Talk:Rolleiflex SL35 lenses

Rollei QBM III vs. QBM IV

It is quite simple to identify QBM I and QBM II lenses, but when you have a QBM lens with the crosshatched rubber grips on focus and aperture rings it is not at all simple to determine if the lens is QBM III or QBM IV.

We could provide a great service if we could help readers tell which type of lens they have. Perhaps we should start a page for that.

IIUC, the following is true.

• If a Rollei/Zeiss lens, the crosshatched rubber grips are a necessary, but not sufficent condition to be QBM IV.

• All Rollei/Zeiss 50mm f/1.4 lenses with the crosshatched rubber rips are QBM IV

• All Rolleinar lenses are QBM IV

• All Voigtlander lenses Made in Japan are QGM IV

• All Rollei/Zeiss lenses marked "Made in Germany" (NOT "Made in West Germany) are QBM IV.

Were there any Voigtlander lenses marked "Made in Germany"? It is my understanding that they were all made in Singapore or Japan.

So, this leaves a lot of Rollei/Zeiss lenses that have the new style crosshatched rubber grips with no simple way to tell if they are QBM III or QBM IV. With other brands of lenses such ad Nikkor it is simple to tell which series they are by the serial numbers:

http://www.photosynthesis.co.nz/nikon/serialno.html

Does anyone know if this would work for Zeiss/Rollei lenses and if this information exists somewhere?

It also appears to me that it should be possible to determine if a lens is QBM III or QBM IV by measuring the difference in height between the ring with the notch for Pin #2 and the next larger ring on the lens where there is no obvious notch/step in that ring near the red dot. But again, we would have to find this information

JRT256 22:42, 4 August 2010 (EDT)