Aparture problems flektogon 35/2,4 and pancolar 50/1,8

!Karen · Joined: 20 Jul 2013 Posts: 837 Location: Belgium Baby

i have 2 different aparture problems for these lenses

Flektogon: the aparture opens and closes fine in the M mode between f2,4 and f8. Beyond f8 it closes further down as it should, but when turning the aparture ring back to for example f8 or wide open, it stays closed. I need to switch to A mode and turn the aparture ring a couple of times to get the aparture to jump to wide open again. There is no oil on the blades.

Pancolar: this aparture works fine except when you point the lens upwards to the sky, then it does nothing anymore. Again no oil on blades.

Any ideas on what could cause these strange problems?

TrueLoveOne · Expire: 2013-12-24

I've had a few of these DDR manufactured Jena lenses. Their build quality is not the best, unfortunately.....

You need to open them up to clean and lubricate (very carefully!) the mechanisms that control the aperture. Some springs might have lost their strenght and need to be replaced. These aren't the most difficult lenses to work on, mine worked fine again after some love and care! You do need some precision tools though.

Cheers, René!

Gonzoo · Joined: 29 Mar 2010 Posts: 232

I second René's advice. Check springs strength, relube and double check for oil/dirt on aperture blades. If they are clean you migth also want to check the aperture housing for residues that hinder the movement of the aperture.

Eugen Mezei · Joined: 17 May 2008 Posts: 265

Where do you get new springs?