Best M42 and K-mount lenses?

cigrainger · Apr 22, 2007

What do you guys think? I'm trying to build up a collection of glass for my Pentax K100D and forthcoming K1000 and Spotmatic (SPII or F, haven't decided). I'll use a M42-Kmount adaptor as well.

I'm looking for a reasonable telephoto prime (thinking about 135m?) maybe another standard prime (40mm possibly? anywhere between 40mm and 55mm), a wideangle (either 28mm or 35mm), and a macro lens (preferably longer, like a 100mm macro).

I'd like each to be as fast, sharp, and contrasty as possible. Fast is important especially on the telephoto because I may use a 2x teleconverter to get some extreme telephoto with my K100D, and also because I like good bokeh (same on the standard). Fast isn't as important on the wide angle, sharpness is most important to me there.

reshp1 · Apr 22, 2007

This site has some user comments on various Pentax lenses.

http://stans-photography.info

xfloggingkylex · Apr 23, 2007

being a fast lens isn't the only thing that provides nice bokeh. For a real smooth look like that of the limited lenses, you need more aperture blades (9 on most limited's)

But, having just now got into photography I cant tell you what lenses are the best and which aren't because my experience just isn't there.

cigrainger · Apr 23, 2007

Thanks for that website, that's tremendously helpful and is the kind of thing I'm looking for.

Floggingkyle, I'm well aware that nice bokeh is the result of more things than just speed, but what I meant was that at 135mm (or a 135mm being equivalent to approx. 200mm on a digital), you're not going to get sweet bokeh cutting out a bird, per se, at like f/5.6. You know what I mean? It also means that in lower light conditions, you can more properly follow the 1:1 shutter speed to focal length rule of thumb.

From my understanding, it also tends to be that early SMC-Pentax A/M and Super-Takumars had at least 6 blades as a matter of course. And 9 blades is rather high number as a "minimum requirement" for nice bokeh, if I'm not mistaken. Here's an example with my SMC-Pentax M 50mm f/1.7. It has 6 blades:

I've just gotten heavily into photography as well, so I'm not here to argue.

Steph · Apr 23, 2007

Pentax SMC, 50mm f1.4 (M42). Very fast, sharp and contrasty.

Don Simon · Apr 23, 2007

I agree with Steph on the faster prime; a Pentax f/1.4 would do nicely - in the M42 mount the Super Takumar, or for the K-mount the 'A', 'F', or 'FA'... The only one to possibly avoid would be the 'M', since I believe it doesn't reach it's sweet spot until stopped down quite a bit compared to the others.

Personally I would be inclined to stick with K-mount lenses for the sake of convenience. The M42 lenses do meter with the K-mount bodies and from experience I know it can be done, but it can be a pain having to play around with adapters in order to change lenses, especially 'in the field' or with subjects waiting for you. Similarly I would tend to avoid 'M' lenses - those without an 'A' on the aperture ring - unless they are particularly cheap. Again they can be used, as you've demonstrated... it's just often it's nice to be able to work faster and meter with open-aperture.

reshp1 · Apr 23, 2007

ZaphodB said:
Similarly I would tend to avoid 'M' lenses - those without an 'A' on the aperture ring - unless they are particularly cheap. Again they can be used, as you've demonstrated... it's just often it's nice to be able to work faster and meter with open-aperture.

I agree with avoiding M42 mounts for the sake of metering convenience, but with the M lenses I think Pentax implemented some nice features that make using them very easy. You can automatically "zero" the exposure by pusing the AE-L button, it's basically like Av priority mode with an extra button push. Or, you can pull the DOF preview lever and camera stops down and you can get a meter reading and manually set shutter speed. In both cases, it's just one extra button/lever to push. Obviously, if you can find the A for roughly the same price as the M, get it, but from what I've seen the A's go for roughly twice as much, sometimes even getting up in prices comparable to the new FA lenses.

Anyway, that's my 2 cents