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SMC Pentax-M 50mm F1.4

Reviews Views Date of last review
107 545,766 Thu October 1, 2020
Recommended By Average Price Average User Rating
99% of reviewers $76.22 9.30
SMC Pentax-M 50mm F1.4

SMC Pentax-M 50mm F1.4
SMC Pentax-M 50mm F1.4

The SMC Pentax-M 50mm F1.4 is the fastest and largest of the 50mm standard M lenses. It is nevertheless more compact that most other M lenses, and smaller than the original SMC Pentax 50mm F1.4.

SMC Pentax-M 50mm F1.4
©, sharable with attribution
Image Format
Full-frame / 35mm film
Lens Mount
Pentax K
Aperture Ring
Yes (no A setting)
Automatic, 8 blades
7 elements, 6 groups
Mount Variant
Check camera compatibility
Max. Aperture
Min. Aperture
Min. Focus
45 cm
Max. Magnification
Filter Size
49 mm
Internal Focus
Field of View (Diag. / Horiz.)

APS-C: 32 ° / 27 °
Full frame: 47 ° / 40 °
Various types
Dedicated hard case
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Diam x Length
63 x 37 mm
235 g
Production Years
1977 to 1984
Engraved Name
smc PENTAX-M 1:1.4 50mm
Product Code
User reviews
Lens was sold without hood. Several hoods will fit like PH-S49 (50mm) and screw-in type metal and folding rubber hoods
Manual FocusAperture RingFull-Frame SupportDiscontinued
Price History:

Add Review of SMC Pentax-M 50mm F1.4
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New Member

Registered: June, 2020
Posts: 11

3 users found this helpful
Lens Review Date: October 1, 2020 I can recommend this lens: Yes | Price: $110.00 | Rating: 10 

Pros: Beautiful bokeh, razor sharp at f/5.6 to f/8
Cons: Wide open f/1.4 performance lacking, dramatic improvement at f/2 though
Sharpness: 10    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 9    Camera Used: Pentax LX   

As expected for a Pentax nifty-fifty, the handling is very smooth and enjoyable. It feels good in the hand and the focus throw is just right - not too long, not too short, and allows for efficient and accurate manual focusing. The lens feels reassuringly solid and well built, and is compact enough to not look out of place on most SLR's. For handling I cannot fault it.

Bokeh is probably the biggest advantage this lens has. It's beautiful, being able to render even the harshest backgrounds into creamy smooth silk with spherical round balls of light. The change from in focus to out of focus areas is soft and gentle and very pleasing to the eye. I've only seen better bokeh in a lens that cost several times more.

Sharpness and performance

f/1.4 - Wide open the performance is unfortunately a little lacking in sharpness and contrast. Some people find the f/1.4 aperture to make perfectly good images. Perhaps for some artistic portraits with the great bokeh it can work, but by my standards I find it not sharp enough for usable images and I avoid it when ever possible, especially considering the massive improvement there is at f/2 just one stop higher.

f/2 - Dramatic improvement in sharpness especially in the centre. Contrast is still lacking a little but the overall image quality is highly usable and makes wonderful pictures, doubly so when you take into account the bokeh which is still excellent. Colour rendition is decent.

f/2.8 - Sharpness spreads across the frame and into the corners. Contrast picks up massively. Colour rendition on film at this aperture and further is stunning.

f/4 - Slight improvement in sharpness across the frame. Other quality performance (contrast, colour, etc) remain excellent.

f/5.6 - Slight sharpness improvement again. By now the image is tac-sharp from edge to edge. Images are so crisp and sharp they look like you could reach out and touch the objects in the picture.

f/8 - The same as f/5.6 - I see no difference other than the depth of field.

f/11 to f/22 - Performance remains excellent though diffraction starts to set in as you stop down further.

I find the most likely competitor to this lens to be it's little brother, the Pentax-M SMC 50mm 1.7. At the middle apertures of f/5.6 and f/8 you'll see very little difference if any - both razor sharp. Perhaps if you screw your eyes up and zoom in you might find the 1.4 version just a hair sharper.
They are both good at f/2 and share similar performance at f/2 and f/2.8 (in my opinion). So why would you choose the 1.4 version considering it costs more? Mostly, I would argue, for the bokeh. There is no avoiding that the 1.7's bokeh can be awful (yes, it's true), whereas the 1.4 has a smooth silky bokeh in another league.

