My Rectimascop focusing seems irrelevant, any suggestions?

[n22]

Hey guys, this is my first post here. I do mostly still photography and I’m just getting into Anamorphic lenses since I picked up a Rathenower Rectimascop 48 out of curiosity. I love old lenses and camera’s and when I spotted this cheap it looked really interesting to experiment with.

I’ve got it set up on a set of rails and have been doing a few test shots to fine tune the focus (the rear element seemed to be out of alignment, but I’ve got it pretty good now), and generally get used to using it. My taking lens is an 85mm jupiter 9, and I’ve been fairly happy with sharpness etc, but the focusing on the Rectimascop has got me a bit baffled. Basically I don’t seem to have to focus it at all, it is always sharpest set to its closest distance, so screwed fully in. With it in this position I seem to be able to just focus with my taking lens. Whether focusing at 8 feet or infinity if I adjust the Rectimascop the image just seems to get softer. This seems counter to all I have read, I expected to have to focus both lenses.

Sharpness on mine seems reasonable from about f4/f5.6 onwards with my jupiter lens. It’s in no way crystal sharp, but really it is surprisingly better than I expected. If I could pick any issue then perhaps it is a little soft in the far distance for my liking, as if focus is a bit short of infinity. I thought maybe the rear element wasn't screwed fully in, but it is as far as I can get it and keep it aligned.

Has anyone else got any experience with this lens, and if so is this “set it and leave it” focusing normal? I’ve done a good bit of searching here and elsewhere without any success. It would be nice to know I’m getting the most out of the lens if there is any potential for improvement.

 

I'll attempt to attach a couple of test pics I took today for reference, taken with the focus at infinity on the Jupiter and minimum distance on the Rectimascop.

 

Edit: I got my Rectimascop focusing backwards, so edited the text to correct.

[n22]

Here is a couple of pics of how my lens is set up as well, just incase anyone can point out if I've done anything stupid (no clue what my thumb is doing in that first pic by the way, it's fine honest).