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SMC Pentax-M 28mm F3.5 Review RSS Feed

SMC Pentax-M 28mm F3.5

Reviews Views Date of last review
53 234,481 Tue April 19, 2022
Recommended By Average Price Average User Rating
100% of reviewers $59.69 8.86
SMC Pentax-M 28mm F3.5

SMC Pentax-M 28mm F3.5
SMC Pentax-M 28mm F3.5

The slower of the two M variants, it succeeded the original K 28mm lens.

SMC Pentax-M 28mm F3.5
©, sharable with attribution
Image Format
Full-frame / 35mm film
Lens Mount
Pentax K
Aperture Ring
Yes (no A setting)
Automatic, 5 blades
6 elements, 6 groups
Mount Variant
Check camera compatibility
Max. Aperture
Min. Aperture
Min. Focus
30 cm
Max. Magnification
Filter Size
49 mm
Internal Focus
Field of View (Diag. / Horiz.)

APS-C: 55 ° / 46 °
Full frame: 75 ° / 65 °
PH-S49 (28/35mm)
Dedicated hard case
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Diam x Length
63 x 31.5 mm
180 g
Production Years
1977 to 1985
Engraved Name
smc PENTAX-M 1:3.5 28mm
Product Code
User reviews
Manual FocusAperture RingFull-Frame SupportDiscontinued
Price History:

Add Review of SMC Pentax-M 28mm F3.5
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New Member

Registered: July, 2017
Location: Tbilisi
Posts: 18

2 users found this helpful
Review Date: August 29, 2017 Recommended | Price: $40.00 | Rating: 9 

Pros: So many. See the review
Cons: M mount - M42 lenses are easier to use, not the best sharpness out there
Sharpness: 8    Aberrations: 9    Bokeh: 6    Handling: 10    Value: 9    Camera Used: K-50   

After I switched from Nikon, my lifelong love, I am still getting used to Pentax - and, well, this lens is among the Helios 44 that makes me believe that it was a right choice.

First I should tell how I use the camera: I use the reversal film color mode, shoot RAW, and -1 exposure compensation is a must as highlights are not possible to save, yet shadows nowadays are. I generally have noisy photos as a result, yet it is my choice.

First, the samples page:


Infinity Focus: I believe that if one is going for a wide-angle lens, even though 28mm is 42mm on crop sensors and is not wide any more, it is because it will be mostly used on infinity focus. This lens, contrary to Sigma Super Wide (24mm 2.8) which I had just before, is very good to perfect on infinity in terms of sharpness and contrast. I was scared to use Sigma for landscapes and street photography, yet I do not worry with this one. Please see second and third photos.

Closer Shots: Although the lens is very good in infinity, it does not catch up with close ups. It produces okay to usable photos, but not amazing photos like Sigma did or Helios does. Do not expect great sharpness and amazing details, but do not think that the lens cannot do anything. In closer shots, sharpness is not the best thing with this lens. Please see the first photo.

Because I did not know how to use M series lens, I was shooting wide open first couple of days (and questioning myself when I was stepping down to f/8 and still having the same DOF with 3.5. Thankfully this wonderful forum solved my problem and I can use it fully functional now), and sharpness was all so good, excluding far corners which are the weak points of all lenses. Yet there is a problem - at the corners, even at 3.5, this lens is not bad, and very close to the center in real life situations (i.e. there is no difference like at f/2 and f/4 with Helios). There is no great increase in sharpness from 3.5 to 8 at the center, as it is amazing all the way, but the corners get almost equal to the center at f/5.6 already.

In short, if you shoot infinity, and if you want to be able to use it with confidence full open, this lens will not upset you at all (partly thanks to 3.5 though, as it is stop-down already compared to f/2 or 2.8 lenses).


Contrast-wise the lens is from very good to perfect for me. Anyway I shoot RAW, and I want to arrange contrast to my taste later in PP. Yet the lens produces good enough contrast, and in PP it becomes excellent. Come on, who wants a super-contrasty RAW photo anyway? Ain't it against the idea of shooting RAW? See the photos, and say that I am wrong - if you can!


Wow. Just wow. Nothing else. Close to Helios 44, but the Pentax colors - especially in reversal film color mode. I love the combination between the lens and the camera.


I find this lens rather amazing in terms of flare control. To test, I shot against the sun, putting the sun at the corners directly, and just out of the frame. To be honest, I found it better than the kit lens, and head-to-head with Helios. Maybe because I did not use a really flare-resistant lens before (well, maybe Nikon 18-105?), I do not think that there is any problem in terms of control. Yes, contrast declines some, and yes, colors go mad a bit (but not much in either one), but isn't this the case with all the lenses (well, maybe excluding the 10-20 times more expensive lenses, which I could never use)? See the third photo.

