Helios lens - does it work?

Oops, sorry.

That page looks like a sensible fix.

kood produce, or did, an m42 adapter that fits flush with the body and has a flange to activate the pin.

Algernon, I have followed your advice now but used the cotton buds - these are hollow inside too and fir perfectly. I took few photos and the quality looks great. The only thing I cannot work out is the strange noise when in M mode i press AE-L button. Does anyone know what this is? It does it only with this manual lens, when I put the kit lens back, there is no noise.

Isn't it the sound of the aperture actuator? (ie stepping down the lens)
A bit of a 'zip-zziiip' kind of noise?
With the lens off you should see the lever beneath the mirror move forward to push the aperture pin.
Matt

Yes it is this kind of sound. What I cannot understand is why is it silent with kit lens? I can only hear it when using this manual lens.

It's because the kit lens doesn't need stopping down
The kit lens doesn't have an aperture ring, and the camera knows about the lens through the digital interface.

With a lens that has no digital contacts (e.g. Pentax K, or M series and M42 stuff) the aperture has to be physically actuated because the camera has no idea what's mounted. It also happens when you use an SMC-F or SMC-FA lens with the aperture ring on anything other than "A".

In fact, you can see it working - if you take the lens off you'll see there's a lever on the left side of the mirror. Pressing the stop down function will make the lever move up.

HTH!
Matt

Fantastic explanation. What more can I say. Thank you