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Jackson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, November 09, 2004 - 10:56 am: | 
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I recently replaced the beamsplitter in a Lynx 5000. When the work was done, I adjusted the rangefinder so images converge at infinity when the lens is racked against the infinity stop.
Much of the work I plan to do with this camera will be closeup at fully open apertures, so today I decided to also verify focus and rangefinder adjustment at approximately one meter. After placing a ground glass over the film rails, I discovered that the rangefinder and lens focus were not in agreement. I adjusted the rangefinder for exact convergence with sharp focus, but now it won't quite converge all the way at infinity.
The lens is focussing correctly at infinity, so the problem appears to lie in the rangefinder itself. Is there an adjustment for this in the 5000? |
Jackson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, November 10, 2004 - 06:30 pm: |
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Well I figured it out, so thought I'd post it for others to see. The Lynx 5000 positions the yellow rangefinder image horizontally by moving the small lens located near the beamsplitter. This lens is linked to the rear of the lens body through a pivot rod. The effective length of the rod can be varied with an eccentric screw on the top side of the rangefinder. The length of the rod determines how far the small lens moves for a given front-rear focus movement of the lens body.
In the picture below, the adjustment is dentified with an arrow. The moving lens is just below it:
Linearity adjustment
I suspect this adjustment must be reset whenever the beamsplitter is replaced. Any deviation whatsoever of the beamsplitter from the original angle (~45 degree) will require adjusting this screw. Note that this adjustment affects both infinity and close focus. Therefore, it is necessary to alternate between the linearity screw and main horizontal adjustment screw until the rangefinder and lens are in agreement at both infinity and minimum focus. A photo of the main adjustment can be found here:
Main horizontal RF adjustment (courtesy Dan Mitchell)
Hope this helps someone else to restore one of these classics! |
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