Mirror lenses

I have just bought a Kenlock 1:8 500mm Mirror lens (multi-coated) thinking it would be a K fit for my K1000. I now do not think it fits and wondered if anyone out there knows which maufacturer it does fit - is it Olympus? Thanks.

Many lenses of this type are some sort of T mount. You may need the pentax fit T mount adapter which should be available from Jessops and others without too much trouble. It will not be expensive.

Hi John, thanks for the quick reply. I will investigate by taking it all into my local camera shop. The back lens cover has OM printed onto it, which I assume means it is for Olympus fit cameras. Is the T mount their generic name for their brand, as the K mount is for Pentax? Just to confirm, I am looking for the T mount adapter, not the T2?

If the back is labelled Olympus it looks as though there is already a T mount adapter in place. This just needs unscrewing and a pentax k one putting in its place. A T mount ot t2 adapter amounts to the same thing. They are very simple adapters but this doesn't matter with a mirror lens, which has a fixed aperture.

John - thank you very much! I removed the screws and the adapter came off. Luckily, I have a Pentax K mount adapter. I fitted this to the K1000 and simply screwed the Kenlock lens in. Therefore, I assume it must have originally been an M42 fit. Will it now double up with the K mount adapter and a Pentax Rear Converter K T6-2X which I also have, to make a 1000mm lens? Also, since it is fixed aperture does this mean that I have to adjust the shutter speed as the only way of ensuring correctly exposed shots? Please excuse my ignorance but this is all new to me. The lens does have a type of moving, clicking Aperture ring on it - showing 8, a white dot, 11 and 16

I've never seen a mirror lens with aperture settings on it, but if you have one then they must exist! You can test this by changing the setting and checking that the shutter speed varies in the way it should. I wonder if it is some sort of rotating ring with Waterhouse stops - that is, circular openings of the appropriate sizes.

As for the converter, why not just try it and see if it all fits together properly?

Have fun!