Dai: as I recall 54 cm, you do the math for 12-finger humanoids!
I have several Minolta casettes, I'll go through them and decide what i *need*. But don't hold your breath! (you have only one casette? see how mankind has stooped, back in the day you where RICH if you had one!!!)
I was lucky when autofocus SLRs was introduced, Minolta made a huge succes at the time, and the local dealer was grabbed by a younger, more eager..... When he started to sell his new models, some older SLR came to the light, and lots of stuff for the Minolta 16's, at the time I was recently divorced, and very, very poor (!!) but I managed to get at least one of each of what was in the boxed, close focus lense and so forth.
I bought a Minolta 16 -II back in 1972, I still have the camera, and quickly got a set of close focus lenses for it. I used that camera as my day to day notebook for a couple of years, used 16mm USAF guncamera B&W film and cut that myself in a darkroom to - yes! 54 cm. It was a very cheap form of photograpy, it cost me 1/7 cent per negative developed and archived, I still have all of those negatives... and a few Kodachrome & Ektachrome slides.
I say that my Minolta 16mm was pre-diugital, digital cameras, I aleways carried a camera, like todays mobile phone, and was free to photograp anything and take as many frames as I wanted, since it cost next to nothing.
At one point I started documenting old telegraph poles, the old ones where lovely! God beuatiful grainy results that made Tri X look like something out of the kindergarden amd ALL those telegraph poles are long gone now, since all have been digitized! I trhink I could get rich just writing an illustrated bokk about old telegraph poles!
I'll look through my old Minolta casettes, develop the films in cafenol (finegrain developer!) and see if the casettes are still useable. But don't hold your breath, I also have a life to live and take care of!