Whether you choose this 1.4 or the 1.7 as your standard 50mm lens will depend on what you want out of your lens and what you'll use it for. You can't go wrong with either, they're both great, but for dreamy backgrounds the 1.4 will be hard to beat.

Final thoughts

I would argue the best usage for this lens is street photography, travelling and walk-arounds - much like most 50mm's. But the sharpness at f/5.6 and f/8 (two very commonly used apertures) is out of this world and cannot be overstated, making travel and street photos of an extremely high caliber. The good low light performance (when not used wide open) and the delicious bokeh make it a great available light lens too.
New Member

Registered: June, 2020
Posts: 2
Lens Review Date: July 27, 2020 I can recommend this lens: Yes | Price: $40.00 | Rating: 7 

Pros: Crazy sharp from F4 above, excellent contrast, small and compact, well built
Cons: Color fringing when using macro tubes up to F4
Sharpness: 7    Aberrations: 7    Bokeh: 7    Handling: 9    Value: 7    Camera Used: EOS 60D   

I bought this lens few months ago, in perfect condition. I am using it for portraits and for close up. I like it despite its weakness when using macro tubes. With macro tubes it has to be closed to F4 otherwise too much fringing in out of focus areas. Using it for portraits it is perfect from F2.4 on.

Pictures below...

New Member

Registered: June, 2018
Posts: 2

2 users found this helpful
Lens Review Date: January 21, 2020 I can recommend this lens: Yes | Price: $85.00 | Rating: 10 

Pros: High sharpness and contrast, excellent build and handling.
Cons: Aberrations wide open
Sharpness: 10    Aberrations: 8    Bokeh: 10    Handling: 10    Value: 10    Camera Used: MX, X-T3   

Out of all the Pentax 50mm 1.4's, this version is my favorite. It's got the right size and shape, handling and look, and image quality and performance. In terms of image quality, it's very similar the old m42 SMC Takumar version but without the rare earth metals. That is, decent central sharpness wide open with aberrations starting in the mid-frame and turning into heavy aberrations at the edges and corners (average for lenses of this design). It also controls fringing OK for a fast prime at bright apertures. Close down the aperture and by f/4 it's excellent across the frame. Flare control isn't as great as the 50mm 1.7M but it's good for a fast 1.4. All in all a solid lens and an important part of my 4-lens MX film kit.
New Member

Registered: December, 2019
Posts: 11
Lens Review Date: December 31, 2019 I can recommend this lens: Yes | Price: $40.00 | Rating: 10 

Pros: Fast, Cheap, Compact, well-built
Sharpness: 9    Aberrations: 10    Bokeh: 10    Handling: 10    Value: 10    Camera Used: Pentax MX, Canon 5DmkII   

Bought along with a SMC Pentax-K 300/F4 for $110 (dealer was asking $80 each, I split the $110 here based on the average price on this site)

a great little lens. creamy and soft at F1.4; it'll win no awards for sharpness wide-open, even dead center. But stop it down and you get some excellent image quality that keeps improving all the way to F8 or so. Really not much more to say; if you don't have a good 50 yet, this is an excellent one to grab. I'm not sure I'd spend too much time and effort upgrading from the same-generation 50/1.7 to this; it's a bit more bulky and the half stop isn't really going to buy you all that much compared to, say, pushing your film or cranking the iso on digital. An exception might be if you want to do (crop-sensor) portraiture at wide open for creamy softness, but to be honest I think I'd prefer a portrait stopped down at least some to wide open. the minimum focal distance is surprisingly short and you can capture some pretty dynamic shots up close. Infinity focus is also close, another point in favor of stopping it down and using it to capture a relatively literal image.

