Carl Zeiss Jena 35mm f/2.4 Flektogon aperture system cleaning
The CZJ 35/2.4 Flektogon is quite the easy lens to disassemble. At least to the part where you have the aperture assembly removed. For instructions on how to clean the aperture blades, please refer to Andy Brown's guide to disassembling the 135/3.5 Sonnar. The 135/3.5 Sonnar shares alot with the 35/2.4 Flektogon build-wise. The main difference would be that you have to remove the focusing grip to really get to the aperture assembly. .

This guide is brought to you by Lasse Uusilehto. If you have any questions, e-mail me at l.uusilehto@gmail.com

lens step1 Step 1:
Unscrew the three screws as shown in the pic above to separate the lens mount/aperture selection block from the lens body.
Non-electric version of this lens does not have the gold-coloured pins or some of the screws. step2 Step 2:
Lens mount/aperture selection block removed. step3 Step 3:
Remove the rear lens element assembly by unscrewing it from the aperture assembly. step4 Step 4:
Unscrew the three screws shown in the picture to remove the aperture/front lens assembly. step5 Step 5:
Unscrew the front lens assembly from the aperture assembly. step6 Step 6:
Done. The part that will most likely need some touching up, is the aperture assembly. I will not get into the disassembly of the focusing barrel.