Distortion and Chromatic Aberrations

Distortion is very easily solvable in PS (Camera Raw 9.12 has the built-in profile which is good enough to fix easily) and I have no problems with it. However much I messed with Sigma super wide, I could not get the results I wanted. Chromatic aberrations have not been a problem for me even at 3.5, I did not see any in any occasion (maybe there are but I did not come across), so it is very good in that sense too.


If you want bokeh, 28mm, and especially 3.5, surely is not your thing. But I can say that I found bokeh decent. It is not, of course, wonderful as with Helios 58/2, but isn't this normal? There are 2-3 flower shots that I did, and I can say that I am surprised with them as I expected worse. They surely are not great, but come on, not altogether bad also. See the first and last photos.

Handling and Build

It is light and small, just like what a lens should be. Yet also metal, and I feel confident with it. Usual old Pentax quality (compared to modern, cheap, dirty lenses). If you know Pentax quality, which I assume you do, there is nothing missing here. I may just say that.

Focus and Aperture Rings

Focusing is easy, and the focus throw is short - which is another reason to like this lens. The "window" gives the scales 0.3, 0.4, 0.5, 0.8, 1.5, 3, and infinity which is cool enough. From 1.5 to infinity, it is equal amount of turn with 0.8 to 1.5, and as it gets closer, the turn is getting comparably longer (yet short enough). My partner, who does not like using manual focus lenses, can focus with this easily. Also the aperture ring is snappy. There are half steps between full stops excluding the last full step. So the aperture values are 3.5 - 4.5 - 5.6 - 7.1(?) - 8 - 9(?) - 11 - 13 - 16 - 22. Not a big loss - who cares about the difference between 6.3 and 7.1 anyway?


A 40-50 dollar lens cannot be without problems, so let us look at them.

First of all, this lens lacks the 3D capability of Helios. So there is some lack of depth in the photos. I personally do not like looking at "photos", I want to be able to "reach and touch the subject", and with this lens I do not have that feeling.

Resolution ain't amazing as I said above, yet for the price, and at infinity focus, I did not see one that is really great.

The more the aperture blades, the better. This lens has only five while even the kit lens has six, and the Helios has 8 (I have 44M). So the bokeh, if there will be some, will be ugly if there will be the pentagon shape.

It sometimes overexposes, sometimes underexposes. So you should keep an eye on it.

The biggest problem for me is the last one: I like using M42 lenses because there is no need to use the green button. I compose, camera meters, I set the exposure compensation, and I shoot. With this one I rely on the green button which is something I do not like. So I would prefer it to have M42 bayonet, but I cannot do anything for it. Right?


A very good quality lens, especially for the price. I am trying to find out the PP kings, and it already has shown me that it is worth the price paid to it. If you will find for rather cheap, a bit more expensive than Helios but no more, definitely get it. Compared to Sigma super wide, this is a great lens for infinity focus shots (although in close shots Sigma was a monster compared, especially with the sharpness and resolution).
New Member

Registered: June, 2017
Posts: 14
Review Date: July 31, 2017 Recommended | Price: $78.00 | Rating: 8 

Pros: Small size, metal barrel, smooth focus ring, great walk around lens
Cons: Ugly sunstars, heavy flaring, camera meter tends to overexpose scenes.
Sharpness: 8    Aberrations: 8    Bokeh: 6    Handling: 9    Value: 10    Camera Used: Pentax K1   

Seeing as there are no reviews of this lens on the K1, thought I'd chime in here. Recently purchased this little one, used but in excellent physical condition, for the equivalent of just about $78.00, in India.

I shoot product and food, and my style does not currently require me to have a wide angle lens. But I still wanted to try a wider perspective to see if I can work it into my style somehow. Soon i found this on the internet and bought it. Late that evening, tried some cityscapes and witnessed how my copy flares like nobody's business! So it became clear this is not for my night photography needs.

The next afternoon, I took it out to the local market, and that is where the lens began to give me good performance. Contrast is on the lower side, as is with both my M-series lenses, but stop it down to f/5.6 or f/8 and see it give you great results for social media! Also a very handy feature with the K1 is the ability to shoot in crop mode from the multi function dial on top, and that gives you super quick access to 28mm and 42mm equivalent focal lengths at will, which makes it all the more fun for casual street photography, and/or where the full 36mp resolution isn't very important to you.

