They're a lovely camera, one of the best lens shutter SLRs for the 35mm format I think. This is because they are beautifully made, the lenses are good and they are actually so usable. They feel like a camera decades newer, only the lack of an instant return mirror really dates them compared to 1960s or even 1970s designs. I like them a lot. But they're quite old and use a Synchro Compur shutter. Old SC shutters are likely to need some maintenance and the Bessamatic is not an easy installation to get to. So you should be prepared to get one serviced, or to learn to do this yourself, because, unless you pay top dollar for one that has already been attended to it's likely you'll need to get most examples you find sorted.
There are as I recall four types, the original, the Deluxe, the M and the CS. The CS has TTL metering but the original and Deluxe have selenium meters that are very accurate if in working order. Voigtlander seemed to have used some of the best quality selenium cells available at the time because, whilst there is obviously not a 100% survival rate it is actually still possible to find examples with good working meters even today. When I left my usual Minolta incident meter home one day some years back I had to rely on the built in meter of my original Bessamatic to expose some shots on Kodachrome 64 correctly and the exposures couldn't have been better. I was impressed with that. It's the waterfall image in this set
, and was made with the 135mm Super Dynarex on a tripod.
The Deluxe added an additional angled prism to reflect the lens opening on the ring around the bayonet mount into the viewfinder (pre-dating similar systems from other makers by some years) as well as a small rotating knob for setting the film frame counter on the top cover. The original required the spindle to be manually rotated the the correct number before re-loading. Hence the top cover of the Deluxe is not interchangeable with the other first model or other models.
I have never handled an M but it was the povvo pack version with no built in meter and no aperture setting wheel. It's quite collectable as it was the rarest version and is a clean, crisply styled SLR that's never really appealed to me because the original was so good. One interesting point is that I believe the focus screen was a plain ground glass without fresnel (I may stand corrected on that). This might be interesting because like the Contaflexes and some other leaf shutter SLRs the fresnel of the other models brightens the view considerably but at the expense of ease of focusing. Only the central microprism and split are easily focused with, the rest of the screen looks fairly sharp across a broad focusing range. The plain glass of the M would permit one to focus across the whole screen, potentially useful for some purposes and I'd be willing to try an M screen in an early model for this reason if the items presented themselves.
The Bessamatic CS has the same basic mechanism of the older model but has a different top cover and altogether different metering system, using a battery powered CdS cell for TTL measurement. In some ways it's probably the ultimate Bessamatic, I have one with a stuffed pentaprism that one day perhaps I'll get back together (I seem to recall reading that prisms from certain 70's Minolta models are a drop in fit, possibly).
There could be a few different problems a Bessamatic might have. The cocking rack beneath the lower cover can jam up occasionally, although it is one of the few repair items easy to reach. The pentaprism on some models (at least the early ones) was simply wedged under the top cover with some open cell foam. Which was quite OK for many years but the foam will almost certainly have crumbled to dust by now and need replacing. It will often be evident through the viewfinder. Taking the top cover off is not actually all that hard in itself although you have to be careful to note the gear timing from the aperture knob to the shutter rings, and also not to damage the actuating arm and peg for the meter tell tale circle, which travels in an arc around a slot inside the aperture adjusting knob, and can be bent or damaged if the knob is removed carelessly. There's a clock type spring which powers the wind lever return, best not to disturb this, as the inexperienced might have hours of fun persuading it to coil correctly around the appropriate shaft if it unwinds. Ie...SPROING! Yes, been there, done that, took me half an hour to sort the cover out and get it replaced with the spring correctly set.
The rear capping plates are sometimes not seating correctly. Whereas most other leaf shutter makers used simple spring pressure to keep the plates against their seat, Voigtlander, being Voigtlander, used an extension of the leaf shutter cocking shaft to rotate a small latch to lock the plate closed when the lens shutter is cocked. Probably unnecessary complexity, but you have to love their approach to making their best cameras. They really made an effort. It's odd, then, that when you examine the back of one they may not close all the way and latch up correctly. Why is this? I can't think of any other good reason, other than careless or stupid owners sticking their fingers into them and deforming the actuating lever inside the mirror box. It's something to watch out for.
This can be a difficult fault to fix as, at best, the top cover and focus screen would need to come off and even then the mirror will still be in the way. It retracts above the capping plate when its up and when lowered is still in the way through the lens mount. You need to reach the inside.
