| Author |
Message |
    
Photo_joe
Tinkerer
Username: Photo_joe
Post Number: 1
Registered: 10-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 09, 2006 - 02:44 am: | 
|
Hello,
I've searched extensively on the internet and this forum but nothing similar has been found. I'll try here and see if anyone could help diagnose my problem.
I have a Nikon FM3a that mis fires only when using a certain lens. While winding the camera with said lens the camera will release the shutter maybe 5 or 6 times on a 36-exposure roll. The misfiring happens as the film advance lever reaches it's endpoint in the winding arc. Anyone ever seen this? How to fix other than obviously not using the lens in question? The lens is a Sigma 105mm Macro lens that works fine other than this problem. The frames that the misfire occurred on appear with horizontal dark stripes once developed.
It seems odd that a lens could cause this, but then again I've no working knowledge of the guts of the winding/firing/mechanism. Could the lens cause this type of problem?
thanks in advance |
Glenn
Tinkerer
Username: Glenn
Post Number: 68
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 09, 2006 - 05:33 am: |
|
Have no experience of your particular camera, however have had this occur on certain T90/lens combinations. In these cases the faults were due to binding/bent internal actuating levers/linkages on the lenses.
The extreme case will be that both camera and lens are at fault; a combination of adjustments at the extremes of the specification ranges. The likelihood of this happening is very small, I would suspect the lens is the problem.
The fact that it does not occur all the time indicates that perhaps helical extension plays some part in this .Unless you are using the lens on manual, the aperture is difficult to assess. I do not suppose you know the actual lens settings when the 'misfires' occurred? (Some people do note such details.)
If it were me, I would try the lens on another FM3a body to see if the fault is repeatable. If this is not possible, I would at least try and ascertain the lens settings at which the fault occurred. A narrow range of values would indicate that the lens mechanism is binding/stiff at that point. Random values will not be helpful in pinpointing the fault, I would get the lens serviced.
Perhaps one of the Nikon experts out there has first hand knowledge of this fault and will be able to help you properly. |
Photo_joe
Tinkerer
Username: Photo_joe
Post Number: 2
Registered: 10-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 09, 2006 - 12:27 pm: |
|
Thanks for your reply!
I'm not sure the settings (F stop) used when the problem occurs, although it is always on manual focus and manual aperture due to the FM3a being fullyl manual. It is interesting to note that the same lens used on an automatic body has never suffered the same problem, on the automatic body the lens is always stopped down to f22 so that the electronics can take over on aperture settings, eveen though it is used manually in this setting as well.
I've no knowledge of how this type of this works but based on your message it seems that a binding or bent internal actuating lever/linkage could cause the shutter to misfire? I don't have a 2nd body to try the lens on and the've been discontinued and go for premium money these days, unfortunately.
Thanks for your help, and I'll see if others may offer some advice as well. |
|
