, 2004 - 12:12 pm: |
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The linkage is probably sticky... increasing the curtain velocity may let the shutter overcome it, but it's probably just masking the original problem .... and you'd also need to boost the opening curtain to match or else your shutter will fade.
 = |
Ed
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 11, 2004 - 12:41 pm: |
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The second curtain should close with authority- but not strong tension, when tripped, if you pull it back it should return, not sluggish and as Rick says, the 1st curtain should match. You can get a rough idea (not having a tester) by observing the shutter trip thru the back looking at a flourescent light--at top shutter speed--it should be even. Under these conditions, the mirror should return--if not, the problem is elsewhere. If it is a Spotmatic, it could be problem with the meter switch release mechanism. |
John Tomaszewski
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 12, 2004 - 07:48 am: |
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Thanks Rick and Ed for the replies. I was hoping the 2nd curtain teinsion might be the likely fix as that seemed to be the easiest and only required taking off the bottom cover. I can observe the gear with the little pin on it that trips the mirror release but sometimes it just doesn't seem to push it far enough. From the bottom I don't see any obvious places to oil or remove old lube. If it's a lubrication issue is it most likely to be up in the mirror box itself?
By the way, I did check the slow shutter speeds with my camcorder (by counting the number of frames elapsed during shutter release) and they seem fine up to 1/30. For the faster shutter speeds though I couldn't quite figure out how to interpret the patterns of light, gray, and dark. I'll try the Flourescent light method and see if it's more obvious and/or the opening is even for the full trip.
Most of my testing has been with the meter left off so I'll have to try a series with it turned on as well to see if it has any affect.
Again, thanks for your time and input. |
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