K-series vs M-series image quality-wise?

pathdoc · 10-27-2016, 07:47 AM

Originally posted by pinholecam

The M20/4 is so small and hence easily added to the bag when going out ('just in case') - so is that considered 'better'?

In practical, day to day terms - yes. Results look impressive too.

lytrytyr · 10-27-2016, 06:56 PM - **1 Like**

Originally posted by Piotrek K

I'm wondering if the K-series ones are really better in IQ compared to the M-versions?

Well, you need to remember that the K lenses do not form a coherent series, the way the M lenses do.

Early K lenses were just M42 lenses remounted for the bayonet.
Then later, for example, the K 24/2.8 was introduced and marketed together with the M lenses,
and its only distinction from the majority of the M series was its 52mm filter ring diameter
(which nevertheless is shared with the M 200/4).

This is Pentax we are talking about, after all,
where the K3 replaced the K5 while the K50 replaced the K30,
so it isn't all going to be completely logical!

glasbak · 10-30-2016, 04:06 AM

My statement is that there are very few M lenses superior to the K lens they replaced, although the center performance is generally good, the more compact optical constructions probably did have a negative effect on the edge and corner performance (which you won't notice much on APS-C).

lytrytyr · 10-30-2016, 07:52 AM

Originally posted by glasbak

My statement is that there are very few M lenses superior to the K lens they replaced

The best lens is the lens you have with you!

While the tiny little M 20/4 has its optical faults (softness, mustache distortion),
a lot of users prefer it to the K 20/4 because it's just so easy to bring along.
And then they're blown away by the beautiful color rendering.

TaoMaas · 10-30-2016, 08:48 AM

I've never really noticed a significant difference in performance between my K-series lenses and my M-series ones. For the most part, as it applies to lenses, anything Pentax puts their name on is of decent quality. I think we worry about this stuff FAR too much.

GeneV · 10-31-2016, 06:22 AM

Originally posted by TaoMaas

I've never really noticed a significant difference in performance between my K-series lenses and my M-series ones. For the most part, as it applies to lenses, anything Pentax puts their name on is of decent quality. I think we worry about this stuff FAR too much.

Agree that we worry about this stuff far too much.

I have my favorites in all of the manual focus series. The SMC K 135/2.5 has remained one of my favorites for close to 40 years, getting another revival with the K1. The M 20mm/4 is another fave, for the reasons mentioned by several here. I'm also partial to my copy of the M50/1.4. One can't really generalize.

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10-27-2016, 07:47 AM	#16
pathdoc Pentaxian Join Date: Mar 2015 Photos: Gallery \| Albums Posts: 6,381	Originally posted by pinholecam The M20/4 is so small and hence easily added to the bag when going out ('just in case') - so is that considered 'better'? In practical, day to day terms - yes. Results look impressive too.

10-27-2016, 06:56 PM - 1 Like	#17
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by Piotrek K I'm wondering if the K-series ones are really better in IQ compared to the M-versions? Well, you need to remember that the K lenses do not form a coherent series, the way the M lenses do. Early K lenses were just M42 lenses remounted for the bayonet. Then later, for example, the K 24/2.8 was introduced and marketed together with the M lenses, and its only distinction from the majority of the M series was its 52mm filter ring diameter (which nevertheless is shared with the M 200/4). This is Pentax we are talking about, after all, where the K3 replaced the K5 while the K50 replaced the K30, so it isn't all going to be completely logical!

10-30-2016, 04:06 AM	#18
glasbak Veteran Member Join Date: Apr 2009 Location: Netherlands Posts: 369	My statement is that there are very few M lenses superior to the K lens they replaced, although the center performance is generally good, the more compact optical constructions probably did have a negative effect on the edge and corner performance (which you won't notice much on APS-C).

10-30-2016, 07:52 AM	#19
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by glasbak My statement is that there are very few M lenses superior to the K lens they replaced The best lens is the lens you have with you! While the tiny little M 20/4 has its optical faults (softness, mustache distortion), a lot of users prefer it to the K 20/4 because it's just so easy to bring along. And then they're blown away by the beautiful color rendering.

10-30-2016, 08:48 AM	#20
TaoMaas Pentaxian Join Date: May 2007 Location: Oklahoma City Photos: Gallery \| Albums Posts: 3,574	I've never really noticed a significant difference in performance between my K-series lenses and my M-series ones. For the most part, as it applies to lenses, anything Pentax puts their name on is of decent quality. I think we worry about this stuff FAR too much.

10-31-2016, 06:22 AM	#21
GeneV Veteran Member Join Date: Oct 2008 Location: Albuquerque NM Photos: Albums Posts: 9,830	Originally posted by TaoMaas I've never really noticed a significant difference in performance between my K-series lenses and my M-series ones. For the most part, as it applies to lenses, anything Pentax puts their name on is of decent quality. I think we worry about this stuff FAR too much. Agree that we worry about this stuff far too much. I have my favorites in all of the manual focus series. The SMC K 135/2.5 has remained one of my favorites for close to 40 years, getting another revival with the K1. The M 20mm/4 is another fave, for the reasons mentioned by several here. I'm also partial to my copy of the M50/1.4. One can't really generalize.