Review: Pentax K SMC 28mm 1:3.5

Pentax SMC 3.5/28 K front

The Pentax is a rather small and affordable 28mm lens and  Pentax had a reputation for their very effective coatings. Read on if you want to know why I like it so much on my 24MP fullframe Sony a7.


  • Diameter: 63mm
  • Length: 47mm
  • Weight: 261g
  • Filter Diameter: 52mm
  • Number of aperture blades: 5
  • Close Focusing Distance: 0.3m
  • Mount: Pentax K

The Pentax K SMC 1:3.5/28 usually sells for around $45-90 at (affiliate link). 
In Germany you can buy it for 40-85€ at (affiliate link). 

Sample images

Sony a7 | Pentax SMC K 1:3.5/28 | f/11 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/11 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/11 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/11 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/3.5 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/3.5 | full resolution


The Version I review is the K version. There is also a M version which is smaller but, from the reports I have read, not on the same levels optically.Pentax SMC 3.5/28 K on Sony a7



You can find the full resolution test images in the Pentax SMC 3.5/28 flickr album.


f/3.5: Good sharpness across the frame with moderate contrast. The corners are a bit softer and somewhat hazy.

f/5.6: Excellent to very good in the center and midframe region with very good contrast. The corners are still a bit hazy.

f/8: Very good sharpness across the frame.

f/11: A little softer in the center due to diffraction.


The Pentax 3.5/28 is my favorite wideangle lens at the moment.

The lens is very well built with very low tolerances and an all metal housing. It is also quite small so handling is very pleasant. Only the reversed travel direction of the focusing ring is a bit bothersome for me who is used to Minolta SR/Canon FD/ Zeiss C/Y lenses.

Pentax SMC 3.5/28 K Product image

Optically it leaves little to be desired. At shorter distances you get decent bokeh and good sharpness from f/3.5.

Sony a7 | Pentax SMC K 1:3.5/28 | f/8 | full resolutionSony a7 | Pentax SMC K 1:3.5/28 | f/8 | full resolution

Sony a7 | Pentax SMC K 1:3.5/28 | f/8 | full resolutionSony a7 | Pentax SMC K 1:3.5/28 | f/8 | full resolution

Stopped down to f/8 it is very sharp across the frame. There is some field curvature but of the good kind where the corners are focused in front of the center. CA correction is exceptional (better than the Zeiss Distagon 2.8/28).

Sony a7 | Pentax SMC K 1:3.5/28 | f/8 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/8 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/8 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/8 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/8 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/8 | full resolution

What surprised me the most was the truly exceptional flare resistances and very high contrast. I didn’t know that a 40 years old lens could be that flare resistant. The Pentax is even better than the Zeiss Distagon 2.8/28 in this regard.

Sony a7 | Pentax SMC K 1:3.5/28 | f/8 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/8 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/8 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/8 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/8 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/8

The Pentax K 3.5/28 has only 5 aperture blades which result in reasonably well defined sunstars.

Sony a7 | Pentax SMC K 1:3.5/28 | f/11 | full resolution
Sony a7 | Pentax SMC K 1:3.5/28 | f/11 | full resolution


Pentax SMC 3.5/28 K on Sony a7

The Pentax SMC K 3.5/28 doesn’t have any real weakness. It delivers surprisingly good performance in a small package.

If you consider the very good performance the lens offers a great value. That is if you can find one, it was sold for only a short period of time so it is quite rare and it’s successor the Pentax SMC M 3.5/28 isn’t as good.

The Pentax K SMC 1:3.5/28 usually sells for around $45-90 at (affiliate link). 
In Germany you can buy it for 40-85€ at (affiliate link). 

If this review was helpful to you, please consider using one of my affiliate links. I will earn a small commission on your purchase and it won’t cost you anything. Thanks!

Further Reading

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I have two hobbies: Photography and photographic gear. Both are related only to a small degree.

