There is a very good comparison on the other Pentax site, mainly with real photos.

The M 200 f4 is well worth the low price they fetch.

Classic Pentax M, compact and beautifully built. Definitely worth adding to you bag!

Thanks for the info Andrew.

I understand it was made with M42 and M39 mounts so I guess they were probably made so the mount was the only part that needed different tooling.
I have not had any reason to take this one apart so I don't know for sure what is inside so can't offer any suggestions as to the ease of modification. Being a preset lens there is no mechanical connection of the aperture to the camera so the mount is purely the M42 screw.

Lovely!
Looks like a super trip. They are super photos!

I must admit, I think I prefer the black & white ones. The mountain environment is often lacking in colour and monochrome often enhances the textures for me.

Tair-3 300mm F4.5 preset m42 lens for sale.
One of the best cheap 300mm options. Aperture diaphragm has 15 curved blades to give a pleasant bokeh. Comes with original case, caps and filters and In good condition.

This is the preset version of this lens so nice and easy to use on digital, with an m42 to K mount converter. This is not the Zenith Photo Sniper version so no complicated mechanics you won't want. It has a built in lens hood and tripod mount. There is a skylight and light green filter which have their own storage in the fitted case.

Photos of the lens below, along with some I have just taken with The lens on my K5.













This one was cropped a bit



This one was taken through the double glazing of the kitchen window! (was cleaned the other day)
Roof is about 75-80m away.




£55 + postage. Located in Berkshire (Newbury) if anyone wanted to pickup and save the postage.

Thought I would add a few photos taken with the lens.

I would have thought the obvious was Mounts bay, St Michael's mount.

You can walk out at low tide or take a boat from Marazion.

Still available if anybody is interested.

Some of these are really good.

Must have a try at this ICM, although I guess you need to work at the technique to get good results.

Just tried the Pentax hd1.4 converter with the DA200, on my MZs. No problem, full frame coverage.