Yashica Lynx 14E rangefinder calibration

[Jonathan-Mac]

Hi everyone, I'm new here.

I've just opened up my recently-acquired Lynx 14E because the rangefinder patch only moved from infinity to around 8 feet, below that it didn't budge. I found the problem and sorted it, loosened up the RF adjustment screws (they were stuck) and have put the camera back together. Now I need to calibrate the RF again.

I've found that when I have it perfectly calibrated at infinity using the hard-stop at infinity on the focusing ring, focusing on a target at exactly 2m, the distance on the focusing ring reads very slightly over 2m. It's not much, around 2mm over the 2m mark. At the minimum focus of the lens (0.8m) I measure the film plane as 0.74m from the target.

So in order know if this is OK my questions are:

Is the hard stop at infinity really infinity or does the lens focus slightly beyond infinity?

Would I be better to calibrate the RF at shorter distances instead of at infinity?

If there is a slight difference, how noticeable will it be? How far would I likely need to stop down to hide a possible tiny focus mis-alignment at minimum focus?

Many thanks for any help

 

[mburns]

The hard stop at infinity is as accurate as the factory technician managed to do it. I have a Yashica rangefinder camera with which I used hyperfocal technique and high iso film. This turned out to be for the best, since the 20 foot mark on the lens gave sharp focus at infinity when I finally studied the issue.

The adjustments on a rangefinder are only two in number. So precise focus can only be expected at two distances. Any simple design can not do all of the trigonometric corrections. The obvious candidates for precise focus, then, are at minimum focus distance and at infinity.

 

[mburns]

The hard stop on the lens is another independent adjustment.