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74 thoughts on “Review: Pentax K SMC 28mm 1:3.5”

    1. thanks Phillip, I’ve got one in K mount in pretty mint condition. bought it for $90 . Fully agree it is extremely flare resistant, even I challenged it against direct sunlight or sideways without lens hood . It has no CA at all !!.. Considering the age it exceeds my expectations. Only has slight curvature on the edges. The cons it is only f3.5 that requires me to zoom with my A7ii to finely focus on objects. Would have been faster if it was f2 or f2.8. Sample shots on my instagram, search for my name.

    2. Just recently picked up the SMC K 28mm F2 Distagon Clone, But after seeing this I still want a copy of this 3.5 lens, and I found someone selling a mint copy I think i can snag for sub 100 dollars. I’m happy 🙂

  1. Anybody knows the difference to the Asahi Pentax Takumar 28mm 3.5? And any opinions about the Olympus Zuiko 28mm f/3.5?

    1. No personal experience but anything I have read about the Takumar was less than enthusiastic.

      The Oly 3.5/28 is actually a tad sharper in the corners but it flares easily and the Pentax is noticeably more contrasty.

    2. Soso, the Takumar is different optically (as is the Pentax M as Phillip noted.) I have not tried it but everything I have read supports that the original K mount version in this review is the one to get.

      The Olympus 28mm f/3.5 is very good, but is only single coated. It has lower contrast, is less resistant to flare, and even though the corners are very good….my copy suffers from a midzone dip.

      The Pentax that Phillip reviewed is my favorite 28 as well, after trying many.

      Great review Phillip!


    3. It’s useful to know that “Takumar” was what Pentax called its lenses for 35mm SLRs (rather like Minolta called its lenses “Rokkor” and Oly used “Zuiko”) in the M42 screw mount era. With the introduction of the K bayonet mount, however, they dropped the Takumar name for 35mm format lenses and simply called them SMC Pentax. The reason this is important is that later, Pentax recyled the Takumar name for a small range of budget lenses for 35mm SLRs, which lacked the SMC coating and were usually of simpler optical designs.

      So, the key rule of thumb is: M42 screwmount lenses labelled Takumar – especially “Super-Multi-Coated Takumar” and, later, “SMC Takumar” include some wonderful lenses; K bayonet lenses for 35mm SLRs labelled “Takumar” or “Takumar-A” are pretty much to be avoided. (The good K-mount manual lenses are amongst those labelled mostly “SMC Pentax”, “SMC Pentax-M”, or “SMC Pentax-A”.)

      It gets even more complex if you include lenses for the 6×7, where Pentax carried on using the Takumar name for the top end glass…

    4. Both the Tak version and the later M version have different optics. This really is the best version I’ve seen.

  2. I was initially put off by it being a slow lens–but it’s a real performer with great sharpness and colors on my a7. I concur about the great flare resistance. The colors are just wonderful. Outperforms my Contax G 28mm f2.8 on my a7 which has the dreaded magenta cast.

  3. Awesome photos, Phillip! I mean all of your pics across the whole site – really like your work and style. I stuck with Pentax for decades because I loved their lenses, especially the 6×7 stuff. However, have recently moved to A7ii because the Sony E mount is so versatile, and I also gave up waiting for a Pentax full frame. I have never shot the K 3.5/28 but it does not surprise me that you have found an excellent performer. I very rarely shoot wide angle these days but if and when I do I rely on a Distagon 2.8/28. If I want to capture sonething really wide then I default to my handy Pentax Q with its native 3.8-5.9mm wide angle zoom (21-32 equiv or 17-27 on the later body), which is a surprisingly excellent EDIF optic in a toy-like package!

  4. Hat jemand eine Idee wo ich diese Objektiv zu einem Normalen Preis in Deutschland bekomme auf E-Bay gibt es nur das M in ganz Europa? irgendwo muss man es doch bekommen?

    1. Du kannst dich in Online-Kleinanzeigen auf die Suche machen, ich habe z.B. gerade eins auf aufgeschnappt (60€ inkl. Versand).

  5. Man muss einfach Geduld haben ! A very good lens indeed. The AWB of the A7 is lost with this lens so you have always some work in PP .
    From Pentax :
    I am using also the M50 1.4 . It is good from f2 and has a really beautiful bokeh . Everybody should have a SMC Takumar 55 1.8/2 , cheap, sharp stopped down and a lens with character at wide apertures ( soft bokeh, unique rendering).

