Help to open Vivitar 28mm f2.5

[jl168]

Do anyone know how to open this front element of Vivitar 28mm f2.5 Kiron made lens? My lens has fungus inside but it seems being cemented. Your help is much appreciated.

[calvin83]

[RnR]

Can't help ya mate, but try posting down in the Repair subforum.

[Pancolart]

Front ring could be glued true. If there is a lot of fungus then try using micro saw (you don't have to touch glass), cutting ring on one part. Then you will be able to remove the ring by bending it. After cleaning you can re-glue the ring and cover the cut with some black matted clay.

[Lightshow]

I wouldn't cut anything yet.
Can you post a few more pictures from different angles? side, front & back

[jl168]

Thanks for the inputs... I am not so confident on cutting the lens.
Here comes some photos.

[Lightshow]

It doesn't look like it has any openings for an iris control(unless it's on another side) So you can see fungus in this optical block?
The only thing I can think of is just behind the front end(the widest part with the slots), that part screws on to the the part that has threads, normally they would use grub screws to keep the parts from unscrewing, maybe they used glue?


To see if the threaded sections thread into the next larger section or are solid, you can pick at those spots with a pin, a solvent(acetone? NOT ON THE OPTICS as a caution) may soften the glue if there is any.

Take your time to investigate how it's put together.

I really hate it when they use glue vs. retaining rings that screw in.
My Rokkor M 28 is glued, as is my C/Y Yashinon ML 50/2, and they both need servicing.

[Pancolart]

Acetone might be riskier then making one small cut to release front ring.

[Lightshow]

Well I wouldn't suggest soaking the lens in it, as cemented elements could be damaged, and a remote possibility the coating could be damaged.