[WendyB]

Have you had a chance to compare the SMC-K and M? I have heard that the K is a little better.

Right now, even if the IQ is similar on the two, i think that the K is going to be my next lens. The rarity, and how old the lens is make me want it! But my patience has limits...

This is true the K for some reason has a somewhat magical nuance of which for the life of me I can not explain, because optically they are the same. Anyone with out a 28mm is truly missing out.

[Canada_Rockies]

Have you had a chance to compare the SMC-K and M? I have heard that the K is a little better.

Right now, even if the IQ is similar on the two, i think that the K is going to be my next lens. The rarity, and how old the lens is make me want it! But my patience has limits...

I am going by the astonishingly good results I got for a brand new lens I bought for $110 in the late 70's. The distortion, in particular, is really minimal for an inexpensive lens. It also seems as sharp as the proverbial tack, very contrasty and great colour. I have not done any comparisons to the K version. I suspect that the K 28/3.5 and the M 28/3.5 have the same optical formula.

[clm]

Here's a link to B. Dimitrov's K-mount website:
Pentax Wide-Angle Prime Lenses

K and M f3.5 versions are completely different designs. K has 8 elements and is larger and heavier than M, which has 6 elements. So, not the same at all.

[germar]

I have 28mm in the following flavors:

Super Takumar 28mm 3.5

SMC Takumar 28mm 3.5

Pentax M 28mm 2.8

Pentax A 28mm 2.8

All of them are excellent. The Super Tak does lack that classic SMC color rendition, but that's about the difference. Honestly, all these lenses look tack sharp at f3.5, and you need to think of the extra speed on the f2.8s as a slight trade off ...a little more sensitivity for a tiny bit less sharpness. But kick them up to f3.5 and they all look really good

Which to chose? Sounds like you want to get a K mount lens, which really limits you to the M and the A series. I believe someone pointed out that these two lenses are the same formula, and my observations confirm that. If you're on a tighter budget, go for the M. If you can spend a bit more money and get the A for automatic control, I'd guide you towards that over the M. Its really nice to simply twirl the f-stop control on the camera and get what you need, or just leave it in program. It also makes candids a bit more spontaneous for me.

[deudeu]

A Mint SMC-K 28mm f3.5 is on the way!!!
I bought it off ebay. I probably could have found a better deal on it, but i would have had to be more patient... I just could not wait to have another lens to play with!
I still paid less than i would have on Keh, so i am satisfied!