Portra 800 on a MX, stopped down to at least F4 (don't remember specific settings)
Loyal Site Supporter

Registered: September, 2017
Location: Medellín
Posts: 1,284
Lens Review Date: December 23, 2019 I can recommend this lens: Yes | Price: $80.00 | Rating: 10 

Pros: Small, 49mm filters, handling, build quality.
Sharpness: 9    Aberrations: 8    Bokeh: 9    Handling: 10    Value: 10    Camera Used: Film cameras, K-5   

Tried a friend's and the handling convinced me to get one myself. It's a really nice lens if you like manual focus and to take your time. Live view definitely helps for critical focus, as well as a split prism and/or microprism focusing screen. It's noticeable heavier than the M 2 or 1.7 and the FA versions.
New Member

Registered: October, 2019
Posts: 2
Lens Review Date: November 5, 2019 I can recommend this lens: Yes | Price: $35.00 | Rating: 10 

Pros: Excellent low light results
Cons: none

Another great lens. Great sharpness, provided you are adept at dialing in focus manually.

- Pentax-F 50mm F1.4
- Pentax K-50 DSLR (16.3mp)
- mounted on tripod
- aperture priority
- ISO 100
- white balance set to AWB
- focus peaking enabled on camera
- using manual focus assist / check
- 2-second timer

Right-click the following images and click "Open Image in New Tab", then zoom in.

All jpegs right from the my Pentax K-50.

F5.6, 1 second exposure:

Senior Member

Registered: November, 2018
Posts: 133

2 users found this helpful
Lens Review Date: October 3, 2019 I can recommend this lens: Yes | Price: N/A | Rating: N/A 


Loyal Site Supporter

Registered: November, 2012
Location: Jasper, AR
Posts: 3,325

2 users found this helpful
Lens Review Date: September 3, 2019 I can recommend this lens: Yes | Price: N/A | Rating: 10 

Pros: small, fast, sharp, easy to use, inexpensive, ubiquitous
Cons: a bit soft wide open... not necessarily a negative, challenge for MF
Sharpness: 10    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 10    Camera Used: K-1 mII   

The Pentax M50 f1.4 is the fastest 50mm in their M series, which ran during the late 70s and early 80s. The M was probably supposed to stand for "miniature" since most of the Ms are small compared to contemporaries, and very very small compared to their modern equivalents. This particular lens was one of the first manual focus lenses I bought, and I intended it for use on adapters with the Sony NEX APSC system. These are inexpensive lenses and are also fairly ubiquitous. Pentax makes a faster f1.2 50mm lens, but not in the M series.

The lens handles excellently, with a rubberized focus ring and an aperture ring without an A setting. The lens has a 49mm filter ring like many other M and A lenses and weighs 235g (0.5#).

50mm is a "normal" focal length, and were sold with 35mm film cameras as a complete kit back in the day. That's one reason there are so many of them, another is that the focal length is generally popular.

Manual focusing can be a challenge, since the depth of field is narrow and details in the viewfinder can be quite small. Split focus screens were useful on film cameras, but they don't put them in digital cameras anymore since they interfere with automatic metering. Thankfully, the K-1 and K-1 mII has an articulating rear LCD screen that can be used as a live viewfinder and can magnify the image, ensuring precise focus when needed.

The photo above is an example of the narrow depth of field you can get with this shot, taken wide open. This was in mid-day sun, bright sun, intense heat, but thankfully over the course of the day, not long lasting. Anyway, at f/1.4, and at such a close focus distance, all four of the heads could not fit inside the focus plane.

Balancing the shutter speed versus aperture here, in order to get both a shallow depth of field and the blurring effect of rising bubbles. I think the aperture here was f/2.8, and whatever was on TV complemented the color of the wine nicely I thought. This was manual focus (of course) done with the rear EVF. Usually slow shutter speeds require a tripod, but here I rested the camera on my knee and a technique that involves slow breathing and careful motion on the shutter button.

BIRD scooters can be rented for a quick runabout downtown Kansas City. Most of the time they get parked out of the way on the sidewalk, where they wait for a new passenger or the charging truck. Sometimes, BIRD pilots park their chariots in the wrong place, where tragedy can befall them. The cause of this carnage is unknown, but presumed to be death by automobile.
I chose black and white for this one, since the colors were drab anyway, and since it conveys the somber mood of the scene.

