| Author | Message | ||
     Richard Creviston Rating: N/A |
I have received several Emails regarding this subject so will post answers pertinant to it. Apologies for long but necessary message. This problem can be detected by removing the lens and with the back of the camera open and shutter speed set at highest speed, point the camera toward a diffused light source. Fire the shutter while observing the shutter opening from the rear of camera. You should see a complete frame of light if the shutter is not capping. Anything less than a complete frame indicates a problem. Practice this a few times and you will see what I mean. If the observed frame is dark on the left side it would indicate a too slow condition of the first curtain. (Or too fast second curtain which is not likely) This problem occurs due to the 2nd shutter curtain overtaking the 1st curtain before the 1st has completed it's travel. It usually is an indication of the need to lubricate the curtain shafts which turn in a brass bushing. If there is a squeaking sound it would suggest the need for lubrication which requires major disassembly. However in my case (No Squeaking) I corrected the problem as follows. Remove the bottom plate. Note the two small gears on the rewind side which are secured by two pawls. The front gear (Nearest to lens) controls the second shutter curtain. Rear gear controls the first curtain. The pawls which lock the small gears is secured by a Left Hand Screw. This screw is usually cemented which will require you to use a small brush and acetone to dissolve the cement. Do not rush this this cement removal and use the acetone sparingly until all traces of cement are removed. The screw, being a left hand screw, will now be removed by turning it Clockwise to remove it. This screw is very fragile and will snap easily if all cement has not been removed. Disengage the pawls from the gear teeth. Don't be concerned about the gears turning when you release the pawls as they will remain in position. In order to adjust the gears I modified a small common screw driver by cutting a square notch in the blade to fit over the gear so as to turn it. Turn the Rear gear Counter Clockwise to increase tension. (Gears are easier to access if you cock the shutter first.) Start with about 1/2 turn and check for capping. Repeat as necessary until capping disappears. Don't be dismayed if you snap the tiny screw which secures the pawls as this happened to me the first time I tried this. There is no tendency for the adjusted gears to move without the pawls in place. However I used a tiny drop of clear fingernail polish to secure the gears in case there may be a tendency for them to move from their newly adjusted position. Of course this procedure is a quick fix and may not work if the curtain shafts are badly in need of lubricating. And of course the shutter speed may be slightly altered. I have used this method on two Canons with successful results. Hope this helps you. Please advise if you have further questions about this procedure. Let me know how it turns out. Sincerely, Richard Creviston. [email protected] |