Pentax-m 40mm

Pentax-M 40mm f/2.8 and Pentax MX – imperfect, but pocketable!

In my recent Pentax MX review I touched on the fact that I’d only really been shooting it with the Pentax-M 40mm f/2.8 pancake lens. This is a lens that seems to divide opinion a little bit, so I thought I’d share some of my currently-slightly-grumpy-about-photography feelings toward it.

I’ve been reviewing gear for quite a few years now. If you include my previous blog and the forum I used to run, it’s something like 12 years, though the last 6 1/2 years it’s been a lot more intensive. In that time I’ve interacted with a hell of a lot of people, and whilst there is obviously a scale with an infinite amount of variables, I’ve found that photographers can be pretty much divided into two groups when it comes to lenses. Those who do care about lenses, and those who just shoot with the focal length they need and don’t much care beyond that as long as it fits on their camera and does broadly what it’s expected to.

There is of course nothing wrong with either of those perspectives, though personally, for a long time now, I have found myself on the caring-about-lenses side of the fence. In short, for me, lenses are a vital part of fulfilling my vision. A while ago now I wrote a post about defining the perfect lens. In that post, I suggest that the perfect lens is the one that allows the photographer to fulfil their individual goals. It’s not about line pairs, MTF charts, flatness of field etc, but about how the image is rendered by the lens and how important it can be to understand that rendering when creating an image. I go into a lot more detail with examples in that post here.

When it comes to what I usually look for from a lens, for the most part at least, I have two preferences. I like the ultra-contrasty modern rendering I get from my collection of modern Zeiss ZM lenses, and I also like the rounded glowy look I get from old Sonnar lenses. I’ve talked about both of these preferences quite a bit on this website. A little while ago though I started noticing another preference rearing its head. This was a preference for just not really giving a crap.

As I think I’ve made it abundantly clear recently, my feelings toward gear and indeed taking photos has been at a low ebb. As I talk about in the first post of this series, I picked up the Pentax MX initially as I found it relieved me somewhat of my usual habits around sometimes thinking about gear too much.

First Roll with a Pentax MX

Significantly, the Pentax-M 40mm f/2.8 came part of that package. It came as a lens that – at least in terms of the photographic outcome – I didn’t really give a crap about. I just wanted something that fit on the camera, was as small as possible to match the camera, was a focal length I was happy with, and was fast enough for the type of snapping I wanted to do.

A different set of ideals

Actually, in some ways, this set of ideals isn’t entirely alien to me. It’s the set of ideals that I largely apply to shooting when I’m using a point & shoot camera. Though I can’t deny that I haven’t been suckered in by point & shoot cameras with name-brand lenses attached to the front of them in the past, for a large part the mentality I have when I approach photography with a point & shoot camera is very much one of not giving a crap about the lens. The reality is, the massive majority of point & shoot lenses are “good enough” – as Mike quite eloquently points out here. The same can be said of most camera lenses in fact. Which is why a lot of people are able to take the stance of not giving a crap about their lenses, regardless of the type of camera they shoot.

What is alien to me is combining the not-giving-a-crap mentality with a fully manual mechanical camera. Usually if I’m stepping out of point & shoot territory I’m stepping into a world where I care more about how my photos will be rendered. On this occasion though, the pieces of the puzzle have added up to something different.

On this occasion – again as I talked about in the first post in this series – I was looking for a camera that I could easily carry and that was fully manual. I went into all the details why in that first post, but the short version is that I just wanted a camera and lens that I could take anywhere with little thought but that also allowed me to connect with the process of actually taking a photo. I wanted point & shoot size, with full manual control.

The Pentax MX offered the size and the control, the Pentax-M 40mm is the smallest lens for that camera so that’s the one I went for. The choice of lens had sod all to do with the way the images were going to look – I assumed the results would be good enough, and that was all I cared to achieve.

First Roll with a Pentax MX

This might not seem like a big deal to those of you out there who regularly don’t give a crap about the minutia of your lens’s optical properties but to someone who reliably does give a crap about this sort of thing, this sort of approach felt slightly alien. Alien as it felt though, it fit perfectly with my current mentality.

The Pentax-m 40mm f/2.8

That might seem like longer-than-usual preamble, but it feels necessary given the circumstances. This is mainly because it feels like I’ve freed myself from my usual approach to lens reviews where to greater degree I focus on lens character over and above any other factor. This is a lens that’s seems to me to not have been designed to be reviewed how I would normally review a lens. Reviewing Pentax-M 40mm f/2.8 – for the most part at least – feels more like an exercise in understanding compromise. Not only does its small size compromise potential image quality, its small size also compromises handling.

