| Author | Message | ||
     David_nebenzahl Tinkerer Username: David_nebenzahl Post Number: 241 Registered: 12-2009 Rating: N/A |
It's not clear that you're doing things in the right order here, at least so far as I can tell. (Disclaimer: I'm not familiar with this camera at all.) My apologies if I'm missing something here. The usual course of focus correction for a rangefinder camera is in two steps: first the actual focus is corrected, then the rangefinder is adjusted. It sounds like you're saying that the actual focus of the lens is off, correct? In that case, the first step is to get the lens focusing correctly. This is done by adjusting the focus at infinity, and can be done with a collimator (in the form of a 2nd camera) as you described. So far, so good. Except that you shouldn't be messing with either lens element, screwing them in or out or shimming them, assuming that they were correctly placed in the shutter (of course, that's an assumption you can't always make, but it's a starting point). Both elements should be completely screwed in, with whatever original shims were there, if any. You then adjust the focus by moving the focus ring/collar/sleeve/whatever means is used to focus the lens (this is a manual focus camera, correct?) where it is secured to the focus helical. Forget about the distance scale for the moment: you just want to get the lens focused at infinity (at the film plane) when the ring/collar/whatever is rotated all the way towards infinity. After the focus is corrected, then you can adjust the rangefinder (also at infinity). So far as the scale being off, that remains to be seen until you're sure the focus is correct. At that point, the scale should be fairly accurate; the discrepancy you reported (showing 2.85m when actually focused at 3m would not be correct, unless the scale was incorrectly printed or engraved, which would be surprising.) |