Mamiya: 7 II, RZ67 Pro II / Canon: 1V, AE-1, 5DmkII / Kodak: No 1 Pocket Autographic, No 1A Pocket Autographic | Sent w/ iPhone using Tapatalk
I have a Roleiflex 2.8C, the last Rolleiflex model with 10 aperture baldes. Last year of manufacture was 1954, I believe. After this, the Synchro-Compur shutter units that Rollei used came with 5 blades.
Minolta Autocord shutters seem to have gone from 10 to 8 blades around 1956? Not certain when the Seikosha MX shutter was replaced by the Citizen. After using a couple of Autocords with 10 blades, I sold the first one with a Citizen shutter within a month- couldn't stand the different look of the 8-bladed aperture compared to the 10-bladed.
Yashica- Copal- had 10 blades into the early '60s it seems before going to 5 blades.
Anyone know when Hasselblad came out with the first leaf-shutter model? This would give some credence to the auto-aperture thing as the lenses needed to stop down quickly. Any other camera making such demands on apertures around 1954-5?
I think the Hasselblad 500c was introduced in 1957. The older lenses for 1000F/1600F indeed had round apertures with many blades. In fact the five blades is the Thing I dislike most about Hasselblad and Rollei lenses from the 2nd half of the century, though Hasselblad had round apertures at least in the 110/2 and 150/2,8.
Hasselblad/Zeiss 110/2 actually has a two-layered aperture, where the front ones a pretty typical 5-blade that are slightly curved to give you a slightly rounder pentagon, but the rear layer stop down circularly, until around F5.6. Pretty cool design.