James, Judging by the serial number your lens should be a QBM IV - my sequence of numbers is: ROLLEIFLEX SL35 ROLLEI 50MM F1.8 PLANAR GERMAN 1034892SL ROLLEIFLEX SL350 ROLLEI 50MM F1.8 PLANAR 5509368 ROLLEIFLEX SL35M ROLLEI 50MM F1.8 PLANAR 1222027 - this is a lens purchased later so without checking is probably a QBM IV ROLLEIFLEX SL35ME ROLLEI 50MM f1.8 PLANAR 1032003 with the following being QBM IV lenses ROLLEIFLEX SL35E ROLLEI 50MM f1.8 PLANAR 1207367 ROLLEIFLEX SL35E ROLLEI 50MM F1.8 PLANAR 1285673 ROLLEIFLEX 3003 ROLLEI 50mm f1.4 PLANAR 3120650 If there is a recess and a lip, I think it is QBM IV. From memory (my lenses are not in front of me) on the earlier lenses it is not so much as a sunken ring as a 'cap' which has no recess. If your extension tube gives an aperture reading, something is out of adjustment. Because there is no aperture connection between lens and camera body, there can be no aperture information displayed in the viewfinder. This would then explain why your lens does not show up in the viewfinder unless it is actually a QBM III What happens with your 60mm Makro? Does the aperture reading show and then change if you gently press the pin on the camera? The only other thing is the black 'stop-down' button below and on the right of the lens - opposite the red lens release button, could be in stop-down mode. To check, remove the lens and press the button. If in stop-down, the 'flap' at the bottom of the lens opening will be out; in automatic mode the flap will be retracted. But I expect you know that anyway. My Prochnow book is at home and I will check tonight but I expect Carlos will have his to hand and can check the photographs of the rear of the respective lenses before I get home. ;-) John On 18/08/2010 19:14, "James Richard Tyrer" <tyrerj@xxxxxxx> wrote: > My lens came yesterday and I seem to have a problem. The LEDs on the > right of the VF do not indicate the aperture. They do work if I use the > 30mm auto tube (which is for the 60mm macro planar -- couldn't resist a > bargain) which the camera thinks is a F/2.8 lens. > > This is a new type 1.4 lens with the cross hatched rubber grips on the > focus and aperture rings. > > Any suggestions? > > -- > James Tyrer > > Linux (mostly) From Scratch > > --- > 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 > --- 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