I use 5400 lens at 0.67x magnification. So just project full film frame to APS-C sensor.
Corner at your example looks perfect. So it could be some problem from my side:
- Lenses are always slightly different. So this could some unlucky bug in my lens.
- It also could be due film curvature tolerance combined with my film holder.
- Seems the main problem source is my bellows. I just noticed that bellows are wobble a little bit even when lock screw is fixed. My setup is vertical, so due weight lens became under some angle compare to sensor. In optical systems this problem named Astigmatism. Guess for 24mm F3.9 reversed 5400 lens (based on closeuphotography measurements
https://www.closeuphotography.com/mi...lite-5400-lens) perfect alignment it way more critical than to 50mm F5.6 enlarger lens.
I created test shoot in horizontal position and corners looks sharper, but still not so sharp as in your example. (you can open full sized images in new tab or download them)
I use Novoflex Minolta Bellows modified with RAFCAMERA plates with M39x1 thread. This adapter was manufactured based on my idea and measurements, so you can see actual pictures of my bellows there:
https://rafcamera.com/plate-novoflex...ws-rear-m39x1m
https://rafcamera.com/plate-novoflex...s-front-m39x1f
I also use 18mm to RMS thread adapter for 5400 lens
https://rafcamera.com/clamp-18mm-to-rms-m
And RMS female to M39x1 male thread adapter with M42x1 front female thread (this adapter also was manufactured based on my idea)
https://rafcamera.com/adapter-rms-f-to-m39x1m-m42x1f
On top of that i put lens hood made from M42 extension rings.
By the way, i find interesting lens named Osawa Tominon EL 1:2,8/50 mm. It looks like some modification (or newer version?) of Tominon with wider aperture and with normal M39 thread. It should arrive in month or so and i could test it...