  6. I’ve got a mint Sony a7r on the way from eBay! I’m digging around for one of these Pentax 28mm lenses but sellers on the Bay are jacking the prices up on this model. I will find one and utilize it!

  7. These Pentax 28/3.5 lenses are really hard to find! I have one that I use on my A7r. It’s a nice lens for landscape photography, but I’m not as enthusiastic as Phillip. This lens really wants to be at f/11. I find the corners and edges are really bad at f/3.5 and even f/5.6. At f/8 corners are so-so. By f/11 it’s at its best for me (balancing a bit of diffraction versus over all sharpness). It’s still great value if you can find one at a good price, but beware the larger apertures.

    One word of caution: all the Pentax K to Sony E adapters I’ve been able to find position the lens off-centre compared to most other lenses (in other words, the aperture and distance scale are rotated away from “up top”; this is because of the “fin” on the K mount. (Stop reading now if you don’t like lens mutilation… I had to snip the fin to make it work on my Tilt-Shift adapter because it got in the way!)

    I’ve also owned and tested (and then sold) the Super-Multi-Coated Takumar 24/3.5 and 28/3.5 The 28/3.5 is mechanically the most beautiful lens I’ve every owned — so smooth and solid and pleasant to use… I used to enjoy just holding the darned thing and operating the rings. Unfortunately, both the Takumar 24 and 28 are terrible on the A7r and A7 — as in completely unusable. They never got decent. In contrast, the Super-Multi-Coated Takumar 35/3.5 is remarkably good, and my Super-Multi-Coated Takumar 55/1.8 is astonishing for an old lens (and even compared to much newer ones). If you’re interested in Pentax and Takumar, there are reliable reviews on the Pentax Forum.

    1. Oops… I shouldn’t comment at the end of the day! As Phillip’s picture shows, the Pentax K to Sony E (NEX) adapters don’t position the numbers off-centre. It’s the Pentax K to Canon EOS adapter that does that (because of the design of the Canon internals). This is a problem for me only because all my Takumar and Pentax lenses are adapted to mount on Canon EOS, which is the mount used by my Mirex Tilt-Shift adapter (Canon EOS to Sony E).

  8. Probably the A7r is a difficilt camera in the corners. The performance of my K28 3.5 is good from f5,6 on my A7.

    1. I can confirm that smc pentax k 28mm f3.5 needs f11 to bee sharp in corners with Sony A7rii.But I must say this lens is very well corrected and it doesnt have the usual ca and vinjetting as other legacy lenses. I read someone said “its like the lens has a built in polariser”, and Think I see that in my pictures, much better skies and the picture is very clear and sharp.

  9. Wondering how it compares to the Sony FE 28mm f/2? I currently have the Sony FE, wondering if it is worthwhile to pick this up. Manual focus not a problem, though f/3.5 is my drawback.


  10. I did a little comparison of my 28mm lenses (Pentax K28/3.5, Canon nFD 28/2, Minolta MC 28/2.5):

    Results are as expected (and in line with yours), the K28/3.5 wins handily on all counts except max. aperture. The MC28/2.5 is sharp in the center from f/2.5 but the corners are fairly weak, stopping down improves them but they never catch up with the other two. The nFD is a good overall performer, center sharpness is decent wide open and on par with the MC28/2.5 stopped down. The corners are usable wide open and sharpen up quickly (a lot better than the Minolta, not quite as good as the Pentax). Contrast is fairly low at large apertures and remain rather low in the corners.

    I’m not sure if the field of view really suits me but I suspect I’ll end up like you: K28/3.5 + FE28/2

  11. Between this lens and the Pentax SMC 28mm F/2.8 Lens which one would you recommend? I’m trying to know more about these awesome vintage lenses to go with my sony a7r 🙂
    Thank you and love your blog!

      1. There are two versions of the 2.8 😉 the first one is smaller and it was worse. The second one is with the optics from A 28 2.8 and it is better. Pretty comparable to the 3.5 in terms of sharpness.

  12. do you know which one would perform better for night photography ( some night skies etc) , canon FD 24/2.8 or Pentax K 28/3.5.

