[Lukas Rothe]

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Hello everyone,
I've recently bought a soligor 200mm f2.8 lens and it seems like the lens is stuck wide open. When I move the aperature ring the lens doesn't close down. Other than that the lens seems fine (It focuses fine). Could you all help me out a bit as I haven't repaired a stuck aperature ring? What are the rough steps that I need to do and do I need any special equipment? Are there also maybe websites where this is explained in detail?

Thanks for helping
Cheers

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[MossyRocks]

I had a couple of lenses with slow apertures and there it was grease that had migrated out and gummed up things. I removed there the problem was grease was coating the aperture lever coupling. I used a bunch of q-tips and naphtha to clean that up. If I remember all I had to do was remove the mount and since both lenses were just the original K (K 35/2 and K30/2.8) it was really easy. Since that lens is the simple K I would start there and see if things are just gummed up. When taking things apart take pictures before you remove something so that you know how it goes back together.

[shyrsio]

Same as the previous post, you, will need to get to the heart of it and deal with the aperture mechanism. the best way would be total disassembly, cleaning and then reassembly. But you could also try to unjam them in-place, by dripping lighter fluid or even wd-40, If you can isolate its flow.

[marcusBMG]

+ 1. remove mount to access the iris, solvent may be sufficient to free it up in situ. if not then full disassembly is necesary ...
My post on cleaning the kino made 28mm f2's is indicative (but thats a relatively straightforward example). Also the vivitar 70-210mm.
Suitable solvents: naphtha, lighter fuel, coleman fuel/similar; electrical contact cleaning spray; ether. NOT acetone, MEK, WD40.

[Lukas Rothe]

Quick update: so I've removed Aperture ring and mount. How do I now remove the back lens element to access the Iris? There was some greace around the aperture ring, which I removed, but when I turn the aperture lever the Iris still doesn't close down.

[Bob 256]

If you're able to turn the lever which directly attaches to the iris and the iris doesn't close, it's something else other than gummed up iris blades. Normally, in KAF lenses, the lens uses a mechanism which keeps the iris fully open while the lens is attached to a camera until a shot is taken. Then, a small actuating lever at the rear of the lens which the the camera has engaged, closes the lens to the set value (either determined by the lens setting, or by the camera if the lens is set to its AF position on the f-stop scale) during the exposure. After the exposure, the lens is returned to its full-open condition so you get full illumination for viewing and AF functioning. You might want to look there to see if this mechanism is working properly. Perhaps that lever is jammed somehow in the full open position (opposite position to what is shown below).

[marcusBMG]

That rear group may well unscrew as a unit. There are two notches on the end for a lens spanner. However I wouldn't be too surprised if only the end light baffle unscrewed. Look at it closely to se if there are clues as to how it all fits together.
A drop of acetone at the joint can often help to loosen thread locker. And try warming on a radiator or with a hairdryer/hot air blower. These were put together in a manner to reduce the possibility of coming loose, so are often tight/difficult to shift!

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Last edited by marcusBMG; 01-22-2022 at 10:17 AM.

[.a.t.]

. . . What are the rough steps that I need to do and do I need any special equipment? Are there also maybe websites where this is explained in detail?
...

In addition to the good advice already given, for general lens maintenance & repair this site has some helpful information:
https://richardhaw.com/lens-camera-repair-fundamentals/

And I'm currently cleaning my own M42 mount Soligor GS 200 f/2.8.
For tools, I'm using small, flat blade and J.I.S. (cross head) screwdrivers and a curved lens spanner wrench - such as this one:
Professional Curved Spanner Wrench Camera Lens Repairment Opening Tool | eBay

Here are some details from my own disassembly. To access the iris from above:

Rotate the focus ring to minimum focus distance. On my lens there's now one screw visible in a collar above the focus ring. Loosen the screw a couple turns. Now the threaded collar will turn left and unscrew from the upper barrel. The collar should then slide down inside the focus ring.

Now you'll have access to three screws which hold the upper and lower barrels together. Loosen the three screws and the halves separate. The iris is now accessible from above.

To remove the iris for a thorough cleaning, loosen three small screws in the iris retaining ring. Now a spanner's pointed tips can unscrew the retaining ring via the two holes in the ring.
My curved spanner was needed for this step because my normal, straight spanner wouldn't have been able to reach the retaining ring holes.

If you simply want to go in from the rear, as noted already, a spanner will unscrew the rear element group.
Here are some alternatives if you don't have a lens spanner:
Spanner wrench substitutes - PentaxForums.com

If cleaning the iris while it's inside the lens with some lens elements still in place, I'd put lens cleaning tissue behind the iris to prevent solvent drips or spray from getting onto the elements.

I've owned several Soligor GS lenses which have had an oily iris, so I think it's common. By the way, "GS" isn't written on my lens, but the lens box and literature describe these lenses as GS.

Anyway, because of the nature of these GS lenses, I'm going to fully dismantle my lens and replace the old grease in the focus helicoid with fresh grease which shouldn't be as likely to migrate to the iris. I can take photos if it would be helpful.


Edit: If the problem is in fact oily iris blades, I'd recommend just trying to clean the iris without removing it from the barrel.
I took the iris out of my lens for cleaning and it was a hassle to get it back in place properly.

[Not a Number]

From the scratches on the finish I'd speculate the lens has been worked on before. Hopefully it was improperly reassembled and not damaged beyond all reasonable repair.