Really, therefore, the questions this lens poses are simply whether or not its small size does feel like an advantage in use, and beyond that does the advantage that brings outweigh the compromises it otherwise presents. In other words does it take a good enough photo and handle well enough to be taken seriously as an option over and above a lens such as the Pentax-M 50mm f/1.7 which isn’t much larger?

Image quality

This is where I think my preamble is most relevant to this review. Quite genuinely, reflecting on the image quality of the Pentax-M 40mm f/2.8, “good enough” are the first and pretty much only words that come to mind.

Very little about the way it has rendered the images I have so far taken with it has disappointed me. But equally very little has made me even contemplate the image quality at all. There’s been a couple of photos which I assume were taken wide open that I’ve noted as being a little soft, but other than that, for the sort of snaps I’ve been taking it’s performed plenty well enough for my needs.

First Roll with a Pentax MX

The important thing though is to put those needs into context. The context here – if I’ve not made it clear enough already – is one of not really giving a crap. I wanted to take photos of my kids and snaps when I’m out and about, so ultimate image “quality” isn’t really a high priority. I’m shooting with a higher-grain film too, so even a basic need for “sharpness” is less relevant.

Reading other reviews people talk about Pentax-M 40mm needing to be stopped down for adequate sharpness especially into the corners. There’s talk of bad bokeh (not uncommon in pancake lenses) and heavy vignetting. I’ve read that on digital cameras it’s even worse in all these regards.

So which is it? Poor, or “good enough”? Of course, the answer is quite simple. It depends on subject matter, choice of media and overall needs. For me, for what I’ve used it for, as I’ve said, “good enough” have been the words that most readily come to mind.

First Roll with a Pentax MX

The handling

It is certainly fair to say that any lens this tiny is going to be harder to use than an even fractionally bigger lens. This thing is minuscule in terms of how much it projects from the body of the camera, and with that small size obviously comes small focus and aperture controls.

With the camera to the eye, it actually feels a lot easier to grab the aperture control than it does to grab the focus control. This indeed seems to be a primary complaint that most people have with the Pentax-M 40mm, and I must admit, I’m still not completely immune to trying to focus with the aperture control – and that’s despite using it a fair amount now.

Pentax-m 40mm

Again, if I were shooting something “important” – something where it was vital that I was able to take spur of the moment shots – I probably would find this a minor hinderance sometimes. But somehow, photos of a drinks can stuck in a fence don’t feel like they encapsulate what the great HCB was talking about when he coined the phrase “the decisive moment”.

First Roll with a Pentax MX

And even shots that maybe get slightly closer to those moments have just required a bit more thought and preparation.

First Roll with a Pentax MX

And really, would I have cared if I missed the moment this chap walked under this tree? Not really, no. I’m not exactly redefining the genre of street photography here am I? I’m snapping for the sake of snapping, and again, the slightly compromised handling hasn’t really gotten in the way of that.

The size advantage

I’m sure it’s pretty obvious by now that I’ve been working toward talking about how much I’ve enjoyed the Pentax-M 40mm f/2.8 for its tiny size. The 50mm f/1.7 really is only a tiny bit bigger (it’s actually about twice as long, but that’s splitting hairs a little…) but there’s just something about shooting a camera and lens that were both designed with a primary focus on smallness of size.

The only single issue I’ve had – and it’s a bit of a stretch to call it an issue really – is that the weight of the lens is so small that when carrying it on a strap the camera has a tendency to tilt up at the sky which can make it a little less comfortable to carry. Fortunately, we’re now in the time of year that allows me to wear a coat. Coats mean more pockets, and the Pentax MX and 40mm f/2.8 combo fits with more than a little ease into said pockets. This has meant the strap – and therefore that particular handling issue – can be left at home.

Caveat emptor

All of the above said, I feel like I should just emphasise the point that if you asked me if I’d choose the Pentax-M 40mm f/2.8 for something more “important” than snaps, I’d probably look elsewhere. It’s good enough for snaps, and it’s satisfied my recent need to not think about a lens, but were I shooting something for work – or anything where I felt like I could justify carrying something bigger – I’d probably choose the bigger “better” lens. In fact, quite simply, I’d likely choose one of my Zeiss ZM lenses.

But that’s not really the point here. I’m sure regular readers will be able to detect the grumpy tone I’m writing in at the moment. I’ve even had a couple of comments from readers suggesting I cheer up and stop bringing everyone down with the lack of joy I currently have for photography. I’m not in the mood to be thinking too deeply about things like optical quality all the time. So when it comes to the Pentax-M 40mm, I’m happy with the slightly compromised image quality because it doesn’t matter for the type of photos I’m taking. What ultimately matters is that I’m taking them, and I’m taking them because for the time being I’m happier carrying a smaller camera and lens.

