Pentax K - Pentax M

[jclaude]

Hello, lensadic's

Can some of you clarify the differences between Pentax lenses K and M?
I don't see too much, but as I don't have the 'same' lens in the two version it is difficult to compare.
I own a 28mm3.5 in M and 50mm 1.7and 1.4 in K. They have the same mount, look of the same construction...
I'm simply curious.

Thanks

Jean Claude

[Rolf]

Did you have a look here

http://www.pentaxforums.com/lensreviews/

[Spotmatic]

The K series is the original series lenses with a a K-mount, called "SMC PENTAX" in boldface. Often with the same glass as the last series of the M42 Super-Multi-Coated Takumars. The M-series had new (smaller) lens designs and had a "-M" in the lens name.

The 50mm F/1.7 does not exist as a K lens, it's a M lens. Or did you try to type 50mm F/1.8 which indeed is a K series lens?

In my opinion the K series is slightly better built than the M series.

[DanielT74]

K series had some real stand-outs, like the Zeiss designed 15/3.5 and 28/2. Besides the 135/2.5 is ever popular, the 30/2.8 is a very sharp lens and the 50/1.2 is excellent. Also 85/1.8 and 200/2.5 are very very good.

M series is not as good, though reasonable. The 50/1.4 is optically the same as the K version I believe and is a fine lens. There is the M*300/4 which is a nice telephoto. And that's all I recall - no experience with M* lenses, just hearsay information.

[hoanpham]

M* 300mm f4 is an excellent performer.
A little bit soft wide open, just a little bit, one click down it is razor sharp.

It is optically identical to the newer A* 300mm f4.

[jclaude]

Thanks for your replies.
You are right Spotmatic the 50/1.7 is an A, not a K, I bought it with my Super A.
I also have a 135/3.5,K which is not bad at all.
I am quite surprise that they produced a M serie after the k, with lower performances!

Jean Claude

[Spotmatic]

Well, they had to design smaller lenses to go with their smaller cameras (ME, MX etc.) so I can understand that. From a collector and user point of view I would recommend the K series however.

[semso]

Spotmatic wrote:

Or did you try to type 50mm F/1.8 which indeed is a K series lens?


I never saw one Pentax or Takumar 50mm F/1.8 ?!?


semso

[Spotmatic]

[tromboads]

People often say the "M" series are lower quality (I'm nearly convinced it simply has to be an arrangement of marketing) but I've never been able to tell the difference when using.

I own a bunch of different Takumers through K and M branded glass. And to be honest. The M's are smaller, lighter, still naturally multi-coated, cheaper, still all metal.

I really struggle to force myself to take say the k55 f1.8 or the Tak 50 f1.4 (which are both magical, and will cure your family of cancer whilst making you dead set attractive to the opposite sex) over a lonely little 50mm M series f2 There just isn't enough of a difference in quality anywhere to justify it. Well to fap on about using it that is.

If I knew what I knew now, I would go back in time, and stop myself from bidding on all those ebay items :p I would have my 50mm f2 M series and be a happy little Vegemite (pentax k10d user here)

K's are fun because they were the last of the Takumers. If you have the space and cash to collect them and put them up on your wall, by all means don't let me talk you out of it, because they are beautiful as artifacts, plenty perfect to continually use, and the smell. :S They smell amazing

[TimHar]

Hello,

This is my first post

Regarding the difference between M and K, I had M 28mm f3.5 and I have K 28mm f3.5, K is sharper, crispier and has better rendition.
Thou M 28mm f3.5 is a good lens. Build quality is the same, M's are smaller and it's said that M means mini.

Most accurate info you'll find at http://kmp.bdimitrov.de/lenses/index.html

[aoleg]

[iangreenhalgh1]

I have M 2/50 and M 1.7/50. Both are excellent imho. The 2/50 is just as sharp I think, and on my NEX-3 it produced excellent results even wide open.

[Spotmatic]

Regarding the difference between the K and M series: if you disassemble them then you'll see that the M series uses more aluminium, even for the helicoids. The K series uses brass for that, so purely on build quality alone the K series will always win.

[peterqd]

[TimHar]

[womble]

The whole thing is made even more complicated by the fact that some K series lenses continued to be made throughout the M series period, for example the K50/1.2 and the K15/3.5, although they use the smc font rather than SMC. Having quite a few K and M series lenses I would say that on the whole the K series lenses are optically better than the equivalent M series ones, but there are exceptions (at least with my copies of the lenses which is, of course, not very scientific). For example, I find my M200/4 somewhat better than my S-M-C Tak or K series 200/4. I would guess the K200/2.5 should out perform all those lenses but I don't have one of those to try! I did an informal comparison between my M28/3.5 and my K28/3.5 and the K does just win, but only with direct comparison and pixel peeping. If I only had the M I'd be very happy with it indeed.

As to build quality, the M85/2 I have is so silky smooth I cannot really imagine how that aspect of the lens could be improved. I do find the A series lenses built to a lower standard, for example in the use of plastic aperture rings. I don't have any A* lenses though.

