[Boker]

Have the m42 version,would like to change to the m version if they have the same glass,if so I would like to get the m version.Trying to do away with my m42's and adapters.

[Just1MoreDave]

It's not the same. The M is smaller, 52mm filter vs. 58mm on the Takumar. The SMC Pentax 1:4 200mm is the same optical formula as the Takumar. These lenses don't show up that much - you see the 300mm/f4 but not a lot of 200s. The SMC Pentax-M 200mm f4 is fairly common, though, and not that expensive.

[Boker]

Thanks,
Will plan on getting the m 200.Like to use the 200 with extension tubes but it is heavy to carry around.According to the database it is 5 oz. lighter,thanks for pointing this out.

[lytrytyr]

The M200/4 is good, but does not seem to be quite as good as its K and M42 predecessors.
The compactness and lightness of the M200/4 have their price.