I wouldn't recommend it for professional use, but that is simply because I wouldn't be changing my professional style based on this particular copy. But I plan to enjoy it while I have it, and so should anyone who wants to buy it, especially around this price.
Veteran Member

Registered: July, 2014
Location: Nagoya
Posts: 577

2 users found this helpful
Review Date: December 19, 2016 Recommended | Price: $80.00 | Rating: 8 

Pros: Usual solid M series, nice colours
Cons: Bokeh (it's a 28mm, colour me amazed), doesn't stand up to latest sensors

Not much remains to be said about this lens - it's a good 28mm, nice colours and the build is typical fantastic M series. On film it does a great job at the classic 28mm focal length and I have no complaints. On digital, it's a little more complex. On the older K-m this lens is a stunner and it's a combo I use often - something about the old but colourful 10mp sensor and this bright little lens just makes them a perfect match. Put it on the 20mp K-S2, however, and things start to fall apart - zoom in and even at f8 images look noticeably unsharp everywhere except from the centre, even with the APS-C crop. That is hardly a valid criticism, however - this lens was designed the best part of 40 years before the K-S2 came out, so unless Pentax's designers were particularly forward thinking, they certainly didn't do a bad job.

Thus, I recommend this lens, but with certain caveats - namely, if you're using a newer 20mp+ digital camera, you may want to look elsewhere in this focal length. But for the film users, and those (like me) who like to pair their classic glass with an older digital body, this lens will be a valuable addition to your arsenal.
New Member

Registered: February, 2016
Location: lake constance
Posts: 1

1 user found this helpful
Review Date: April 12, 2016 Recommended | Price: $50.00 | Rating: 10 

Pros: build, sharpness, light weight, color
Cons: none
Sharpness: 10    Aberrations: 10    Bokeh: 9    Handling: 10    Value: 10   

The Pentax M 3,5/28mm is a great lens for landscape and trips because of the advanced angle.
I always enjoy the neutral colors and in architecture photography i love that straight lines keep straight. The build is perfect as you know it from the "K" lenses.
Pick it, if you can - for low costs. I bought mine for ca. 50$, like new!

Registered: April, 2009
Location: Madrid, Spain
Posts: 9,744

3 users found this helpful
Review Date: October 19, 2015 Recommended | Price: $60.00 | Rating: 8 

Pros: Small, light-weight, very sharp
Cons: Slow, lacks 3D quality to results
Sharpness: 9    Aberrations: 8    Bokeh: 7    Handling: 8    Value: 8    Camera Used: K200D, K3   

This lens is very good, especially if simple sharpness is what is required. Build quality is typically superb for the M series. It's extremely sharp even wide open. Colour and contrast are very good but not excellent.

If you're into more normal focal lengths for landscape photography or you simply want a lens which is compact & very sharp wide open, then this is ideal. On a DSLR this means you can use it in A mode and not worry that your photos won't be sharp because you didn't stop down.

I have compared this lens to various other similar models.
  • Compared to M 28/2.8 (mark I). The f/3.5 version is sharper with much better colour and contrast
  • Compared to M 28/2.8 (mark II - optically identical to the A series lens). The f/3.5 is still sharper but no longer wins in colour and contrast - the f/2.8 is superior in these regards. I think the f/2.8 has more distortion though.
  • Compared to K 28/3.5. The K version is optically superior. It's just as sharp and has better colour and contrast and is capable of giving a 3D quality to photos, which the M version isn't. However, the K is much bigger and heavier.

In the end I sold this lens and kept the K version for sheer IQ and got an A 28mm f/2.8 for a smaller/lighter/faster version. I found that the images from the K version didn't need to be post-processed to give them some life and vibrancy in the same way as those from the M version. If you want a single lens though that's light, small and sharp wide open then the f/3.5 version is the best compromise available in the old manual 28mm lenses.

Edit: I got a second copy for a bargain price and it didn't focus to infinity, so be careful as this may be a common problem.

Some samples:

by Jonathan MacDonald, on Flickr

DSCF1080a M 28mm 3.5
by Jonathan MacDonald, on Flickr
New Member

Registered: October, 2015
Posts: 2

1 user found this helpful
Review Date: October 19, 2015 Recommended | Price: $54.00 | Rating: 9 

Pros: sharpness, little Chromatic Aberration, size
Cons: distortion,poor bokeh
Sharpness: 10    Aberrations: 10    Bokeh: 4    Handling: 10    Value: 10    Camera Used: A7s   

This is an excellent Landscape lens and I feel that many of the issues in other reviews here are down to either a bad adapter or damaged lens preventing focus to infinity.