Pentax MX snaps

Final thoughts

Whilst everything I have written here has all been very specific to my current needs, desires and indeed mood, what I hoped to achieve by sharing all this is the point that this lens – despite what you might read about it – is perfectly adequate if your personal set of needs meet with the set of compromises within which this lens was designed.

The Pentax-M 40mm f/2.8 is a small lens that was seemingly designed almost entirely for the sake of smallness. As part of that design process, it is fair to say that both optical quality and overall handling have been sacrificed simply for the sake of creating a lens that’s almost impossibly small.

For many these compromises will be a step too far, and I’m sure for them the 50mm f/1.7 or 35mm 2.8 make for better options. For me though – and I imagine a lot of other people out there who just want something small and easy to carry – this lens offers something unique.

Combined with the Pentax MX, the Pentax-M 40mm f/2.8 lens offers fully mechanical, manual film photography in a package that’s barely bigger than some of the point & shoot cameras out there – the optical quality is up there with those sorts of cameras too. And this has been exactly what I’ve needed in my life recently. Does any of this make the Pentax-M 40mm f/2.8 the right lens for you…? I dunno, who am I to say… but if you don’t give too much of a crap about your optical quality and crave something pocketable, it might be worth giving it a go!

Contribute to 35mmc for an Ad-free Experience

There are two ways to experience 35mmc without the adverts:

Paid Subscription - £2.99 per month and you'll never see an advert again! (Free 3-day trial).
Subscribe here.

Content contributor - become a part of the world’s biggest film and alternative photography community blog. All our Contributors have an ad-free experience for life.
Sign up here.

About The Author

43 thoughts on “Pentax-M 40mm f/2.8 and Pentax MX – imperfect, but pocketable!”

  1. Interesting certainly. I’ve had an experience the past few months where I have carried a rather different camera to what I normally do: a Canon EOS 50e with 40mm f/2.8 (!) rather than one of two Pentax MXs (!). I got an EOS 300v based on this article ( ages ago, then finally got the lens in August. I tested both the lens and 50e before I took it on holiday then never put it down. I wasn’t expecting to mesh so well with autofocus and control dials, rather than the MX I’ve used for my first two years. I think it is that I care less about it getting damaged and the Canon 40mm is similarly tiny, so I carry it more.

  2. I enjoyed this, longish but a succinct Hamish-like conclusion: horses for courses Too much over thinking and self-referencing happens in photography blogs with a tendency to conclude that most expensive or newest is best. We are saved form that here, bravo!

    1. Thanks Des, though I can’t claim to not overthink… this blog would be less without my overthinking, I’m sure ????

  3. I had the same lens and found that resting the camera in my left hand and just focusing with my index finger got around constantly changing the aperture by mistake.I was happy enough with the shots but I just preferred the images from the 50mm, to the point that I couldn’t honestly say where I put the 40mm.

      1. Yep. the 1.7, its a lovely lens. The MX and ME Super are, relatively speaking, so small and light that the extra weight/size of the lens doesn’t really make a difference to me (I normally lug a Nikon F4 around!).

  4. Great review Hamish!
    I chose the 40mm Pentax because of its size too. When I bought my X-Pro1 I wanted to use a compact lens, so decided on the PK-mount system to use with an adapter. And the 40mm is indeed compact! I can only think of the Industar 69 being that compact.

  5. Interestingly, pretty much everything you said about the Pentax 40mm can apply to the Fuji 27mm pancake – ‘ok’ sharpness, lots of vignetting, kinda awkward to handle, but perfect when you just want something small and discreet. Also it makes my XT2 error occasionally, but that might just be my copy of the lens 😀

    1. I picked up that lens last year. Got it for a good price and I’ve used it a fair bit when I’ve wanted to pocket the X-T10 (which, incidentally, is exactly why I use the 40mm on the MX). It does the job but it’s just kind of…unremarkable. I find the Pentax 40mm nicer.. The problem I have with my Fuji X lenses is that as wonderful as they are, the 18-55mm zoom makes the rest a bit redundant. It’s so close to the primes in terms of image quality that 95% of the time it just doesn’t make sense to take anything else.

