Hi everybody -
I recently bought a Kipon Baveyes 0.7x focal reducer for my Mamiya Sekor C 645 lenses. The 80mm was the lens I was most excited about as with the speedbooster it should match one of my all time favorite lenses: a Canon FD 55mm. Funny enough all the Mamiyas felt much longer than what I would have expected. The 35mm should match a 24, the 45 a 32 and the 80 a 55.
To verify my suspicion I used a PL to LPL adapter, which would allow me to quickly swap from the LPL Kipon focal reducer to my rehoused Canon FDs.
Here is what I found:
As you can see the Mamiyas are significantly tighter. In fact the actual crop factor/focal reduction seems to be closer to 0.8x.
Which means the 80 isn't matching a 55 but rather 64mm and the 35mm isn't as wide as 24mm but much rather matching a 28mm.
Here is a full write up with more samples (both from me and also shots from other lens tests):
http://brooklynaerials.com/blog/2022/8/7/calculating-kipon-baveyes-true-crop-factor
This seems to be a pretty big deal and very misleading advertising on Kipon's end. I am surprised nobody else has pointed this out (at least I could not find anything along those lines).
I'd be curious if this is the same for the other KIPON Baveyes adapters like the LPL to Hasselblad V Mount or the Baveyes focal reducer made for RED DSMC2.
Let me know what you think and if you've seen similar discrepancies with focal reducers.
Cheers!