Fourth Time's The Charm

Fotodiox's lens cabinet is home to plenty of fun lenses, though one in particular caught my eye: the Minolta C.E 50mm f/2.8. Some light research indicates it's the middle lens of Minolta's line of enlarging lenses (the others being a 30mm and 80mm).

Instead of using the Minolta SR (or MD) or the Minolta A-mount, it uses a threaded mount. Our M42 adapters were too big, but our M39 adapters did just the trick.

Flange focal distance would be tricky. There are ways to roughly estimate what the flange focal distance might be, but slim adapters, like our M39 to Nikon F adapter or M39 to Canon EF, are plenty thin, and glassless, too. They would be worth a try if the lens had its own focus ring.

It physically mounts, and if the goal is to make a macro setup without the inability to focus, then this is perfect! Another limiting factor that makes the combination less than ideal is that the lens recesses into the mirror box. Even my APS-C D500's mirror is too long for the lens, and it gets caught on taking an exposure:

If you're careful about mounting sequence, it could be fine if you shoot in live-view mode, since the mirror is flipped up for that, but focus is fixed at 499mm.

For a fully functioning adapter, we'd need an adapter with a helicoid, so to cut down on the flange focal distance, we hoped an M42 macro adapter would do the trick. We'd need an M39 to M42 adapter to pair it with our lens, but this would at least give us the ability to focus:

I farthest I could focus was 1242mm, so it's better than our Nikon F setup, but we have a long way to go before this is workable.

Our Leica M helicoid is the next best option that came to mind. With an M39 to Leica M adapter, the adapter goes right on:

In this case, perhaps I brought the lens a little too close to the camera. With the Leica M macro adapter full-contracted, nothing is in focus, at any range, but even at maximum extension, nothing gets sharp enough to be usable.

If Goldilocks were into photography, and in the market for adapting lenses of the lens adapting world, this is how she would feel. One solution is too long, while the other is too short. If I had to choose one, I could at least utilize the shorter option and add extension tubes as needed.

Suddenly, a mystery fourth option presented itself. It was out there, but we're no stranger to the unconventional. While digging through our more niche adapters, I found one that made me raise a brow: M39 to T-mount. On paper, this is hardly helpful; T-mount has a longer flange focal distance than the Nikon F-mount, which is already too long for the Minolta lens.

The adapter, when used with all included components, acts as a standard T-mount to Leica M adapter, which would usually add 26.95mm to our Leica M macro adapter setup. But removing the collar and the extension makes the adapter quite a bit shorter, tapering down to 13mm.

This shorter T-mount to Leica M adapter paired with our Leica M helicoid ended up being just what we needed for the Minolta enlarger lens. It took three different adapters, but it worked.