  6. In the end as in the beginning. 🙂 I’m familiar with this plight of sorts. Since Sonnars and ZMs are mentioned here I’m comfortable suggesting my solution to the MX portability quest, which is the FA43/1.9 Ltd. Smaller and lighter than the 50/1.7, faster and better handling than the 40/2.8, with images that the pull that pants off of both. An AF lens of course but manually focusses surprisingly well. Add the lens hood from a DA40mm and it achieves quite the low-profile. Naturally you pay for all of this with FA43, but twas ever thus. 🙂

    1. Yeah, you’re not the first to make said recommendation… I have them on watch on eBay, but I’m trying to be a bit more frugal at the moment :/

      1. I’m sure not. Yup, I can relate. (We all can). I resisted the ‘three amigos’ for a good number of years (I’d lusted over the 31 for a long time) and finally gave in. Picked up one, and within a year had all three as a result. They are *that* good. But the 43 is something truly special, at least to me.

  7. Impressively small lens, evem if imperfect, and I agree that sometimes it’s better not to obssess about lens quality and just shoot wth something adequate and convenient. I’ve just bought an unusual roll of B&W film (Santa Rae 1000) at The Photographers Gallery in London which I visited for the first time last week, and I’ve been wondering whether to load it into the best camera/lens combo I have, or just use a satisfactory point and shoot. Right now I’m not sure I can really be bothered lugging around something quite big, so I’ll probably go with a small compact in my pocket with an OK lens and just enjoy taking snaps.

    1. Yeah, that sounds about my attitude at the moment. Trying to worry less and snap more. Unfortunately I’m still snapping less, even if I’m worrying less… I’ll get there though, I’m sure…

  8. I had an MX with this lens. It was indeed good enough, the photos were fine, the size was just about small enough to be pocketable, but it is memorable for one thing. Namely, I went to photograph a church memorable for its gargoyles, by amazing coincidence they were being restored and the restorer turned out to be a fellow Rollei owner (which I’d also brought). I couldn’t go up the scaffolding for insurance reasons but he offered to shoot the best gargoyles for me. So up he went, but minutes later he was down. The MX had died and was beyond revival with new batteries. So back it went to seller, the lens sits unused and I still think of those gargoyles that are now out of reach.

      1. I decided that with everything else I have this was a warning from providence to avoid buying yet another camera and lens system. Instead I bought a Voigtlander 40mm Ultron f2 for my Nikons and it is altogether lovely for IQ and handling, if somewhat more expensive.

    1. Yeah, along with the 43 I have a saved search on eBay … I used to want one for my Nikons, but never took the plunge

  9. I share your attitude toward this lens as a lens. Good review. One use for this lens surprised me; it is quite good on a 16mp APSc digital camera. With the soft edges cropped away and the useful 60mm “equivalent” field of view it produced very nice rendering.

    1. I’m thinking about adding the 100mm to mine. If I’m going to shoot an SLR I might as well take advantage of how much easier telephoto lenses are to shoot with them… how did you rate the 85?

  10. This goes totally against the spirit of this review but there are other options out there of course. If you absolutely must have a pancake on an Pentax M camera that excels at wide open, there’s always the Voigtländer 40mm F2 Ultron SLII. Mind you, it costs about 6 times what you’d pay for a PK40/2.8. A bit less if you get the M42 (SL 1 ) version with a conversion ring, if you can be bothered with stopdown metering.

    Another more feasible alternative is the Auto Revuenon 45/2.8 which is better than the Pentax and costs about the same. Though now you’re rubbing elbows with 50mm. But at the end of the day, the PK40/2.8 is a fine F8 and be there kind of lens.

  11. I think you sum it up perfectly with –

    “What ultimately matters is that I’m taking them, and I’m taking them because for the time being I’m happier carrying a smaller camera and lens.” Surely that all that matters – when you look back at the images surely it will be the memories the lens captures rather than corner sharpness you will be interested in.

  12. I got my first MX in a local charity shop, boxed… and they were offering a 40/2.8 as well for a measly sum of, oh, I dunno, maybe £40. I tried it on the camera, and found the handling just too awkward, so didn’t buy it. Since then, I’ve several times thought, a 40/2.8 is just what I need (after using 40mm lenses on a Canonet and a Leitz CL), then looked on fleabay and shrieked in disbelief! No way am I gonna pay the best part of £100 for a handling problem… I just wish it was a little bigger, rather than the snub-nosed pug it actually is.

  13. I enjoyed that. Thank you. Writing is obviously something you can find solace in, while waiting for your inner child (for that is what sees the wonderment) to come back. I’d write like buggery if I was you. It will keep you semi-satisfied and we get some decent writing on photography. Everybody wins.

    Thanks again.

