I perceived a lack of organized info about the Rolleiflex SL 35 different models in the web and wrote a blog about them, I used brochures and my own photographs to illustrate the text; f.e. if you don't know why Rollei abandoned the original SL 35 development to adopt cameras based on older Zeiss Ikon/Voigtländer designs, read my blog, I also clarify some wrong ideas you can read in the Web about every camera of the system (I don't include the SL 2000 and 3000 cameras, they are for other blog, but I mention them for some purposes), I explain in detail the QBM bayonet variants among other things. BTW Herr Claus Prochnow books, Rollei Report III and IV specially, are one of the sources for the work, but there is a lot of info from other sources too. I have included a quote from Marc's book about the exact Leica Thread Mount size in the Rollei QBM adapters consideration. I apologize for some grammatical error in advance, text is pretty large (opinions and corrections are welcome of course): http://rolleiflexsl35system.blogspot.com/2011/06/rolleiflex-sl-35-system.html Carlos PS: I have the 3.5F loaded with film and the SL 66 loaded with my last TXP 320 220 roll, I'll return to practical MF photography soon. --- 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