It's a lens from the 1950s, but if you get something in good condition, it's a living thing.
— Old Lens, Forever (Japanese blog in translation)
Free-lensing. Sounds fun, doesn't it?
It's thrilling all right, but in the wrong direction. For me, it's about hoping my intractable left hand doesn't just suddenly let go and drop the lens to the pavement.
But the It Happened To Me of the lens-dropping is a story for another day.
Today I'm free-lensing the Voigtlander Skoparon 35mm 3.5, the subject of much gnashing and grinding of teeth right here on this very blog.
While attempting to figure out its flange depth in the least painful way possible, I discovered that it's close-but-not m42.
So, armed with my Samsung NX500, an M42 adapter for "structure" (the rear element nestled quite deep inside), and gumption…
I did not drop it!!
In the spirit of the original blog where I found the lens, these photos are not edited except for exposure.
Everything's cold because it was cloudy and rainy today.
It's a really lovely render. Just look at that gentle fall-off!
And it can hit infinity with this setup! But it turns out free-lensing landscapes is crappy — it's too hard to hold the lens perfectly level. The results were just too ugly to post.
Now, having shot with it successfully, it's no longer theoretical.
I'm thinking I might be able to avoid wasting the money and engineering of the tailor-made-for-the-other-lens adapter altogether.
Here's what I've learned:
- The end of an M42 adapter is too long, so a helicoid on top of that would definitely not work.
- If I go straight to the helicoid — say, 17mm-31mm — we can go from beyond infinity to quite close up. That's with the m42 helicoid's screw thread partially inserted into the throat of the camera. It has to be partially inside to get infinity.
- Maybe I could saw the ass end off the helicoid and somehow convert it to an L39… ? That, I could adapt to anything.
- Either way, I've got to somehow secure the back of the lens to the helicoid, permanently
EDIT: Duhhh, brainwave… I just searched on eBay directly and found that M42-L39 helicoids exist! Previously I could only find m42-m42, and m42-mirrorless ones. Google was "helpfully" curating the results again, I see. Well, $26 delivered is a lot less than the Yeenon adapter I was planning to similarly butcher!
One confounding factor is the internals of the lens itself; the rear element of the lens is spring-loaded, and therefore clearly meant to get pushed in, at some point. Why?
But regardless, the biggest issue is:
How to securely attach the damn thing to the helicoid?
Whatever glue (or whatever) has to be strong enough to withstand turning the lens to turn the helicoid, and of course adjusting the aperture.
Problem: I know nothing about glue (or whatever).
 I found this after some more furious googling:
"The lenses all mount in front of the shutter on either the front of the shutter itself (as in the 50mm’s) or to the body with the lens focused by the hole in the shutter pressing on a focusing ring on the mounted lenses. It’s 'different,' and as I think about it, I wonder how lenses had to be optimized, particularly the shorter ones for being so far ahead of the focal plane… The back of all lenses is literally a little tube that fits into the hole of the shutter. Focusing is done by moving the shutter closer and farther from the film plane, and the operator does this by turning the celebrated focusing knob on the left side of the camera, surrounding the rewind key."
……… why would you do that?!