Stuck

[Schwarzadler]

Hello all,

I'm stuck. This is a Zonlai lens, I need to adjust aperture lever (= small golden screw in inner ring) but I can't reach it. How to open lens to get to aperture blade unit and adjust lever?

[tomasg]

It s only a guess but: from the picture i can say that the aperture ring or rings are still in place on the lens body, it looks unlikely to me that you can remove the ring inside that governs the aperture (held by that brass scew you want to remove) with the external rings for setting the aperture still in place. My guess it s that you ll have to get to it from the back, try to remove the two rings with the "levers" first. I think at one point you ll be able to take out the whole aperture block and then it will be easyer to get to that screw. It s only an educated guess based on only one picture you provided, i have no experience with the lens.

Tomas

[Schwarzadler]

You are right about the ring inside that governs the aperture.
I already tried to get to the inside from the backside of the lens.
This is backside of lens. The little brass rods (at 1 o'clock and 7 o'clock positions) are connected with focus ring on the outside. They hold and guide the inside housing during focusing. How to remove the inside housing from the outside housing? Tried to turn but no movement.

[tomasg]

Ok, again just by looking at the picture, a few questions and suggestions:

The ring with the three holes in it, is the rim part of it or are they two separate pieces? (my guess it s one piece)

If you try to turn this ring is there any movement (maybe with a tool that goes into the holes), even the slightes? Is there any movement of the two brass rods?

Can the two brass rods be pushed inside (from the front), are they spring loaded?

My wild guess is that the two rods has to be pushed in and then the back ring should be free to turn. I wouldn t be surprised if as you turn it you ll find three tiny screws at one point just where the three holes are. After all why three holes?

Tomas

[Schwarzadler]

The three holes are for the screws to hold the lens mount.



There's no movement what so ever because it's one piece, as you already said. The brass rods can't be pushed in, no movement at all.

Probably the aperture lever screw (the brass screw in the inner ring) can be reached from the outside from the aperture settings ring. But these setting ring is glued on the ring where the brass screw is in and cannot be removed anymore.

[Lightshow]

A few more pictures from different angles please.

[Schwarzadler]

[tomasg]

Aha, now is more clear. The three holes are actually where the lens mount is fixed. You removed the optical block that was in front? Did it simply unscrew?

[Schwarzadler]

[tomasg]

Hm, puzzling. I always say: if you want to catch a fish, think like a fish! Or in our case think like a lens designer/engeneer. You say the aperture ring is glued? Maybe it s glued with some thread locker glue (like Red Loctite)? Once the glue is removed, with MKL or something else it can be unscrewed? I am wildly guessing now

Tomas

[Lightshow]

What happens when the lens is fully extended to MFD?
What is the issue that you need to open it up?