As it is, I find myself using a mixture of lenses (Taks, Ks, Ms, the odd A and some DAs) and generally being very happy with them. I would like to get a really good quality longer lens (e.g., the A* 300/2. as the Tammy I have sucks, but that'll have to wait until I win the lottery or something.

Cheers Kris.

NB. Based on owning (primes):
S-M-C/SMC Takumar 28/3.5, 50/1.4, 55/1.8, 135/3.5, 135/2.5 (ver 1), 150/4, 200/4
K15/3.5, 17/4, 24/2.8, 28/3.5, 35/3.5, 50/1.2, 55/1.8, 135/3.5, 135/2.5, 200/4, 300/4
M20/4, 28/3.5, 50/1.7, 50/2, 85/2, 100/2.8, 200/4
A28/2.8, 50/1.4, 50/1.7

[Tesselator]

Taking it in a slightly different direction; M-42 is a threaded mount (screw mount). K is a bayonet mount.

Many or perhaps almost all M mount Pentax lenses have a metal focus ring and an all metal body. Focus operation across almost all M models is buttery smooth - akin to $2k and $4k Leica lenses or even better. They feel very high quality in the hand and mounted on the camera.

Most or all K mount Pentax lenses use a rubber focus ring. The aperture ring is always stiff and unsmooth unless it's nearly worn out. Focusing operation is not very smooth - nothing at all like the M mount lenses. Pretty much the same as MF Nikkors, non-L canon FD, or Oly lenses. Actually Oly is often a little smoother. They don't feel all that high quality in hand nor on camera - but pretty average.

In terms of IQ most M mount pentax lenses have a very creamy and "painterly" bokeh. There are five general kinds of M mount pentax Takumars: Takumar, Auto-Takumar, Super Takumar, SuperMultiCoated Takumar, and SMC Takumars. Almost without exception the coatings are:

Takumar - Single Coated
Auto-Takumar - Single coated
Super Takumar - 3 coating layers
SuperMultiCoated Takumar - 7 coating layers
SMC Takumars - 7 coating layers.

I think it's 7 anyway but it's been awhile since I read it so it might be 6 or 8 - but I think I'm remembering right that it's 7.

Many, perhaps most Auto-Takumars and Takumars have a noticeable amount of color fringing (LoCA, etc.) tho usually not too much purple fringing (PF) around high contrast edges. IMO the way it's rendered in the image it actually adds to the character of the lens - most are still very sharp and the OOF color gradient fringes make them all the more painterly. Flares are very defined and pronounced - which can be a very nice effect!

Super Takumars are about the same thing but less (almost no) PF and flares are less defined and pronounced.

SuperMultiCoated Takumar are about the same again but much less LoCA and flares are dead and dull like most other multi-coated lenses. Lens reflections are about all that's left for using flares creatively.

SMC Takumars begin to use rubber focus rings and inferior dampening grease - very near to K mount pentax models. IQ is very slightly different than SuperMultiCoated Takumars.

With K-mount lenses they started dropping the Takumar insignia. "Takumar" was the name of Asahi's Founder's brother: Takuma Kajiwara. He was a little famous for his oil and acrylic portraits (paintings). And since the early Takumars uniquely rendered a "painterly" bokeh the name seemed to apply very well. By the time SMC and K-Mount lenses were being made this painterly rendering was gone and so it seems fitting that the painter's name was dropped as well. Later in some Ka-mount lenses the Takumar name was used again as the lenses they applied the name to were designed to recapture that painterly look. Whether they actually do recapture that look or not you'll have to buy one and find our for yourself.

If I wanna be creative Takumar and Super-Takumar are preferred. Very much preferred! They look pretty awesome mounted on the camera too! If I want good, standard or typical looking, vanilla photographs then I use one of my SMC Takumars or one of my SMC Pentax K-mount lenses. I have a few Ka-mount Takumars too but haven't used them enough to really comment intelligently.

If you wanna know about the various series of lenses they made from about 1975 or 1980 (after K) then wiki is a good source: http://en.wikipedia.org/wiki/Pentax_cameras#K_Series IMHO, there's nothing significant between them - various qualities and many attempts at AF and then on to Digital. Not of much interest for me. I like MF lenses.



.

[womble]

[tromboads]

And again, we are splitting hair's here, not to mention that lube dries out over time, not to mention how little or how much either example of lens has been used.

So in summary,

Don't worry, And just take pictures god darn it.

[Tesselator]

Hehehe, I have to agree with that!

Even if only cuz the Fonz approved it!

[womble]

Seems like the best plan. I had a lovely walk yesterday swapping MF lenses between my Pentax LX and my K20D. And I've just had the quote back for turning my bargain bin SV back into a working piece of beauty. So all's well with the world.

K.

[tromboads]

old cameras are the fun cameras. *nods*

[peterqd]

[womble]

I bought the SV for £3 as it wasn't working hoping that it would just need a CLA. I sent it to Eric Hendrickson and he has quoted me $92 to restore it and post it back to me. Seems like a good deal for a classic camera. I only have one Auto Takumar to go with it though...

I'm looking forward to having a play with this one as some of the guys on pentaxforums rave about it being the best of the Pentax M42 cameras. I doubt I can be entirely tempted away from my lovely ES/ESII but it will be nice to play with.

Cheers, Kris.