I think you mean Takumar Bayonet?
Originally Posted by darinwc
These were multicoated, just not SMC. Some of them aren't too shabby, others are horrible. They were sold as a cheap alternative to the full SMC Pentax lenses.
Especially don't be taken in by the 135mm f2.5, it isn't the same lens as the SMC Pentax or M42-mount Takumars but some people seem to think it's worth a lot more than it is.
Weirdly the Takumar Bayonet 135mm f2.8 is reckoned to be decent enough. I have the 28mm f2.8 (mechanically and optically identical to the later version of the Pentax-M 28mm f2.8, just with non-SMC coatings) which is certainly sharp but suffers from rather insipid colour reproduction. Use it on a bright sunny day and it's pretty acceptable, but given that you can get a Pentax-M 28mm f3.5 for about the same money now I wouldn't advise buying the Tak Bayonet lens.
In general if you avoid any lens which doesn't have "SMC" in its name you should be ok. The non-SMC ones can be fun to play around with but if your budget is tight you should aim for a smaller collection of better lenses.