Lens Conversion Fundamentals – the Mount (Part 1)

When I made my first conversion, the Canon Sureshot, I used a inexpensive LTM to M-mount adapter from eBay. These can be had for less than $10 shipped to your door and are generally good but you really never know. Of the 10 or so adapters I have purchased, two had slight issues – one had a thicker than spec lip that worked with Leica cameras but not some M-mount to Fuji adapters (for digital use), the other had the frameline flange lip slightly off (which required a tiny bit of filing). For a quick conversion, these adapters are a great fit (no pun intended). I can quickly 3D print a spacer and epoxy the adapter on it to make a solid and serviceable conversion. Such as this Lomo Smena 40mm F4.

I knew eventually I would need to graduate to something more robust and conversion specific – a custom machined mount. Doing this important part from scratch is the apex of conversions as it gives you total control of the look and feel of the final product. This is especially apparent on extremely compact lenses where the use of an adapter poses additional challenges due to thickness.

Story time

When I did my first two Color-Minotar conversions, I took the shortcut and used adapters. The prototype was rough and I just sandwiched a thin aluminium ring onto the adapter. This was thick and meant that the recessed aperture markings were obscured. Good enough at the time (for the prototype) as the aperture was accidentally epoxied shut! For the second conversion, I learned from my previous mistake and machined off the flange from the adapter so I could epoxy on the thin ring directly and therefore have a finished product that was functionally perfect.

A Super Compact Combo!

It was a fantastic lens for street and travelling so I used it extensively on a trip to Florence, Italy. Taking one of my favorite shots of the trip, even with the shoddy scan and watermarks.

Duomo di Firenze

Apparently other folks thought so too and I was able to sell it! I was very proud that I could fund my hobbies further, though I was really missing the lens. Fate would have it and a year later, I went on a trip to Budapest, Hungary, where I found a few more donor Minox cameras. This time, I figure I should step into to the big league – fully machine a conversion mount! I will need to do it eventually to tackle more challenging lenses.

To be continued.

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