I have both the Pentax-k 28mm f3.5 and CZ Distagon 28mm f2.8 to compare it to, and it holds it's own against both of them.

Stepped down, it offers excellent corner to corner sharpness and great colour and contrast. It has less CA than any other 28mm that I have ever seen and is much better than both the Distagon and Pentax-k in that respect.

The bokeh is obviously not too great with 5 blades, but this lens is not really about shallow depth of field anyway.

The only criticism that I have is that there is some distortion, which isn't noticeable for most landscape use, but may be a problem when shooting buildings etc.
New Member

Registered: May, 2013
Location: Jakarta
Posts: 2
Review Date: May 23, 2015 Recommended | Price: $30.00 | Rating: 8 

Pros: build, color rendering, excellent for landscaping photo
Cons: bad bokeh
Sharpness: 8    Aberrations: 10    Bokeh: 6    Handling: 10    Value: 10    Camera Used: K5, A7   

lucky i bought this lens in cheap price from ebay auction, this lens has excellent pentax color rendering, really like this for landscaping photography, it can produced very good detail of image

here are of my samples shoots on my flickr:
Senior Member

Registered: April, 2013
Location: St. Louis, MO
Posts: 114
Review Date: May 19, 2015 Recommended | Price: $59.00 | Rating: 10 

Pros: sharpness, color, x-factor, build quality, feel
Cons: bokeh not great
Sharpness: 10    Aberrations: 10    Bokeh: 6    Handling: 10    Value: 10    Camera Used: K-01   

I give it an overall 10 even in spite of the meh bokeh. I guess I'd give it a 9.5, but that's not an option. I don't expect this type of lens to be a bokeh monster, so with that in mind, this lens is really quite stellar when used appropriately.

The color is gorgeous. The sharpness is as good as one could want from a lens. The feel and build quality of these M's is legendary. The coatings are wonderful. It's not a fast one at f3.5, but I'm not using this as a fast, low-light lens. On my K-01 with focus peaking, it's quite easy to nail focus.

So with speed and bokeh aside, excellent sharpness clearly proven, what really makes this an exciting lens for me is the look of it, this x-factor. It just does something special, something vibrant and lifelike, an indescribable dimensionality that's very appealing to me.

Perhaps the best $59 I ever spent on a lens.

New Member

Registered: March, 2014
Posts: 1
Review Date: January 14, 2015 Recommended | Rating: 7 

Pros: Very sharp center
Cons: Needs to be stopped down for good edge sharpness
Sharpness: 8    Aberrations: 7    Handling: 9    Value: 8    Camera Used: Sony A7   

At f/3.5, the lens is very sharp in the center, with poor edges and corners (FF). Stopped down to f/5.6 the center becomes extremely sharp with improved edges, but the corners remain soft until f/8.

The lens has some visible distortion. CA is not a problem.

Handling is on par with most M primes, sturdy metal construction with smooth focusing. No wobbling or play whatsoever.
New Member

Registered: November, 2014
Posts: 2
Review Date: November 27, 2014 Recommended | Price: $55.00 | Rating: 9 

Pros: Small. Very sharp. Cheap.
Cons: Had bad copy
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 10    Camera Used: Fuji X-e1   

Cant get over how sharp this lens is. Rarely come up on ebay but If you can find one I would say buy it. Makes a great standard manual lens on my DSLR.

Had an infinity problem with a copy I recently bought off ebay. This lens is very well regarded and I was bitterly disappointed with the results I got with any subject more than 10 feet away. Not sure if it had been dropped or previouly badly serviced although it looked prestine. Nearly consigned to the back of the cupboard but with nothing to loose I partially dismantled it and actually removed the stop screw. That focus stop click may have gone and the focus ring turns / slips against the barrel past infinity focus a little but this mini gem has now become one of my favourite lens.
Veteran Member

Registered: March, 2007
Location: So Cal
Posts: 2,080

2 users found this helpful
Review Date: September 20, 2014 Recommended | Price: $45.00 | Rating: 9 

Pros: Flat field, clean all the way across on a full frame sensor, minimal CA, sharp
Cons: dark corners on full frame, five aperture blades can make for ugly bokeh in certain situations.
Sharpness: 10    Aberrations: 8    Bokeh: 3    Handling: 8    Value: 10    Camera Used: Sony a7R 36mp full frame   

i've mounted nearly a dozen legacy 28mm primes on the sony a7r, and the smc pentax-m 28mm f/3.5 is the best i've seen so far for stopped-down landscape shots.

you'll have to download a 21mb image comparison to see the differences:

SMC Pentax-M 28mm f/3.5 lens test

what's surprising is how clean the sides are on ff... the pentax k3 will have higher pixel density than the a7r, but i bet that the center of this glass can resolve it.