    Also which one has better sun stars ?

  13. May I ask how did you keep the exif information with this lens? I found I will lose them with my cheap adapter.

  14. I’ve just bought this lens, a friend knew I was looking for one and found it in a shop. So far I am very impressed with it. I also really like the smc-A 50mm f1.4 and smc-A 35mm f2.8; both are significantlysharper than the the Minolta MD equivalents ( f1.7 in the case of the Minolta 50mm) and have better flare resistance.

    The smc-A 50mm f1.4 is my sharpest legacy prime, with the Auto-Rokkor PF 55mm f1.8 coming a very close second.

  15. hi Phillip

    i have been planning to buy a sony A7, i have studied your reviews on cameras and lenses, your views are professional, unbiased and impressive.

    i have a question on Pentax manual lens which i am very interested to buy. when used on A7, will the lens generate cropped images? since A7 is full frame camera.

    my another question is on sony FE 50 mm F/1.8, which you mentioned that you may not recommend it as a multipurpose lens, just wonder which types of shots it’s best at? portrait or landscape?

    thank you in advance!

    1. Images with the 3.5/28 won’t be cropped on the a7.

      The FE 1.8/50 can do both portrait and landscape well. Some lenses are a bit better but how much that matters depends on your needs.

  16. The exact lens which is referenced here is really tough to find. I have seen some that are M42 mount and labled

    the post that Peter Boorman made early on seems to state that this class of lenses are good

    are these similar in performance?

    1. The M42 mount (SMC) Takumar differs from this lens. The Takumar is not bad, but definitely not a match for the K-mount Takumar.

  17. Hello Phillip, First of all I love your blog and have recently bought a Sony A7. Luckily I found a seller online selling this amazing lens too. Quick question have you a page to direct me to set up this manual lens and settings etc as this is my first manual prime lens just to make life easier.

    Regards Trevor

  18. Hello Philip
    I just received the SMC 35mm 3.5 from ebay.
    As you liked the 28mm 3.5 and the 35mm 3.5 is the other legend on the wide side, may I tempt you to review my lens?
    regards Ole

  19. Hi Phillip
    2 years back you commented as – “The Pentax 3.5/28 is my favorite wideangle lens at the moment.”
    Now that you have tested multiple 28MMs like –
    CZ 28MM 1:2 Biogon, Minolta MD 28MM 1:2, Pentax K SMC 28MM 1:3.5, Voigtlander 28MM 1:2 Ultron, Olympus 28mm 1:28 and may be a few more.. which one is your favorite now?
    In the market for a good ~28mm actually, especially interested in one having great micro-contrast (I can even sacrifice a bit of sharpness in lieu of the pop) . Any suggestion?


  20. I took me almost 6 months to find one but the local Salvation Army thrift shop had a beat-up pentax camera with this lens on it for $40. I’ve only taken a few shots with it so far and while really sharp I’m not sure I like the focusing experience being backwards. It also seems to focus well, you need to open up the lens to f3.5, get the focus right then stop down to your desired aperture. Based on the review, I’m going to use it quite a bit more before passing any further judgement.

  21. Hey Phillip,

    Thanks for the review and pointing me to this wonderful lens. I just got one for my a7s and I’m using a K&F adaptor ( I can see how beautiful it can be, but it’s not very sharp towards infinity at whatever f-stop. I checked and I can close focus to about 7.5″, whereas the specs say it should be about 12″. I’m guessing it’s due to a faulty adaptor. What do think?

    Thanks so much!

      1. Oh…I was measuring from the end of the lens; I’m only off now by an inch or 2cm. Thanks!

        In landscape shot with a town or a mountain range far away, focus peaking didn’t quite get to infinity, but I remember you mentioning in one of your tutorials here that peaking isn’t entirely accurate on A7x.

        Hearing about how sharp this lens was, I assumed it would be so at infinity, but being as my copy is a 12MP A7s, maybe it just doesn’t get super sharp. Otherwise, it’s amazing…

        Thanks so much for the quick response and for this wonderful recommendation Phillip!


