[f8orbust]

A couple of days ago I was searching through my local camera shop bargain bin and found an SMC 135.3.5 in beautiful cosmetic condition but it had oily blades and the aperture was very slow. I bought it for £5.

My original intention was to cut off the protruding part of the aperture arm, so that open aperture metering would no longer work, and thought by doing this it would turn into a screwmount type lens with full av metering, just like a Takumar.

Then I thought this lens is too nice to damage in such a way, so beer in hand I plucked up the courage to take it apart and clean the blades with lighter fluid. I didn't know how easy this would be but under half an hour later I now have a fully functioning SMC 135.3.5, for a fiver.

My question is, if I did cut the aperture arm off, would it have worked at all apertures in AV mode, like a Takumar?

Thank you

Phil P

[epqwerty]

The problem is that with the oil on the blades eventually the blades will stick all together and the aperture blades will not move all together.

[excanonfd]

A couple of days ago I was searching through my local camera shop bargain bin and found an SMC 135.3.5 in beautiful cosmetic condition but it had oily blades and the aperture was very slow. I bought it for £5.

My original intention was to cut off the protruding part of the aperture arm, so that open aperture metering would no longer work, and thought by doing this it would turn into a screwmount type lens with full av metering, just like a Takumar.

Then I thought this lens is too nice to damage in such a way, so beer in hand I plucked up the courage to take it apart and clean the blades with lighter fluid. I didn't know how easy this would be but under half an hour later I now have a fully functioning SMC 135.3.5, for a fiver.

My question is, if I did cut the aperture arm off, would it have worked at all apertures in AV mode, like a Takumar?

Thank you

Phil P

That's a nice find and even better, an easy fix to get fully functioning K135/3.5. I guess there is no auto/manual switch on the lens - when you had the lens apart was there a way to remove the diaphragm actuator arm and be able to reverse it if you choose to do so later on? If you cut off the arm you will definitely affect the resell value but yes, removing the arm should give you stop down metering (Av mode). Cutting the diaphragm actuator arm and permanently disfiguring a fine lens seem too much of a waste.

Now that the K135/3.5 is working as it should, you should be able to make a tidy profit over your initial investment. Perhaps you should sell the K135/3.5 and replace it with something like CZJ Sonnar 135/3.5 or the Jupiter 37A 135/3.5, both of which are very sharp lenses and shoot in Av mode only.

Thanks,

[Just1MoreDave]

The aperture lever doesn't come off easy in the lenses that I've seen. It's often an integral part of the same mechanism that moves the blades when you turn the ring, which you want to retain. It's the same kind of problem you run into changing mounts, with the added difficulty of reversability.

[f8orbust]

Thank you everybody. Very helpful. ....and you have given me an idea.

I find quite a few manual focus 'broken' K mount lenses (though rarely Pentax - they don't break do they?) in my local photography shop bargain bucket, ranging from £0 (if you buy something else too) to £5 max. Many of these have stuck apertures, bent actuator arms etc etc.

ps. I tried the ex oily K135 today. Very nice lens

Thank you again

Phil P