~f/10 appears to be the best compromise on the a7r.
New Member

Registered: February, 2014
Posts: 7
Review Date: February 22, 2014 Recommended | Rating: 8 

Pros: Handling, sharpness, contrast, build quality
Cons: Could be faster, bokeh could be nicer
Sharpness: 8    Bokeh: 6    Handling: 10    Camera Used: ME   

Just borrowed this for a few rolls, so can't comment on price / value.

Handles like the other lenses in this line: very nice.
The copy I had wasn't as super-smooth as the 50mm f1.7 for example, but still a joy to use.

It's sharp, at least stopped down a bit, and as others said - the images "pop" -
the lens delivers nice contrasty and rather vivid images.
Very nice.
Inactive Account

Registered: November, 2013
Posts: 9
Review Date: November 26, 2013 Recommended | Rating: N/A 

Pros: Takes the "Oscar" for my best lens in my collection
Cons: None
Sharpness: 10    Aberrations: 10    Bokeh: 7    Handling: 10    Value: 10    Camera Used: K5. K10D   

Takes prize place in my vast collection of manual vintage pentax lenses
I have 3 of these beauties .
Even the one I have that has some scratches on the lens pushes out stonkinly good sharp images.

So so so sharp after f8
Don't expect bokeh with this lens it just does "sharp"
Better than the 28mm Super Takumar
Need to be a little careful with metering for best results .
Seems to be better on the older sensor of the K10 for crisp landscapes than the CMOS sensor on the K5

I LOVE THIS LENS and worth the extra pennies second hand. I picked mine up for 70

For some strange reason I slapped this on my Canon 30D it hits the sweet spot so good that I have one on the canon all the time . better than any canon lens I have seen even the L lenses .

A MUST have buy. Don't hesitate to buy one if you want sharp images this wins hands down.
New Member

Registered: August, 2013
Posts: 2
Review Date: August 5, 2013 Recommended | Price: $106.00 | Rating: 10 

Pros: small, incredible sharp, build quality, colors
Cons: slow
Sharpness: 10    Aberrations: 10    Bokeh: 9    Handling: 10    Value: 10    Camera Used: K20d and K5   

I bought this Lens from a seller on ebay. I must admit it wasn't cheap, but boy it is worth every penny. I use it mainly on my K5 as a small and leight Lens (almost like a limited) for landscape work, which produces astonishing sharp results even wide open.

Other than the majority of reviews, my copy of the SMC M 28 3.5 is all up to my K 28 3.5 and even outperforms it from f3.5 to f5.6.
Even more astonishing is the fact that it beats the Tamron 17-50 f2.8 in all aperture settings! (both focused via Live-View). The only strange thing is its color rendition. During day it produces rich colors full of contrast, but somehow during night or dawn, everything gets a strange blueish rendering which can hardly be compensated by post processing.

Distortion is quite low in its sweet spot (APS-C). It might be an issue on full-frame or film, but i never tested it.

Lens flare seems to be well controlled, however with open aperture contrast is strongly reduced when taking pictures directed towards the sun. Stopped down to f8 the problem is gone.
In terms of Bokeh i say its a 9, simply because you can not expect a f3.5 Lens produce creamy background like a 50 1.2. On the otherhand, for f3.5 it is not nervous.

All in all: comparing its size and sharpness it is the perfect carry-around lens during day time, when more than f3.5 isn't needed anyway. Said that, I will never sell this lens, that's for sure!
Veteran Member

Registered: November, 2012
Posts: 963
Review Date: June 18, 2013 Recommended | Price: $45.00 | Rating: 9 

Pros: Sharp, great Pentax colors, light and small
Cons: Slow
Sharpness: 9    Aberrations: 9    Bokeh: 7    Handling: 9    Value: 10    Camera Used: KX   

I got a mint copy of this lens.

Unfortunately, initially, it wouldn't focus to infinity. A thread here in this forum taught me how to correct the lens.

This lens has also taught me that basic axiom to never judge a lens without a tripod.

I knew that the FOV is good, but at first, I was very disappointed with its resolution and its general softness. Then I tried mounting it on a tripod, and presto! this lens, I discovered, is a keeper.

It's a slow lens, handheld, it will be difficult to get a sharp image especially under artificial lighting, but give it enough light, and it shows its true Pentax colors.

I just love this quirky little beast.
Add Review of SMC Pentax-M 28mm F3.5

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