Focusing with an uncalibrated camera

[Akaky]

<p> Since I own more than one camera, I am now the official family go to guy on this sort of thing, even if I don't want to be, so please bear with me here. My cousin recently bought a Bessa R3M and its rangefinder has become slightly uncalibrated at infinity. She is also reading the photography how to books and she wants to know the following: can she use zone focusing with an uncalibrated rangefinder until she gets the thing fixed and still get a good photo? I am an SLR guy so I had to say I didn't know, but I would try and find out for her, which is why I am here. It seems to me that it should be possible; all she would have to do is cover the rangefinder window with something and know her distances, but I don't want to tell her something that isn't so. So, anyone, is what she is asking me possible or not? TIA</p>

[SCL]

<p>If the distance markings on the lens are accurate (ie calibrated to actual focus at the film plane), she is relatively good at estimating distances, and she doesn't shoot with wide open aperture, it shouldn't be a major issue. Lots of cameras in the 1940s-50s didn't even have a rangefinder...one needed to either use an accessory one, or estimate distances. Of course, if she can adjust the rangefinder herself, all the better. I go thru this exercise once a year with my rangefinder bodies, the adjustment process is pretty easy, at least with mine - only 2 screws to remove to access the horizontal and vertical adjustment screws.</p>

[SolaresLarrave]

If the camera focuses well at all distances except for infinity, it can be used, probably with the exception of infinity. I have a Leica M4-P with that problem; I checked it with all the lenses I have (I was assuming that the lens had a collimation problem) and saw that the rangefinder (the patch in the center of the viewfinder) just won't align well and correctly at infinity. There's always a hairline difference.

 

It´s just OK. Just tell her that if she wants to use it at infinity, say, in a landscape, focus at something closer rather than farther, and close down the lens. I have been using my Leica that way, and all my photos are in focus. Later, she can send it for adjustment, but then... tell her to be prepared as Bessas have a tendency to get the rangefinders out of alignment with a malevolent ease...

[winfried_buechsenschuetz1]

<p>Usually it is just the rangefinder which goes out of calibration. The lens mount usually stays in place, and the distance between lens and film plane (which matters for focussing) will always be correct. So you will be fine with zone focussing, With lenses up to 50mm and aperture settings of f/5.6 and higher values, the depth of field will be sufficient to cover estimating errors. </p>

[craig_shearman1]

<p>Why doesnt she simply get it fixed?</p>

[ray .]

You can zone focus with any camera that has a lens with depth of field markings on the barrel. For

whatever f/stop the lens is set at it will be in focus within a range of distance. The f/stop marks are shown

on both sides of the barrel. Whatever marked distances fall between those marks the aperture is set at will be practically

speaking- in focus.

[JDMvW]

<p>Ditto.<br>

So long as the marked distances on the lens are accurate, and so long as you can estimate distances reasonably well, no problem.<br>

My little, beloved, Rollei 35 had no rangefinder at all, and some of my best shots were taken with it.<br>

With ISOs being what they are these days, both on film and digitally, there's normally a fair cushion in the DoF.</p>

[Akaky]

<p>Thanks for the advice, everyone, Katy appreciates it. And she is getting the camera fixed.</p>