Personally I dig this weird little fella
It’s an old Soviet 16mm film projector lens adapted to a different vintage lens’s helicoid then adapted to Micro 4/3.
It’s a 50mm f/1.2 lens and it takes some weird photos. It’s not perfect (especially if the area is well lit) but it takes some interesting photos with a little practice.
Edit: And being a lens made for 16mm film it takes pictures just like a normal micro 4/3 50mm lens would.
I can’t say I have a single favourite, as it depends on situation, but I’m really loving my Nikkor ai s 300mm on my GX9. Aside from being the nicest manual focus I’ve had the chance to try, it takes beautiful shots. I’ve a couple of the obligatory Helios 44s that I’m servicing, but more interesting to me is the Helios 28mm. I have two of them, one made by Cosina I think, but the other is a rebranded 28mm Tomioka. I’ve seen the Tomioka-labelled one go for about 5x what I paid! With a speed booster on the GX9, that takes some really characterful photos.
Can you tell me a bit more about the adapter for the projector lens? That looks really proper, and I’ve been thinking about doing something similar with an anamorphic projector lens. I’d like to see some of the photos it takes too - are there any on your profile?
Unfortunately I don’t know much about the helicoid (the focusing part), it was already installed when I bought it from the seller on eBay. Though the helicoid has a very worn “Made in USSR” on the side.
But the last part that adapts the helicoid to Micro 4/3 is a pretty cheap and easy thing to get on Amazon or eBay as long as you know the mount you’re adapting from. In this case it was also installed by the seller in my case. Though I have bought those adapters (m39 and m42 to Micro 4/3) for other lenses I have.
I’ve shared a collection of stuff that I can share right now in another comment here highlighting some of the pics it can take, and a cool example of how it can focus on objects behind what’s in front of the lens.