Sharp lens for K mount

MFstooges · Apr 25, 2020

I'm thinking of getting small SLR and been looking at Pentax. My plan is to put a prime wide angle between 40 -24. I read there are lot of lens brands for Pentax mount. It also seems they are produced by same factory but they differ in quality so it's confusing to me.
Does anybody know what lens for K mount that is comparable in performance with Nikkor AIs 24 & 28?

Chrismat · Apr 25, 2020

I know the Pentax 28mm 3.5 gets very good reviews, although I do not know how it compares with the Nikon. I have one and it is excellent.
https://www.pentaxforums.com/lensreviews/SMC-Pentax-K-28mm-F3.5-Lens.html

Paul Howell · Apr 25, 2020

I think all the Pentax K mount prime will match very well against Nikon ALs. I have a 28 2.8 and recently was given a Pentax 402.8 by a friend, first impression is a nice and sharp lens with good contrast. I shot it on a digital body, rought rest using my lens test chart, easily resolved 200 Lmm, color was faithful, dont know how well that will translate to film.

MFstooges · Apr 25, 2020

Is the 28 f3.5 a better performer than f2.8?
I read some good things about Vivitar 28 f2 but this seems to have generic brands alt i.e. Kiron, Kino etc and people don't really know which one is which

runswithsizzers · Apr 25, 2020

I have been very impressed with a SMC Pentax-M 35 mm, f/2.0 I bought recently. Not only is it sharp, but it focuses closer, and has a wider aperture than many 28-35mm lenses.

Chrismat · Apr 25, 2020

MFstooges said:
Is the 28 f3.5 a better performer than f2.8?
I read some good things about Vivitar 28 f2 but this seems to have generic brands alt i.e. Kiron, Kino etc and people don't really know which one is which

I've read reviews that have noted the 3.5 is better than the 2.8, although I've never had the 2.8 to compare it.

John Bragg · Apr 25, 2020

MFstooges said:
Is the 28 f3.5 a better performer than f2.8?
I read some good things about Vivitar 28 f2 but this seems to have generic brands alt i.e. Kiron, Kino etc and people don't really know which one is which

Here is some info on Vivitar Komine lenses.
https://www.pentaxforums.com/userreviews/vivitar-28mm-f2-0-mc-close-focus-wide-angle-series.html
Serial number indicates maker. Eg starting 28 = Komine.

removed account4 · Apr 25, 2020

which Pentax are you gunning for ? I have a me super. its small and pretty much PERFECT. any lens made by Pentax ( asahi ) is a keeper, I don't have any off brand Pentax lenses, and they are sharp as nails, opened up they have a nice OOF thing going on.
have fun MFstooges, there are some great deals out there so it won't break the. bank..
John

NortheastPhotographic · Apr 25, 2020

The FA Limiteds seem like a great choice here. 43mm or 31mm.

Paul Howell · Apr 25, 2020

In the day Pop Photo tested the FA 43mm Limited and Konica 40mm, found both be as sharp as Leica or Zeiss, or sharper. I assume Pop photo tested with microfilm and bothe exceeded the resolution of Tmax 100. I shoot on a K 1000, so a standard K works fine for me, but if you want a M body you might to get a KA version.

NortheastPhotographic · Apr 25, 2020

Paul Howell said:
In the day Pop Photo tested the FA 43mm Limited and Konica 40mm, found both be as sharp as Leica or Zeiss, or sharper. I assume Pop photo tested with microfilm and bothe exceeded the resolution of Tmax 100. I shoot on a K 1000, so a standard K works fine for me, but if you want a M body you might to get a KA version.

Possibly true stopped down. It's fairly tough to nail focus at 1.9 and you definitely lose some snap. I do use this lens more than any other of the FA Limiteds. I have all 3!

Les Sarile · Apr 26, 2020

MFstooges said:
I'm thinking of getting small SLR and been looking at Pentax. My plan is to put a prime wide angle between 40 -24. I read there are lot of lens brands for Pentax mount. It also seems they are produced by same factory but they differ in quality so it's confusing to me.
Does anybody know what lens for K mount that is comparable in performance with Nikkor AIs 24 & 28?

The Pentax MX is the smallest SLR with the largest viewfinder magnification. Coupled with the exceptional Pentax 40mm f2.8 pancake lens makes for an exceptionally compact combination.

Pioneer · Apr 26, 2020

The nice thing with the K-mount Pentax cameras is that you can also enjoy a huge selection of M42 lenses from the past.

As much as I love and use Pentax glass I have to say that I think my Voigtlander Ultron 40/2 SLII is probably one of the sharpest prime lenses that I own irregardless of brand. The fact that it is an f2 lens means that it isn't all that difficult to get critical focus wide open. Finally it is pretty compact so it is a good match to the MX or the LX.

Les Sarile · Apr 26, 2020

MFstooges said:
Sharp lens for K mount
Does anybody know what lens for K mount that is comparable in performance with Nikkor AIs 24 & 28?

Just to give you a reference, below I tested the Pentax Macro 50mm f4 on my Pentax body using Kodak Techpan @ ISO25, ideal shooting condition and setup with a 12233 resolution test chart to provide the detail need to evaluate the overall resolving power of this system.

Full res version -> http://www.fototime.com/8372250EA44CB06/orig.jpg

I did this test on my lenses as I wasn't sure just how good - or bad, they are given that they were not factory new. As you can see from the results above, not even a 36MP Nikon D800 can resolve all the detail this lens can resolve. As a result of this test, I can't determine what is the limiting factor - is it the lens or the film or some other?

