Minox spy cameras: How's their mechanical heart ticking?

[tjwspm]

The Minox A IIIs, B, BL, and AX use purely mechanical shutter systems to control light for their tiny 8x11mm film. No electronics — just intricate engineering! How do these cameras handle shutter speeds from 1/2 to 1/1000 seconds, plus B and T settings, to achieve perfect exposures?

This question had been nagging at me. Not just out of curiosity about how the designer had managed to achieve this. That too. But what about the Minox cameras where the shutter speeds are incorrect? This is an issue that preoccupies many Minox enthusiasts. If you want to repair it and not just blindly try things out, you need to know what's going on inside the camera.

After a year and a half of reverse engineering, I finally cracked the code of this mechanism. Since my memory isn't very good, I had to write everything down so I wouldn't forget it. Besides, some things only become clear to me when I try to put them into words. I now would like to share the result with you. My article includes many photos and videos —never before seen online or in books — showcasing the system in action. As far as I know, there’s no other technical description like this out there.



I would greatly appreciate your feedback on the clarity and completeness of the article, as well as any further suggestions on other Minox topics – please let me know what you think!

P.S. This is just my hobby — nothing commercial! I write mainly for myself, so that I don't forget the insights I've gained and so that I can share my enthusiasm with everyone who is interested in historical (miniature) cameras.

Click here for the full story:
Trigger Warning: Contains highly technical details that might send tech geeks into excitement!

The Minox exposure system

From the user's perspective, exposure consists of three simple steps: set the exposure time, cock the shutter, and take the picture. All images in this

moments-of-now.com

 

[tjwspm]

I had always been unclear about how the set shutter speed is actually transferred to the escapement. My imagination is limited, so I tried to illustrate this with superimposed photos from inside the Minox, namely here:

The shutter speed dial

The shutter speed dial on the Minox is, alongside the shutter release button, the second user interface of the exposure system, which controls the

moments-of-now.com

 

[Garry Edwards]

Thanks for posting this, very interesting and a demanding project.

I have no personal experience of the Minox sub-minature models, back in the early 60's I worked for a large Company (Wallace Heaton) that sold the A and B models and also stocked the film, in theory at least, but from memory nobody actually bought them, they were considered to be a bit of an odity even back then, there were a lot of "different" cameras, so I never actually got to play with them.

My memory tells me that the cheaper 'A' model cost around £80, equivalent to around a months' wages or £3K today, maybe that's why they weren't popular . . .

My (probably wrong) understanding of them was that they were simply pointed at a document or whatever, at a fixed distance of about a foot, aided by a little silver chain of the same length, and took the shot.

I'm guessing that your interest is in the mechanics, but if you're interested in spy cameras, although very different, shortly after that I worked for James A Sinclair, they hand-made 35mm cine cameras for underwater use, with the unique facility to remove the film underwater, leave the camera on the seabed (or in the Russian harbour). They were supplied to just one customer

 

[swanseamale47]

I never had one myself, but I do remember using my fathers (he had a couple) I liked the pocket size and the image quality seemed pretty good for a small camera.
Never really thought about how they worked until now.

 

[StephenM]

That was very interesting Garry. Being curious, I just consulted an old (winter 1960/61) copy of Photomart, a listing of equipment and prices. The Minox was £79/12/7 (£79.62). In my copy of the Wallace Heaton Blue Book for 10 years later, the Minox B was £121/9/3 (£121.46).

Edited: 10 years later, not 20. That was year inflation on my part.

 

[tjwspm]

I never had one myself, but I do remember using my fathers (he had a couple) I liked the pocket size and the image quality seemed pretty good for a small camera.
Never really thought about how they worked until now.

These cameras take actual pictures in amazingly good quality. Here are some examples I took with different Minox models:

Gallery

Behind the images shown here is the concept of the present. They reflect the brevity, the fleetingness but also the decisiveness of the moment. They don't want to show the beauty of the world, nor the ugliness.

moments-of-now.com

 

[tjwspm]

That was very interesting Garry. Being curious, I just consulted an old (winter 1960/61) copy of Photomart, a listing of equipment and prices. The Minox was £79/12/7 (£79.62). In my copy of the Wallace Heaton Blue Book for 20 years later, the Minox B was £121/9/3 (£121.46).

Yes, they were very expensive back then. In 1950, the Minox A cost 1.3 times the average monthly salary in West Germany.

 

[Cannyekerslike]

Yes, they were very expensive back then. In 1950, the Minox A cost 1.3 times the average monthly salary in West Germany.

 

[auntiemaryscanary]

For comparison you can buy a used one from ehe US for under a £100. There is one on eBay for £150 from a UK camera seller. I think I paid about a £100 for mine in a MS Hobbies sale.

IF you are looking to buy one it's worth noting they are also known as the "iii" and "iiis" with the "s" denoting it can use a flash I think.

Very capable camera for general photography too.

 

[tjwspm]

If I were to buy my first Minox, I would choose a Minox B. They are more widely available and cheaper to buy. Here are a few tips for buying one:

Minox for beginners

Which Minox camera? How do I get Minox film? Film development? How do I take good Minox photos? Digitization? Post-processing?

moments-of-now.com

 

[auntiemaryscanary]

I

If I were to buy my first Minox, I would choose a Minox B. They are more widely available and cheaper to buy. Here are a few tips for buying one:

Minox for beginners

Which Minox camera? How do I get Minox film? Film development? How do I take good Minox photos? Digitization? Post-processing?

moments-of-now.com

Yes the in-built light meter helps on the B which is basically an A/iii with a selenium meter stuck on. The "easiest" to use is the EC but that brings with it electronics and no manual control over shutter speed bar flash setting.

 

[tjwspm]

I

Yes the in-built light meter helps on the B which is basically an A/iii with a selenium meter stuck on. The "easiest" to use is the EC but that brings with it electronics and no manual control over shutter speed bar flash setting.

Yes, exactly. Personally, as a minimalist, I also find the Minox A cooler, but when you're just starting out, the B will do.

The EC is the cheapest option and you can try out the entire 8x11 workflow with it. But as you say, you're stuck with the electronics and the initial aperture of 5.6. On the other hand, I think that if the conditions are right (distance and sufficient light), the EC can produce photos that are technically at least as good as those taken with the “classic” Minox.