Thanks for looking!
Site Supporter

Registered: June, 2013
Location: Utrecht
Posts: 59

1 user found this helpful
Lens Review Date: August 6, 2019 I can recommend this lens: Yes | Price: N/A | Rating: 10 

Pros: Produces briljant pictures, 1.4 is a bonus.
Cons: Dreamy wide open, but maybe that's positive too...
Sharpness: 9    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 10    Camera Used: From K2 to K1ii   

Together with my M2.0/85 this is my most adorable piece of glass. A compact heavy brick of aluminum with lots of nicely coated bright elements in it. I bought it new as a kit lens with my ME in 1978. I always shot wonderful pictures with it, much more punchier than my friends who used standard zooms that times. At F1.4 it is dreamy and difficult to focus spot on on film cameras. For one reason images spot on in the split screen finder were often not spot on on the film. F2.0-2.8 was ideal for contrasty object isolation, between F4-F5.6 it was sharp as hell. And it still is on 36MP Full Frame. I always use the original hood to avoid the front lens catches direct sunlight from beside, that results in flair. Great build quality, after 40 years it still works like new.

See also

Wide open on K1ii:

F2.0 or 2.8 on film (1995), scanned on Coolscan V:

Original test report 1978:

New Member

Registered: May, 2014
Posts: 7

1 user found this helpful
Lens Review Date: May 19, 2019 I can recommend this lens: Yes | Price: $40.00 | Rating: 9 

Pros: Sharp, great colors rendering, superb reversed for macro
Cons: Fringing
Sharpness: 8    Aberrations: 8    Bokeh: 9    Handling: 9    Value: 9    Camera Used: K1   

I bought it several years ago, unfortunately comes with severe fungus issue.
I dismantled it and cleaned deeply with oxigenated water 50% in every parts.
Today, I'm proud to use it. It's the best lens I have. I love it.

this is reversed in macro, natural light f/16 1/500sec ISO 200 free handled:
Bee on orange flower by Salvo Signorello, su Flickr
Senior Member

Registered: May, 2011
Location: Malmö, Sweden
Posts: 126
Lens Review Date: July 29, 2018 I can recommend this lens: Yes | Price: $80.00 | Rating: 9 

Pros: Sharpness, bokeh, value
Sharpness: 9    Aberrations: 8    Bokeh: 9    Handling: 10    Value: 10    Camera Used: K-5, K-x   

Really good lens and extraordinary value for money. Very sharp, little softer wide open of course but that's to be expected and good for portraits. Haven't noticed much aberrations except some slight barrel distortion. No vignetting om APS-C that i can notice. A little weak in backlit conditions but that's rather common in older lenses. For the price it's absolutely excellent!
Veteran Member

Registered: July, 2014
Location: Nagoya
Posts: 577
Lens Review Date: January 27, 2017 I can recommend this lens: Yes | Price: $50.00 | Rating: 9 

Pros: Image quality, build quality
Cons: Fringing

There's little that remains to be said about this lens. Sharp (my copy is even sharp wide open as long as you nail focus), very pleasant rendering, great bokeh, lovely M series handling and great value.
On the negative side, you have to contend with a fair amount of colour fringing especially at wider apertures, and this is true of all Pentax 50/1.4s up to and including the FA. It's also a little heavier than its f1.7 and f2 counterparts.

It's a very capable lens, although in my opinion the manual focus 50 to have remains the A50/1.7 - easier metering, lighter, startlingly sharp and very little fringing.

Registered: April, 2009
Location: Madrid, Spain
Posts: 7,207

4 users found this helpful
Lens Review Date: September 26, 2016 I can recommend this lens: Yes | Price: $120.00 | Rating: 9 

Pros: Build quality, image quality stopped down, compact
Cons: Soft wide open, expensive
Sharpness: 9    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 8    Camera Used: K200D, K3, various film SLRs   

This lens is my go-to 50/1.4 due to it's build quality, compactness and optics. I use it on digital and also on film, where I find the feel of this lens is really ideal with a 35mm SLR.