I've tested all my Pentax prime lenses - bought used, and they will not be the limiting factor in achieving all the detail that the scene has.

Billy Axeman · Apr 27, 2020

Les Sarile said:
The Pentax MX is the smallest SLR with the largest viewfinder magnification. Coupled with the exceptional Pentax 40mm f2.8 pancake lens makes for an exceptionally compact combination.

That is a great combination, the MX with the Pentax-M 40/2.8.

What many people 'forget' though is to use a hood on this lens, which is necessary for maximum sharpness. It is a common mistake people make with pancake lenses, because they want to keep them small. This lens has a relatively low number of elements (5 elements in 4 groups) which is a recipe for good contrast, perceived as sharpness. However, a hood is needed to avoid flare and keep contrast up. The original hood is the RH-R49 but I use the MH-RA 49 from the FA 43, a well made metal screw-in hood which looks fabulous on this lens, and you can get it new.

The 40/2.8 is a very affordable lens but it is surprisingly sharp. It also combines very well with the Pentax ME (Super), which is just as small but with another form factor.

benjiboy · Apr 27, 2020

I don't like pancake lenses, they are difficult to manipulate and generally don't give as good photo-technical quality as full-size lenses.

NortheastPhotographic · Apr 27, 2020

benjiboy said:
I don't like pancake lenses, they are difficult to manipulate and generally don't give as good photo-technical quality as full-size lenses.

Depends on the Pancake lens. The aforementioned Voigtlander 40/2 is not only a pancake, but also a fabulous performer. As is the 43/1.9 FA Limited. The 40/2 is probably better than the Penatax Limited, but I like the FA because it AFs on my MZS and focuses just as smoothly on the LX. I wouldn't write them all off.

Billy Axeman · Apr 27, 2020

benjiboy said:
I don't like pancake lenses, they are difficult to manipulate and generally don't give as good photo-technical quality as full-size lenses.

Imagine a Nikkor 45/2.8 P on an F5

MattKing · Apr 27, 2020

benjiboy said:
I don't like pancake lenses, they are difficult to manipulate and generally don't give as good photo-technical quality as full-size lenses.

A pancake lens with an FD mount would probably require compromises, due to the size of the mount.
A pancake lens with a K mount or OM mount would be much more likely to be compromise free.
I've always wanted a Zuiko 40mm f/2, but the price has always been higher than what would make sense for me.
But I still would like one

Ian Grant · Apr 27, 2020

I have the Pentax 28mm f2.8 M and it's a superb lens. I also have a Tamron 28mm f2.5 Adaptall 2 lens and that's equally as good. I have a few Adaptall lenses because I can use them on my Spotmatics and SV as well, I have the full aperture M42 ES/F adapters.

Ian

Hatchetman · Apr 27, 2020

the 28mm f3.5 is a really good lens and pretty cheap. better than the 35mm f2.0 IMO.

warden · Apr 27, 2020

Les Sarile said:
The Pentax MX is the smallest SLR with the largest viewfinder magnification. Coupled with the exceptional Pentax 40mm f2.8 pancake lens makes for an exceptionally compact combination.

That's a tidy package! Very nice.

PGillin · Apr 27, 2020

Any Pentax SMC prime is going to be quite good. In all likelihood better than the off-brand lenses, but of course there are some exceptions there.
All the K mount lenses are DECIDEDLY NOT made in the same factory. Pentax had it's own production, as did Ricoh, and several of the big 3rd party lens manufacturers made lenses for K-mount under their own names and relabeled. Ricoh lenses are generally quite good, though there is a little more variation than in the Pentax 1st party line up, and they made more consumer-focused glass, with fewer exotics like tilt-shifts, macros, and super-teles.
The Adaptall SP lenses, of course, come in K-mount and are good lenses relative to their contemporaries, but I don't believe the made much in the 28-50mm range, not wanting to compete with inexpensive and excellent first-party 35mm and 50mm kit glass.
Stay away from the K-mount Takumars, which are unrelated to the very good M42 Takumars.
The limited lenses are known to be very good, though I haven't shot with them so other posters on this thread are better informed in that area.
You would do well to look at the lens review database on pentaxforums, and perhaps join up over there. There are some very knowledgeable posters and a good, largely pentax-specific classifieds section. (Hopefully I'm not transgressing too much by plugging another forum here. I have been on there for years, since my days shooting Pentax, and still check in occasionally.)

Having used Nikon and Pentax, I would expect lenses of the same era, focal length, and aperture to have a fairly similar performance. I've also never been blown away by Nikon's wide primes. I use my Nikkor 28/2 much less than my 20-35/2.8, and would not be at all upset if an SMC-A 28/2 in F-mount miraculously appeared in my bag. YMMV.

Please feel free to send me a PM or reply here if there are any specific questions I may be able to help you with.

jim10219 · Apr 27, 2020

Chrismat said:
I've read reviews that have noted the 3.5 is better than the 2.8, although I've never had the 2.8 to compare it.

From what I've read, the 3.5 is better wide open, and the 2.8 better stopped down. I have a 2.8, and never used a 3.5, so I can't verify. But I will say that the 2.8 isn't super sharp wide open, but it's also not too bad. Definitely usable.

Hard to go wrong with any of the old Pentax primes. I've got a decent collection of them and can't say that I've ever come across one that disappointed me. Maybe it's luck.

Les Sarile · Apr 27, 2020

jawarden said:
That's a tidy package! Very nice.

Size reference . . .

Sharp lens for K mount

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