  22. JPG shooters be aware that for non-landscape uses this lens has slight but noticeable pincushion distortion.

    For RAW shotters: it seems to correct fairly well with the Pentax 40 f2.8 limited lens profile on Lightroom.

  23. Thank you very much, Phillip (and you other guys)!

    Through your site I got bitten by the vintage bug and discovered SO great lenses.
    After the Minolta 35-70 f3.5, the Minolta 75-150 and the Voigtländer 21mm f3.5 FE, this lens now is the fourth one which really blows me away!

    Not only is it the first vintage lens with <35mm which I tested and which hasn't unsharp, smeary corners on my A7III; the most stunning aspect are the colors! It's the only lens I have which doesn't need any color/contrast/clarity tweaking in Lightroom to look punchy, sharp and contrasty like I want it in a final image! Mind boggling!

    Only thing is that with my K&F Concept adapter, I doubt a bit whether I'm really already at infinity when I turn the focus ring to the hard stop. Seems I have to buy a Novoflex once again…

  24. Thanks to this review I started looking at Pentax glass on ebay and landed on a mint copy of Pentax 30mm F2.8 Just wow! I’ve read so much about “those Pentax colours” on forums and review sites, but now I finally got what the hype is all about.

    I started as a 19mm shooter on APS-C, so I’m really at home with this focal length on full frame.

    Thanks Phillip and everyone that has contributed. This lens will probably be on my camera 90% of the time and I’m sure the 28mm is just as good.

    1. Hi Milen, I also received a mint copy of the Pentax 30mm f/2.8, but I am not that impressed. Yes, the colours are warm and saturated and that’s about it. Optically the lens is mediocre. The extreme corners are really weak, even stopped down.

      1. I don’t really care about sharpness that much, more about colours and character. That being said mine seems to be pin-sharp at f8.

        Yoshihiko Takinami’s tests have the 30mm super sharp at f8.

        Maybe try another copy?

  25. I’ve recently bought both the “K” 28mm 3,5 and the much more readily available and cheaper Pentax-M 28mm 3,5 and did a quick’n’dirty comparison today regarding flare resistance. The K is indeed the better one, you can get it to ghost (tiny blue blob) and at certain angles it’ll flare, but the Pentax-M, while also very flare resistant, will ghost more (still by far not as much as most other legacy lenses though). Still, both lenses are really unimpressed by the sun in a corner or just outside the frame, which is pretty spectacular.

    I didn’t compare sharpness, I was interested in the ability to shoot with the sun in frame. I’ve put samples ins this album:

    1. I liked the M a lot on aps-c but on full frame it’s weaker corners come into play. Now I am doubting between the K-28 3.5 and K 30 2.8 which is more rare and costs more. But if I get the 28 I am probably more likely to also get the 30 at some point than the other way around….

  26. The K version has become too expensive. I am using the M version, and I am quite happy with results so far. Plenty sharp, and good contrast. No flare issues.

  27. Je viens de monter ce Pentax 28 f/3,5 sur un Sony Alpha 7 mark 4 pour des essais de paysage et j’ai vraiment pris une grande claque par rapport au Sony 28 f/2, Nikkor ais 28 2,8, Pentax 28 f/3,5 version 2. Merci encore pour vos avis éclairés.

  28. How would the Minolta MD 28mm f3,5 compare to this lens? From what I read, it is a better performer than Minolta’s f2,8 versions and comparable to the (much more expensive) f2.0 once stopped down.

    1. The Minolta has good sharpness stopped down too (I took one of my favorite photos that I actually printed pretty big and put on a living room wall with it). The Pentax is maybe a bit sharper stopped down if you pixel peep (not relevant for real life applications), but it’s huge advantage is the flare resistance.

      You simply can take pictures with it that are impossible to take with the Minolta unless you are going for huge, blocky and ugly flares and ghosts for the “look”.

  29. Hello Philippe, and thank you for this site which is a gold mine! I think I was lucky, I found an almost new Pentax K 28mm f3.5. And for only 80€. I just need to straighten the edge of the upper thread a little, otherwise no filter. This is a lens with a nice contrast, nice colors and very sharp from f3.5. In any case, much better than my Zuiko 2.8/28 that I bought in Paris in 1983.

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