I posted the question a few months back and did not hear any helpful respond. Please allow me to try it again with a different entry. I got this Carl Zeiss 50mm/1.4 for my Contax RTS that is in need of repair of its aperature. I am pretty certain something got loose and the aperature does not close down accurately when shutter is fired. I diassembled the rear portion of the lens to examin the aperature linkage and determined that something inside is too loose that has caused the linkage to operate in a very sloppy manner. I believe I need to reach the aperature assembly to find the loose screw or something to tighten it. I must disassemble the lens from the front. I am quite handy and have done an aperature repair for a Pentax 135mm lens successfuly not too long ago. I know I could buy another one for around $200 and a repair bill of this one may be over $100. I am willing to take a chance to DIM as this one is a spare. I have another one near mint so if I screw up I still have a perfect one. I did manage to find a single sheet of disassembling/assembling instruction of this lens from an old service manual. The first line it says "unscrew filter/name plate ring (one assembly)". Does anyone know more exactly what it means? A Pentax lens has a name plate ring that can be unscrewed off. Then the filter ring can be removed by unscrewing 3 screws that holds it in place. The name plate and filter ring are two separate things. For the Zeiss 50mm/1.4 does it mean the name plate ring is not a separate thing but a part of the filter ring and can not be unscrewed and removed from the filter ring? By carefully examine the name plate ring with a high power magnifier it seems to confirm that it can not be unscrewed. I tried and it wouldn't unscrew. Now I guess I need to unscrew the filter ring and forget about the name plate ring. Does anyone know how this should be done? I will buy a 55mm flexiclamp from Micro-Tools if this is the right tool to do the job. Should I turn it clockwise or counterclockwise? I believe if I get the filter ring unscrewed everything else will be easier as the instruction sheet does list the steps of doing so. I will be very careful not to disturb the focus alignment and all glasses should be removed in its own group (front and rear group) and not to disturb the optical alignment. My number one question is really how to remove the filter ring for this lens. Any help is very much appreciated. Thanks in advance. Dave
Thank you for the pointer to the cdegroot web. I have been there and got no answers there either. Seems to be a simple question that has no answers.