Originally posted by Canada_Rockies You can choose Takumar manual, Takumar preset, Super Takumar, the latter with or without Super-Multi-Coating, S-M-C, S.M.C. or SMC. The advantage of lenses with the smc, however engraved, shows when shooting with bright light sources in the field of view. With the sun at your back, and no mirror in front, the difference is minimal.
On the other hand, some like the look of the less coated, or even uncoated lens, the original soft focus effect.
More than coatings come into play however. I have a torture test that I did a while back, and will someday repeat: we have a Sony shortwave radio on a windowsill, with a window screen a couple of inches behind it. Heavy backlight and OOF screen. In my earlier testing, the better lenses were the 43 and the 55... the two 50's just fell apart.
Now some of this has to do with the interaction of relative distances and the focal length of the lens.
In general, the statement that better coatings result in technically better photographs is true.
The effect of uncoated or single coated lenses isn't precisely soft focus, to my eyes anyway. Rather there is a bloom to light - a sort of haze flare - that is highly esteemed by many. A good effect to understand and use when one wants to. (Many Leica lenses cost a ton of money, used, due to this haze effect.)
My position continues to be: Pentax did us all a favor by having the same/similar lens in Auto, Super, and SMC versions, as we can now justify having multiples!