Voigtlander 25mm on a Canon 7s

[brianentz]

So I have a new Canon 7S and a new Voigtlander 25 mm lens ( new, of course, to me) I also have the 25mm viewfinder to go with. I am unable to focus through the rangefinder. For his lens, I think zone focusing will be fine, but I didn’t realize that I’m not able to focus using the patch with this lens. I am new to rangefinders and wondered if anyone had any input for me?

 

[Coldkennels]

So I have a new Canon 7S and a new Voigtlander 25 mm lens ( new, of course, to me) I also have the 25mm viewfinder to go with. I am unable to focus through the rangefinder. For his lens, I think zone focusing will be fine, but I didn’t realize that I’m not able to focus using the patch with this lens. I am new to rangefinders and wondered if anyone had any input for me?

The LTM 25mm Snapshot Skopar was uncoupled. It's got a few click stops in its focusing range, which are pre-set positions for zone focusing. What that means is you don't use the rangefinder at all, regardless of what camera it's on - you can't! I think it was intended to be used with the Voigtlander Bessa L, which came out at the same time and had no rangefinder. It's also really good on a Leica Standard, Ic, or If for the same reason.

On a related note, I always thought it was a bit weird that the 25mm in that range was uncoupled, but the 21mm (with its obviously larger depth of field) was. Seemed like the wrong way round to me. Another bit of weirdness is that the exact same lens in Nikon mount is rangefinder coupled.

Anyway, it's a great lens. Just get used to eyeballing 1m, 1.5m, and 3m distances!

 

[brianentz]

Thanks so much for your answer. Now I know what is meant by coupled and uncoupled. Zone focusing shouldn’t be an issue, I think, for this lens. Unfortunately it shows only meters and not feet on the lens and I tend to think in feet so there’s an additional mental step. Yes, I’ve read this is an excellent lens and I do occasionally like that wide take.

 

[Coldkennels]

One option for training yourself to recognise distances in meters quickly would be to pick up a cheap accessory rangefinder with a meter scale. You can carry it in your pocket and use it to check your guesstimate, even when you're not actively taking photos.

I used to do this with a Soviet BLIK when I first started playing with scale focus cameras back in 2009 or 2010 - when waiting for a bus, in line at the post office, sitting around the house killing time, and so on. You get pretty good at it surprisingly quickly!

 

[brianentz]

I’m really just getting into rangefinder Photography. I’ve been doing large medium and 35 mm. View cameras, TLR‘s, SLR’s, etc.. but I’m still figuring out rangefinders. One Canon rangefinder I was interested in was the VIL. It has frame lines for the 35 and 50 only. How would a camera like that work with 100 and 135 mm lenses? Would it require a viewfinder mounted on?

 

[Coldkennels]

One Canon rangefinder I was interested in was the VIL. It has frame lines for the 35 and 50 only. How would a camera like that work with 100 and 135 mm lenses? Would it require a viewfinder mounted on?

Yep, that's precisely how this works - a rangefinder will only have a viewfinder or framelines for certain focal lengths, and you use accessory viewfinders for anything else.

The VI-L actually only has framelines for the 50mm and 100mm lenses. The 35mm is a traditional "peephole" finder, where everything you see is what's (theoretically) included in the frame. No framelines, no "seeing outside the frame".

Another consideration is rangefinder accuracy - there are mechanical limitations to what a specific rangefinder can accurately focus. First consideration is the rangefinder baselength, or the gap between the two windows at the front of the camera. The further apart they are, the more accurate the rangefinder will be. The second one is the rangefinder magnification, which will determine how easily you can see when the images align. The two combined will give you the effective baselength, or EBL.

This is why most Canon rangefinders had a multi-magnification viewfinder; using a combined viewfinder and rangefinder setup meant they needed a comparatively low magnification (0.6x or so on the VI-L for the 35mm field of view), and as they were built in the Leica/Barnack style, they also had a comparatively small baselength. If you want to use a fast or long lens on a Canon rangefinder - especially the really early ones with a particularly short baselength - you'd be better off setting the viewfinder to the 1.5x magnification and using an external viewfinder, even for focal lengths which are technically supported in-camera (like the 50mm or 100mm). This is how I usually use the Canon IIIa, for instance.

Someone put together and maintains a chart showing the functional limits of each rangefinder body here:

It doesn't have all the Canons, but it does give you some idea of the limits of the 7/7s, the P, and the VI series.