Misbehaving aperture steps

[Tumbles]

I have an misbehaving aperture that I want repaired, and I was wondering if anyone can give any recommendations? It's in a 100mm Fujica G690 lens. The original situation was that aperture became disconnected from the aperture ring, and I took it in for a repair and it's still not working completely right. On inspection, it was found that the shutter needed a full overhaul, and who ever worked on the shutter before hadn't done a particularly good job. One thing was that there was no grease in the shutter at all.

So after the first repair, the aperture became disconnected from the aperture ring again, and fairly quickly. I took it in again, and he stripped everything down and found that a ring in the aperture mechanism had become bent. When the ring was turned all the way in one direction, the bend was causing too much friction. After a week or so after the repair, a few of the aperture steps started misbehaving. This is what the steps are currently doing:

f3.5 = not working
f4 = f3.5
f5.6 = f5.6

I could take it in again, but I have some misgivings. The main thing is my repair guy is completely swamped with work, and the shop is in tricky situation where he's left to do all the repairs himself. The disassembly is a big job, and I feel kind of bad having him do it all over again. So, I think I'd like to try someone else, if anyone knows someone who is particular good with this type of work? I'm hoping that the innards of this lens can made to be solid once again.

 

[John Koehrer]

There shouldn't be grease in the shutter except for the cam that sets the aperture and that's just a poo dab.

 

[gone]

You need a new camera or shutter, and ditch that "repair" person. They sound inept.

 

[Kirks518]

f3.5 = not working
f4 = f3.5
f5.6 = f5.6

When the aperture ring is set to 3.5, it's fully open, so you probably won't see the blades at all, so I would say 3.5 is working.
At f/4, it'll be the first sign of the blades, so if you don't see the blades when the ring is turned to f/4, then it's not working. If you see blades, it's probably working just fine.
If f/5.6, as you say, is f/5.6, then assuming you see blades at f/4, and no blades at f/3.5, then it's safe to say the lens is working fine.

The lens has a total of 8 stops - f/3.5, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32.

If you start at one end, you should be able to count 7 clicks, and see blade movement 7 times (including f/3.5 where the blades disappear, or first appear, depending upon which side you started from).

My guess, based on the info I quoted, is that the lens is working fine.

 

[Kirks518]

Forgot to say;

There are some lenses where the most open stop still allows the blades to show slightly. As I have no personal experience with the 100mm, I can't say with the utmost of certainty whether or not you'll see blades at f/3.5.

 

[Tumbles]

I've looked it over closely and the lens is wide open for certain at f4. Normally the blades are slightly visible at f4, and you can tell the difference going between f3.5 and f4. Another thing it's doing, is when I turn the ring to f3.5 and let it go, it snaps back to the f4 slot.

As, far as what I was told about the repair, I likely could not be interpreting what he told me correctly. I've done that before.

 

[Kirks518]

Could the aperture ring just be positioned wrong?

 

[Tumbles]

I doubt it. When I took it in the last time, I was shown that the post that links the aperture to the ring was flexing a lot and then slipping off the ring. The aperture itself was resisting getting turned, and my best guess is that it's doing the same thing, but only at wide open end of the aperture now.