Originally posted by bassek My lone K lens (K35/3.5) has the same build quality as my M's (50/1.7, 85/2, 100/4, 135/3.5 and 200/4) both are better than my A's.
All my KMA-lenses are good enough for the purchase price by far.
Hi Seb,
I don't have the K 3.5/35mm, but I'm sure it's great.
My considerations are based on the wonderful performance of my 3.5/28mm, the two lenses are quite similar in concept, if not in design.
Both are held in high esteem by knowledgeable pentaxians, and both are relatively slow, and work more than decently wide open, from what I read.
Other lenses of the same vintage had faster max aperture, but it really was meant for easy focusing in low light, more than for actual use.
That leaves the door open to a creative use of their "flaws", but I'd say that normal and short tele focals are more likely to be used that way (unless the wides are focused at very close range, or the photographer looks for some nice flare).
It's really amazing to see how rather inexpensive lenses, released more than forty years ago, still perform at a very good level, matching modern FF zooms
It is true that zooms have AF, give proper EXIF, and don't need the green button procedure, but it is also true that K and M prime lenses are sturdier, easy to transport and work great in manual focus.
I'm happy to see that some answers to my original question have given a twist to this thread. Some have shared their personal preferences, across different Pentax series, for each focal.
It's an interesting development. When I read that kind of posts I try to rationalize WHY.
Most times it makes perfect sense, thinking (or checking, my memory/knowledge is not so great...) of the lens design. A couple of times it didn't, but I don't find it so surprising, each lens design typology has both good and not-so-good examples, and ALMOST identical layouts could perform in a completely different way. A simple Cooke triplet can be quite sharp (Zeiss Triotar), be softer and give strong bubble bokeh (Meyer Trioplan), have a nice bokeh with no bubbles at all (Feinmess Bonotar), or be completely unpredictable, often with terrible IQ, sometimes quite good, due to the extreme sensitivity of the Cooke design to assembly tolerances (Meyer Domiplan).
I think an often overlooked quality of vintage Asahi Pentax lenses is their consistence. Unless a lens has been damaged, or butchered by a botched repair attempt, the variance between different examples seems to be quite low. I guess they took good care of the assembly process, had competent workmanship, and engineered the barrels in a rational way using high quality build standards. I also guess they had an efficient quality control.
You can feel it using their objectives, after so long time.
This kind of mechanical quality is praised by many users of other camera systems. Plenty of raving reviews of the "feel" of Takumar and early Pentax lenses, on the Web!
If other users share their favorites (if some K series stands in the first, most favorite line), I might try to give it a thought myself....
Originally posted by sibyrnes Thanks for that link.
I'm a huge fan of the K series. Just a word of warning to those considering purchasing a K series lens - plan on adding an additional $50.00 to any price you see because the lens will probably need a CLA. Three of the last K series lens I have purchased had sticky aperture blades.
I don't think it is so common. Probably you have been quite unlucky
I never had the same problem, maybe just a little sluggish towards the end, but I almost never shoot in diffraction zone. Though I am aware that the 28mm M sometimes has sticky diaphragm leaves.
I have seen plenty of sticky leaves, often completely frozen, collecting large format lenses. Leaf (central) shutters are very prone to it. Almost always it's the shutter, not the diaphragm. The two set of leaves sit close one to the other, and while the diaphragm leaves are manually actuated both ways (like in preset objectives), the shutter leaves are shut back by a spring. Unfortunately shutter leaves are very thin, and a tight fit, so that with a minimum of oil their resistance can't be won by the spring.
Sometimes it's possible to clean them with some Zippo fuel, a pair of tweezers, and a little of kitchen paper. Plus a lot of patience and a steady hand.
Often it's not enough, the shutter has to be partially disassembled, cleaned... and the leaves reseated!
Of all SLR lenses, according to my experience the worst affected are those made in the soviet bloc.
Even CZJ ones, which were the best of the crop. Interestingly, also West Germany lenses of similar vintage can be found with the same problem.
Pentax objectives, at least those i bought, do much better.
Cheers,
and thanks for all your very interesting posts
Paolo