I have owned the M, K and (seven element) SMC Tak 50/1.4s and they all perform very similarly. In terms of sharpness they are all soft wide open (not really usable in my opinion), acceptable by f/2.0 or f/2.4 and great at f/2.8 and beyond. In other optical qualities, colour and contrast from the M 50mm are really good, though contrast is unsurprisingly lacking at f/1.4 and maybe f/2. Bokeh is generally smooth and I've never had any problems with flare. I find this lens gives a rendering very similar to much more modern lenses rather than the less contrasty, less saturated "vintage" look that many old lenses give.

Build quality is great as with all the M series lenses and handling is superb - this lens is a pleasure to use. Focus is very smooth and the aperture ring clicks nicely.

Recently I've acquired an Auto Revuenon 50mm f/1.4 and discovered that it's optically slightly better than the M series lens, being slightly sharper wide open. It's just as compact and well built, has the same 49mm filter ring, it was also half the price. That lens could conceivably one day push me to sell the M series one, or at least to replace it as my go-to 50/1.4.

As all Pentax 50mm f/1.4 lenses are soft wide open, in terms of sharpness it's really impossible to justify having one instead of (or in addition to) a 50/1.7, which is smaller, lighter, just as well built, much cheaper, just as sharp at f/2.8 and considerably sharper wide open. The f/1.4 has eight aperture rings rather than six, so bokeh is smoother, but beyond that there really isn't much difference optically. In the end, if you really want an f/1.4 lens (as many people, myself included, do) then nothing else will do, but the sheer speed adds a lot of weight and cost without adding anything optically. The only real advantage in the optics are the extra aperture leaves for smoother bokeh. I find with all the 50mm lenses that I very rarely use them at less than f/2.8, where the combination of sharpness and ability to isolate a subject are ideal.

I'm not about to get rid of my copy of this as it's very good optically, though recently the Auto Revuenon has been getting more use, but it's mainly because I'm far too much of a gear freak to not have at least one really good f/1.4 lens.

Overall, this is a really nice lens and I rate it highly, though it's not good value for the reasons stated above.

Some sample images on digital.

Wide open at f/1.4:

by Jonathan MacDonald, on Flickr

At f/2.8:

by Jonathan MacDonald, on Flickr

by Jonathan MacDonald, on Flickr

Unknown aperture:

by Jonathan MacDonald, on Flickr

by Jonathan MacDonald, on Flickr
Forum Member

Registered: December, 2015
Posts: 50
Lens Review Date: September 24, 2016 I can recommend this lens: Yes | Price: $30.00 | Rating: 9 

Pros: Contrast, sharp, usable wide open
Cons: Soft in the corners
Sharpness: 10    Aberrations: 9    Bokeh: 10    Handling: 8    Value: 10    Camera Used: Pentax K-50   

Great 50mm lens, with 1.4 you can make wonderful pictures. However, to film, it's barely usable : at 1.4, you have no less than 2 centimeters of focus (the bokeh gets astonishing, but the slightest movement if you film someone will make it go blur)
Naturally, the contrast is great, and the colors are just right.

On the down sides, there are the corners : some vignetting appears wide open, and it is little soft while in the middle it's razor sharp.

I also set 8 to the handling, not knowing what it can do when perfect, as my copy has somewhat of a "hard" focusing ring, I suspect it was dropped or bent or something.

I would recommend this for photography (I used it only on K50, so digital), it's a little heavier than the 50mm F1.7 or F2.0, but it is as sharp and it's bokehlicious. Anyway, it remains a "dreamy" lens, even if you focus right, because at 1.4, a face on the side can't be in focus all the way.
New Member

Registered: July, 2016
Posts: 4

1 user found this helpful
Lens Review Date: August 7, 2016 I can recommend this lens: Yes | Price: $80.00 | Rating: 9 

Pros: bokeh, contrast, colours, size, weight, cenral sharpness from f2
Cons: soft wide open, corners soft until f4
Sharpness: 8    Aberrations: 9    Bokeh: 10    Handling: 9    Value: 9    Camera Used: Sony A7s, Sony a6000   

Good lens overall, excepts maybe for corner sharpness.

Great bokeh, contrast and colours. Good flare resistance. Handles well on small morrorless cameras even with an adapter.

For image samples check out my review of this lens at
Add Review of SMC Pentax-M 50mm F1.4

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