Over-Engineered and Way Too Complicated!

[Pál_K]

…
Voigtländer's Bessamatic is a delightful and effective SLR with good lenses. Arguably the most ergonomic of all the lens shutter SLRs. But needing to pull most of the camera apart, just to reach the Synchro-Compur shutter for servicing, is onerous. Even a Contaflex is much much less involved.

The Minolta SRT101 is a superb, well made and generally reliable 35mm SLR. I have several examples and rate them highly. But those pulley strings that control the tell tale circle in the viewfinder for the meter. Yes, it works, but does not match the quality of the rest of the design and is a pain in the fundament to replace.
…

About 15 years ago my Bessamatic’s shutter jammed. I knew how complex that camera was and that rear film baffle - well it baffled me also on how to get at anything inside the camera. Ten years later, by a series of referrals I found someone, someone well known in the past, who agreed to fix it. He told me that the Bessamatic was the very first camera he learned how to repair. Aside from shipping, he had the camera back to me within a week - fully functional, including the self-timer (the V* part of the MXV lever). I thanked him and asked if he would like me to mention his good work on the photography forums, but he said no because he had more than enough work and was trying to wind down his camera repair work. My Bessamatic still works like a jewel today.

Yes, the Minolta SRT-101 strings - nonfunctional shutter speed readouts kept me from buying an SRT-101 at swap meets for many years.

I once heard someone say about cars that there are two schools of design: one designs something with the assumption that it can go wrong and builds it in a way that'll be easy to fix. The other designs something presuming that nothing can ever go wrong with absolutely no thought to how repairs will be done in the future…

What’s really distressing in the software and firmware world is when you have managers who never were engineers (or at least not good ones) who have this “sunny day” scenario mindset. They concoct schedules which assume circuit boards are layed out correctly the first time, the components are populated correctly the first time, the design is flawless, board bring-up is flawless, and the firmware has no bugs whatsoever. They can’t evaluate your work correctly and rank/pay you correctly because they truly have no idea what your work involves. There are also “engineers” who design and write code without any thought of all the situations where something can go wrong. Usually their code is so bad it’s easier to toss it rather than fix it. But I digress…

* V is for vorlauf - “pre-run”

 

[Sarcophilus Harrisii]

The Vitessa RF adjustment: There was probably a special toolkit for repairman that included a special top covering with the eyepiece. I bought an extra top cover, if I ever get sucked into that again- will cut it up.

Yes, that's exactly right. A few years ago an eBay seller listed one or two such repair covers. They were cut away to provide access to the rangefinder adjustment with the cover fitted. I may well modify one myself, eventually, but I'd prefer to start with a cover in poor condition if possible.

 

[Sarcophilus Harrisii]

The Voigtlander Prominent and Polaroid 180 also have double sets of shutters. The Polaroid- first set opens as you start to press the release.
The Prominent- I flood cleaned one with sticky shutter about 15 years ago. Still works. Remember to set 1/500th second shutter speed after winding the film. It engages an extra set of springs that are too string for the auto-cocking system.

Yes the Prominents use an early version of the Synchro-Compur with a booster spring for 1/500. With the shutter set to 1/500, the tension needed to cock it is substantially greater. But if one wants the 1/500 speed, it must be set before winding on because this will cock the shutter, and selecting 1/500 when the mechanism is already cocked isn't good for the booster. Voigtländer included a manual cocking lever, so if one first charges the shutter manually, all is well, because this alleviates the strain on the automatic cocking system. (The self-timer setting should be locked out with the shutter on 1/500, so there is little danger of sliding the manual lever too far and jamming the shutter by inadvertently activating the self-timer. At least, this is how my example behaves).

 

[Sarcophilus Harrisii]

About 15 years ago my Bessamatic’s shutter jammed. I knew how complex that camera was and that rear film baffle - well it baffled me also on how to get at anything inside the camera. Ten years later, by a series of referrals I found someone, someone well known in the past, who agreed to fix it. He told me that the Bessamatic was the very first camera he learned how to repair. Aside from shipping, he had the camera back to me within a week - fully functional, including the self-timer (the V* part of the MXV lever). I thanked him and asked if he would like me to mention his good work on the photography forums, but he said no because he had more than enough work and was trying to wind down his camera repair work. My Bessamatic still works like a jewel today.

Yes, the Minolta SRT-101 strings - nonfunctional shutter speed readouts kept me from buying an SRT-101 at swap meets for many years.



What’s really distressing in the software and firmware world is when you have managers who never were engineers (or at least not good ones) who have this “sunny day” scenario mindset. They concoct schedules which assume circuit boards are layed out correctly the first time, the components are populated correctly the first time, the design is flawless, board bring-up is flawless, and the firmware has no bugs whatsoever. They can’t evaluate your work correctly and rank/pay you correctly because they truly have no idea what your work involves. There are also “engineers” who design and write code without any thought of all the situations where something can go wrong. Usually their code is so bad it’s easier to toss it rather than fix it. But I digress…

* V is for vorlauf - “pre-run”

Not sure much has changed, because years later, he's still doing some repairs. 😉

 

[Pál_K]

Not sure much has changed, because years later, he's still doing some repairs. 😉

Are we thinking of the same person?

This could be fun.

Can you provide me with a Zero-Knowledge Proof challenge to verify this? The ZK proof won’t reveal to others in this thread who it is or even the slightest clue to their name (such as a letter). Likewise, if you’re thinking of a different person, my solution to the ZK proof won’t reveal to you who I know it to be.

If you wish, I can post a ZK challenge for you first. I have a good one and it’s fun. Not only will I know whether you got the person correct, but in my verification to you, you will know whether you got the name correct and, if not, the person you were thinking of isn’t revealed to me.

 

[Shafovaloff1]

Update: Since I am learning about the Contax II shutter operation while working on them I am certain that some of the assumptions arrived at after observing what I could of operation may miss some finer points. I post to be helpful and with the knowledge that I am not a technically trained repairman on this shutter....just a person getting learned.

For the last few weeks ...on and off...I have been working on Contax II shutter(s), doing some refurbishment, a hobby. I came across a few tomes on Contax II shutters where the claim is that there is no escapement engagement at the higher speeds 1/125 to 1/1250. However, my experience is that there is no way to set up the main gear, the larger gear, having the half teeth, to avoid engagement of some gearing though there is no delay mechanism on those gears. The reason I am posting this is I have done the math and measured the distances involved and because the number of half teeth is 20 and the distance between the top of the 1/1250 slit formed at the top to the cap point with the descended 1st curtain is ~34mm there is encroachment of the 2nd curtain into the film aperture at high speeds, though the gears have no delay that is compensated by the acceleration of the 1st curtain having changing rates. The thickness of the shutter curtains alone makes this a unique mechanism. I set up a Contax II shutter without the use of the 1st curtain. That way I could examine carefully the movement of the gear and selector engagements. On all the slow speeds the escapement engagement occurs until the 2nd curtain has moved into the film aperture....approximately the same distance as the width of the leather spacer glued lengthwise on the bottom spring roller...which increases acceleration of the second curtain just before it reaches the bottom. My conclusion is that because of the acceleration of the 1st curtain at the bottom the 2nd curtain is allowed to move into the the film aperture on its way down to maintain the same exposure to light in the film aperture. Lately I have been inside because of not in best shape so have had some time to have a closer look at the Contax II shutter...maybe there is something to learn but applying math to understanding may be helping.