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SMC Pentax-M 50mm F1.4 Review RSS Feed

SMC Pentax-M 50mm F1.4

Reviews Views Date of last review
111 636,972 Mon September 12, 2022
Recommended By Average Price Average User Rating
99% of reviewers $75.95 9.29
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
Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 1-15 of 111
New Member

Registered: November, 2013
Posts: 14
Review Date: September 12, 2022 Recommended | Price: $100.00 | Rating: 10 

Pros: very sharp lens
Cons: very few CAs wide open
Sharpness: 10    Aberrations: 9    Bokeh: 10    Handling: 9    Value: 10    Camera Used: pentax k-5 k-x k200 k-s1 Fuji x-t100 x-e1   

Excellent lens

++ razor sharp, even with 1.7x AF converter

85 LP/mm = 170 black and white lines per mm between f2.8 and f 5.6 with the above mentioned converter. This is a professional value.

++ CAs are absolutely eliminated with APS-C sensors and converter

++ excellent color rendition

++ nice bokeh

best results with APS-C sensor and high resolution (20-24 MP)

9.5 points for APS-C ((for 24x36mm 8.5 points because of CAs in the corners wide open))
New Member

Registered: August, 2021
Location: Montréal, QC
Posts: 23

1 user found this helpful
Review Date: September 10, 2021 Recommended | Price: $25.00 | Rating: 10 

Pros: Sharpness stopped down, nice bokeh, delicate portraits wide open, rendering, contrast, very high quality, superb design, very compact and light
Cons: None
Sharpness: 9    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 10    Camera Used: MX, K-1 II   

Between the AF-S 50mm 1.4G, the Planar 1,4/50 ZF.2 and the SMC Pentax-M 50mm 1.4, would say the Pentax isn't the sharpest but is good and renders the best images in my opinion.

I bought the MX and the M50 1.4 lens for slightly less than $50, so I split the amount in two.

When introduced was to match the more stylish ME and MX smaller and lighter bodies. The design is beautiful and is of very high quality construction. By modern standards it's a pancake lens.

It has dreamy look wide open, acceptably sharp if not pixel peeping, and very nice bokeh. When stopped down it's a very sharp lens and without aberrations. SMC coatings are first rate, contrast is great and flare minimal.

The A version would perhaps be more practical on the K-1 II. On the Pentax MX it's perfect.
New Member

Registered: March, 2019
Posts: 2

1 user found this helpful
Review Date: August 27, 2021 Recommended | Price: $80.00 | Rating: 9 

Pros: size, weight, build quality, focus smoothness, handling
Cons: I have the SMC m 50mm f1.7
Sharpness: 8    Aberrations: 9    Bokeh: 9    Handling: 9    Value: 9    Camera Used: Pentax MX and me super, Sony a7 and a6000   

I craved this lens for a long, long time. I bid on auctions unsuccessfully on numerous occasions. I finally found the copy I have now for a fair price and jumped at it.
A year later and I can honestly say I barely use it. In fact I've only used it a handful of times. The reason being that I have its little brother, the SMC Pentax m 50mm f1.7. If I am shooting film using either the MX or me super, the 50 1.7 gets the nod. If I am shooting the a6000, the 50 1.7 again gets the nod. Despite being barely any slower, it is noticeably lighter and slightly smaller. For me, if I am using a small camera, I want a small lens. The 50 1.4 is small but the 1.7 trumps it. So, will I keep it? Honestly, I am not sure. So, if you have the 50 1.7 lens, my personal opinion is that you don't need the extra speed. If on the other hand you don't have the 50 1.7, grab it. As you can see above, I rate this lens very highly indeed. Its just that I prefer its little brother.
New Member

Registered: April, 2021
Posts: 16
Review Date: April 26, 2021 Recommended | Rating: 7 

Pros: Sharp at f5.6 right across, except very tip of corners
Cons: Tip of corner softness never completely resolves (on full frame)
Sharpness: 7    Aberrations: 6    Bokeh: 9    Handling: 10    Value: 9   

I have had this lens since 1976 (with a K2). I have used it a lot on my K3 and have just rigorously tested it on my K1.

I always start by checking the lens focuses correctly at infinity. When I first checked the M 50 on my K3 I found it was not able to focus on infinity at the end stop. I had the same issue with my 30 2.8. Adjusting the focus end stop is straightforward on M (and so called K) lenses ( and now it focuses perfectly at infinity. There is no focus shift across apertures.

My review is based on taking the same landscape with buildings detail and winter trees in the distance in the corners of the frame on a full frame K1, from f1.4 to f11 focused at infinity. Observations were made in Photoshop at 100%.

I made the general observation at all apertures that when focused at far distance in the centre of the frame, the focal plane ('field') comes forwards significantly towards the borders. I would expect the focal plane to be equidistant from the camera across the frame and therefore slightly curved, but the focus in the borders is far forward of an equidistant curve. I researched this further and the phenomenon is called Petzval Curvature, where the focal plane ('field curvature') is paraboloidal and worse at open apertures. Some lens tests do provide a 'field map' of edge sharpness deterioration and I now understand this is attributable, at least in part, to this effect. I understand that is it possible to mitigate this in lens design and I haven't noticed it particularly on my other lenses (although I have only recently upgraded to full frame) but it is clearly significant in this lens on a K1. So when I say soft at the border I mean soft and forward focused at the border.

f1.4 acceptably sharp only in the very centre, with softness and 'forward focusing' increasing progressively towards the borders.
f2 acceptably sharp within the centre third.
f2.8 sharp up to half way towards the border.
f4 sharp to the 10% of the border, corners soft.
f5.6 sharpest overall, borders acceptable but still soft in the corners.
F6.7 corners improving but overall starting to soften as diffraction begins to take overtake.
Stopping down further, this trend continues but very tips of corners never completely resolve even at f11; because of this I can't give more than 7 for sharpness on full frame. On the K3 images are sharp corner to corner from f4.

Colour and contrast and CA. Aberrations as explained and hence scored 7 (but wouldn't be visible on an APS-C, e.g. K3).

I have just acquired an F 50mm f1.7 and undertaken the same testing procedure. Conclusion on full frame K1: very sharp corner to corner at F8; better lens overall with 9 for sharpness.
New Member

Registered: June, 2020
Posts: 11

4 users found this helpful
Review Date: October 1, 2020 Recommended | 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
Review Date: July 27, 2020 Recommended | 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

3 users found this helpful
Review Date: January 21, 2020 Recommended | 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.
Junior Member

Registered: December, 2019
Posts: 41

1 user found this helpful
Review Date: December 31, 2019 Recommended | 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)
Veteran Member

Registered: September, 2017
Location: Medellín
Posts: 1,322

1 user found this helpful
Review Date: December 23, 2019 Recommended | 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

1 user found this helpful
Review Date: November 5, 2019 Recommended | 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:


Registered: November, 2018
Posts: 517

4 users found this helpful
Review Date: October 3, 2019 Recommended | Rating: N/A 



Registered: November, 2012
Location: Ingelheim am Rhein, Germany
Posts: 5,779

3 users found this helpful
Review Date: September 3, 2019 Recommended | 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!
Senior Member

Registered: June, 2013
Location: Utrecht
Posts: 197

2 users found this helpful
Review Date: August 6, 2019 Recommended | 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

2 users found this helpful
Review Date: May 19, 2019 Recommended | 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

1 user found this helpful
Review Date: July 29, 2018 Recommended | 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!
Add Review of SMC Pentax-M 50mm F1.4

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