I can answer about the MX-EVS taking info from Prochnow Rollei Report II and my own experience. The MX-EVS is the 3.5B for this author, he does not distinguish Type 1 or Type 2 but there are some differences within this model, enough for other authors to distinguish 1 and 2. This was the first Rolleiflex TLR with EVS system, it was manufactured between April 1954 till September 1956, there were two serial numbers blocks for this camera:1,428,000 till 1,499,999 and 1,700,000 till 1,737,999.- 94,000 3.5B or MX-EVS were manufactured. The camera was provided with three different taking lens:Tessar 3.5/75 (Carl Zeiss Jena), Opton Tessar 3.5/75 (Carl Zeiss Oberkochen), Xenar 3.5/75 (Schneider). This camera used the linear Synchro Compur CR00 MX for the EVS for the first time in a Rolleiflex. From the camera serial number 1,700,000 (starting the second serial numbers block) were introduced improvements for the EVS, f.e. the neutral or free position. For the author Evans these improvements are enough to call the 3.5B "MX-EVS Type 2" from the serial number 1,700,000.- There were three technical moments for the EVS development. We can find the first moment in the firsts 3.5B or MX-EVS Type 1 cameras, these cameras don't have the middle button in the diaphragm wheel to lock-unlock the system, these cameras are from the serial number 1,428,000 till 1,464,000 (this complete block is till 1,499,999). Some of these rare firsts MX-EVS have the word "Germany" in the diaphragm wheel, Prochnow shows a photograph in 16-358. I think this camera is rare today, the serial numbers block is shared with the 2.8C.- The second technical moment for the EVS was the central button that you need to maintain pressed to unlock the EVS, it was added from the serial numbers 1,464,000 till 1,499,999, I think this camera is well known and in general the users indentify it as "MX-EVS type 1", but really it is a second EVS evolution. Prochnow shows a front panel photograph also in 16-358.- The 3.5B "MX-EVS" Type 2 (according Evans name) has the EVS mechanism more perfectioned with the free wheel or neutral wheel position, avoiding to maintain pressed the button to unlock the EVS, this system is also used in the 2.8D, E, 3,5E and other Rolleiflex models (some Rolleicords and T also have EVS but the means to set it are different), this is a third evolution, Prochnow shows a front panel also in 16-358. This evolution started in the second serial numbers block for the 3.5B, 1,700,000 till 1,737,999.- Carlos 2014-05-18 0:05 GMT-03:00 Evan Dong <dmarc-noreply@xxxxxxxxxxxxx>: > I have a question that I was unable to locate any information for a 10 blade > aperture Rolleiflex TLR other than the 2.8C. > > I have a Rolleiflex MX-EVS Type 1 that has a round blade formation, rather > the pentagon shape usually encountered. > > What information is available for the other than a 2.8C Rolleiflex? > > > Evan Dong > --- Rollei List - Post to rollei_list@xxxxxxxxxxxxx - Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe' in the subject field OR by logging into www.freelists.org - Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with 'unsubscribe' in the subject field OR by logging into www.freelists.org - Online, searchable archives are available at //www.freelists.org/archives/rollei_list