There is a short cut, a sneaky one but it can work. My first one arrived basically working but with a capping plate that didn't seat properly. Didn't notice it until the film came back with strange fogging patterns (I'd not long started repairing cameras, and didn't really know what I was doing yet). Anyway: with the shutter on Bulb, a locking release to keep it open and no lens on the body, you can (just) reach into the mirror box through the lens mount, gently tease the capping plate down, and carefully bend the actuating arm back into the correct profile. A small dab of grease on the end that contacts the plate and it may then work again. It did in my case.
A far as assessing the camera goes, I recommend opening the rear and looking through the back at a light source as the shutter is fired off at various speeds with a lens fitted. Unlike say, a Contaflex, the body has no aperture system. It's contained within the discrete lenses made for the Bessamatic. But they do have to be driven correctly by the actuating rings around the inside of the lens mount. Hence, keep a lens on the camera for once, when doing your preliminary shutter tests because if a particular one really is good, it will not only be able to correctly close, open and close (think about it) the shutter when you hit the release, but will also have the aperture of any lens in good order fully stopped to f/22 or whatever, *before* the shutter blades even open for the exposure. f/22 has to be f/22 for the entire exposure, you see. At 1/500 to 1/60 or 1/30 you are unlikely to be able to see any change in iris size if the stop down is not running as rapidly as it ought to. But at slower speeds the shutter will open long enough to observe carefully the size of the lens opening.
Hence, set the lens aperture as small as it goes, set 1/500 and observe through the rear of the camera. If all is well only the smallest pentagon of light should be faintly visible through the camera/lens. Repeat the test at one second, and watch, carefully, to see if any change in the iris size is visible as the shutter opens for the exposure. It should be completely stopped before the shutter blades even part for the exposure to start.
There is a school of thought that says never to use the self timers of old leaf shutters as they can make the shutter jam. Actually I disagree with that. For the most part anyway, and certainly with a Synchro Compur. Yes they can stick, and yes, the shutter won't fire off, but I've always managed to persuade one to run off fully by vibrating the housing, jiggling the arming lever, wiggling the speed ring, etc. And a working timer on a Bessamatic is a very useful feature indeed. They have a super smooth leaf shutter. Perhaps the best of all the SLR ones I've tried, even the Contaflexes that use basically the same shutters (well some models did anyway). But that total lack of vibration cannot be exploited for tripod use, because the mirror and capping plate mechanisms must first retract, and there is no pre-release fitted to the Bessamatics (or almost any other 35mm leaf shutter SLR for that matter, unlike, Eg a Hasselblad). There is only one way to pre-release the mirror/capping plate and take full advantage of that incredibly smooth shutter, and that is to fire the camera via its self timer, which will then lift the plate and mirror straight away before tripping the leaf shutter after ten seconds. Due to the particular way the release and shutter are set up on the Bessamatic (the earlier ones at least) it is even possible to use the timer for Bulb exposures to exploit the absence of vibration it will afford you (the leaf shutter will open as normal ten seconds after the timer starts to run, and stay open until the pressure on the release is eased). So the timer is a vital piece of equipment for me and it has to work. For the above reasons, I suggest checking it on any example, if tripod imaging and maximum sharpness are a part of your workflow.
On the topic of these timers, I'll suggest that, when needed many owners might not hesitate to use a slower shutter speed if the occasion demanded it, yes? Well the slow speeds use an escapement for their delay, too, and it is actually a more complicated inertia/retard type, whereas a timer escapement is just a simple retard escapement with the pallet permanently engaged. To my mind, the reason they will often stick, as found, (even in a shutter that is otherwise working correctly) is because most people never use them at all. Moral is: if your shutter is working well, and the timer runs off smoothly, you can either (a) listen to the naysayers and never touch it, (virtually guaranteeing that when it is eventually set, by design, or otherwise) it *will* stick, or (b) exercise it regularly, in which case, it should then give no more or less trouble than the slow speeds of a Synchro Compur (which will also appreciate at least semi-regular use or exercising).
A chap by the name of Mecking sells a very good repair manual on CD with actual photographs, lots of them, and excellent instructions for getting one working again. I bought one years ago and whilst I would have got mine going without it, I certainly appreciated the information and images which made things quicker and easier. He regularly lists them via eBay, here's a current listing
That's probably enough for you to get on with.