  14. I’d imagine its kind of similar to how I feel with taking my Nikon FA and 45mm f/2.8P out. Compact and certainly easy to carry around. The lens is less than perfect (but still pretty good especially if you like tessar style rendering) but the convenience of carrying the lightweight kit outweighs the relatively small negative aspects.

  15. Thanks Hammy for an excellent article. It made me realise that I’m one of those who doesn’t really give a crap about the lens.
    Yes that is obviously weird coming from someone who loves Zeiss lenses. I like the look of the results but that’s a bonus. For me the way the camera handles is important. Being able to change the shutter speed and aperture without taking my eye from the viewfinder etc.

    Let’s face it, the biggest image we see is usually a 6×4″ print. The quality of the lens is probably not an issue. For me the faster the better in that it is better to get the shot than the quality of the result. There are lots of situations where f2.8 is not enough which means that lens is not good enough.
    The other thing I realised this summer is, like you how much I enjoy the point and shoot camera. Content is so much more important than quality. Think about all of the iconic photographs. Yes I’m teaching my granny blah blah but isn’t there too much emphasis on the technicalities?

  16. I’ve got this combo. One of my few genuine second hand ‘scores’ was finding an MX with the 50mm f/1.7 for £15 at a car boot sale. I gave him £12, not realising how sought-after black MX’s were. I intended to sell it on, as my Canon A-1 theoretically made it redundant, but it just felt so ‘nice’ in use compared to the Canon I couldn’t part with it. Picking up the 40mm pancake (shout out to West Yorkshire Cameras) gave the MX its tenuous niche in my arsenal – pocketable SLR.

    A lot of people feel the pancake is overrated and feel quite strongly that it’s not worthwhile over the 50mm. I like it and it’s definitely the lens I use most on the MX. I find quite a few of the images I take with it really jump out at me. Not because of sharpness, but there’s something about the field of view and the way it renders that give it an immediacy and a slight dreaminess that’s just ‘right’ for what I want to achieve. It’s safe to say I’m not really a lens person, though – good enough is good enough as far as I’m concerned. I don’t have any real issue with the handling, either – the MX’s handy ‘periscope’ window showing the aperture means you know right away if you’ve got the wrong ring.

    I have four K-mount lenses: the 40mm, the 50mm f/1.7, a Helios 44k and a Rikenon XR 28mm f/2.8. The 40mm is the one I use most, due to its convenience and my fondness for its rendering. Next would be the 28mm, which is a solid performer and a nicely constructed lens (just watch out for the non-XR Rikenon’s, which won’t disengage from Pentax cameras!) I reach for when I want something wider. Then it’s the Helios for Bokeh portraits and slightly grungy look. Finally it’s the fifty, which looking at the images I can see is technically streets ahead of the rest but I just very rarely shoot with it. I find the 50mm FoV a touch tight and I guess I prefer a bit of character in my lenses.

  17. Way back in my camera shop sales days, we had the 40mm on an ME or ME Super in the show case – and that drew people in somewhat toward the brand. (Most of our customers weren’t likely to consider the MX – which is truly unfortunate.) All of us knew that lens was far short optically compared to the fine 50s. Although I do think your copy is a bit weaker than normal based on the images posted. Also, even though the optical formula is likely the same with the current digital Pentax 40/2.8 pancakes, these newer versions are amazing good in their rendering and adequately sharp (my IQ priorities are generally elsewhere than ultra-sharpness). On crop, 60mm equivalence is kind of nowhere, though.

    1. The odd thing about the new ones is that they claim they’re only for apsc, when they seem to provide good coverage on “full frame”… I’m not sure why they’d say that if the formula hadn’t changed slightly?

  18. Hi Hamish,
    Enjoyed your thoughts (on the 40mm) as always. I have the same setup the 40mm (given to me by a friend) and the MX that I purchased, along with 2 lenses, from Goodwill for $30 cdn which would be about 1 pound 50 in your money ha ha. Some poor chap must have passed away his family dumped his Pentax gear at the Local charity shop. I bought everything in the showcase. The only difference is that I have made my 40 a bit bigger by adding a filter – they are all 49mm filters aren’t they? Anyway this allows a little something to help by grabbing the filter and sliding my fingers back for focusing. This is not a slim filter, however, I am sure that you can get one of those easily enough. If you never use filters then you will have to carry on. My MX is silver and the shutter speed dial turns easily with one finger, but the 40 is a bit stiff at mfd. I hope that by now you have gotten your photo groove back and are out there happily snapping away (using social distancing of course) with the 40 or something else. Keep writing and keep shooting. The End.


Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Scroll to Top