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SMC Pentax-M 50mm F1.4

Reviews Views Date of last review
100 482,599 Tue September 3, 2019
Recommended By Average Price Average User Rating
99% of reviewers $77.11 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:

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Loyal Site Supporter

Registered: November, 2012
Location: Kansas City, MO or Jasper, AR
Posts: 2,779

1 user 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: 24

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: 5,793

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
Junior Member

Registered: December, 2015
Posts: 48
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
Site Supporter

Registered: April, 2015
Location: Lower Saxony
Posts: 141

3 users found this helpful
Lens Review Date: February 18, 2016 I can recommend this lens: Yes | Price: $40.00 | Rating: 9 

Pros: very sharp once stopped down, view finder brightness, color rendering
Sharpness: 10    Aberrations: 8    Bokeh: 10    Handling: 9    Value: 9    Camera Used: K-5 IIs; K-1   

uncared for a year i rediscovered this gem the last dark days...

down scaled offhanded out of camera jpgs, K-5 IIs, f/2.0:

(click into this second to enlarge original out of camera jpg)

crop reveals (golden) pearl necklaces also with K-5 IIs

down scaled out of camera jpg, K-1, f/2.0


p.s. @ wtigga: yours is the also great and with a radioactive Thorium glass rear element built SMC PENTAX K predecessor, ~ 1975-1977...
Inactive Account

Registered: December, 2015
Posts: 1
Lens Review Date: February 2, 2016 I can recommend this lens: Yes | Price: $55.00 | Rating: 10 

Pros: image rendering on film / 3d pop / wide open iq
Cons: none
Sharpness: 10    Aberrations: 10    Bokeh: 10    Handling: 10    Value: 10    Camera Used: Pentax LX   

Best 50mm i ever used - and i've used quite a lot of them. Had several Nikon 50s from old Ais version to the good old 50/1.4D or the pancake E-series 50 and also some late 50/1.8 and they all had there flaws optically AND none of them had the same great haptics and handling feel like this Pentax M 50/1.4! it's close to the high price rivals from the big brands with Z or L, but bigger of course.

beside the handling also the optical qualities stand out. maybe only slightly but still in a relevant manner. it's maybe not the most sharp or most contrasty 50 in scientific tests but the render of details, tones and the transition from sharp to bokeh are delicious. the images have this special something. the wide open look is a tad soft but it's great for 1.4 and there is still plenty of details (with a bit less microcontrast).

the benefit of this lens compared to other 50s is only nuances for sure but enough for me to deeply fall in love with this lens.
New Member

Registered: August, 2015
Posts: 1
Lens Review Date: August 17, 2015 I can recommend this lens: Yes | Price: $89.00 | Rating: 10 

Pros: Small & compact, sharp, easy to handle
Cons: None I could find
Sharpness: 10    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 10    Camera Used: Canon 70D   

I'm new to vintage lenses, and this is the first one I bought - and am very happy with it. Light weight, great bokeh at 1.4, very easy to handle.

Only con I can think of has nothing to do with the particular lens - I learned the hard way that the depth of field is so narrow at 1.4, sometimes just a few inches, that one has to be very precise at focusing (used a chipped PK-EOS adapter with a single focus point, which was very helpful, because camera beeps when focus is reached). The main challenge is when shooting more than one person - must remember to close shutter a bit, to get a deeper depth of field.
New Member

Registered: March, 2015
Location: Oklahoma
Posts: 16
Lens Review Date: May 13, 2015 I can recommend this lens: Yes | Price: $35.00 | Rating: 8 

Pros: solid construction, image quality
Cons: very soft wide, color fringing outside of focus plane
Sharpness: 8    Aberrations: 7    Bokeh: 10    Handling: 10    Value: 8    Camera Used: K-500   

Good lens at f4 and smaller. I am disappointed at wider apertures. Even though that gaping light catcher looks impressive, it is too soft for anything but "bokeh art". I seldom shoot for subjects with arty blur. I like the 3D look of subjects in focus against the soft background. So for me this lens has no real advantage over the M 50mm f2 or the smc Tak 55mm f1.8. But I got it on eBay along with a dandy K1000, Vivitar 283 flash, bag, antique 35mm film, and a no name 70-200mm zoom, all for $65. I figure I paid about $35 for this M 50mm f1.4.

Veteran Member

Registered: December, 2010
Location: SoCal
Posts: 515
Lens Review Date: March 15, 2015 I can recommend this lens: Yes | Price: $75.00 | Rating: 9 

Pros: Price, snooth focus ring, sharpness, rugged, size, weight
Cons: Not the best for moving subjects/lighting due to M lack of auto metering

It would only be better for me if it was an 'A' lens for auto metering and aperture control in the body as an option.
Very sharp, very smooth, long focus ring.
Bokeh is very nice for most images. Slight CA in outdoor (lighting is harsh in SoCal).
Junior Member

Registered: February, 2013
Location: China
Posts: 30

1 user found this helpful
Lens Review Date: March 12, 2015 I can recommend this lens: Yes | Price: $45.00 | Rating: 10 

Pros: Sturdy, Cheap, Nice Bokeh, Pentax
Cons: Purple fringes on 1.4
Sharpness: 8    Aberrations: 4    Bokeh: 9    Handling: 9    Value: 10    Camera Used: Pentax K-7   

Very nice lens for it's price. Nice to think that this piece of art was produced almost 30 years ago, and still fully functional.
Got one in Seoul for less then 50 bucks.

More picks of this lens on my blog.
New Member

Registered: November, 2013
Location: Baku
Posts: 24
Lens Review Date: January 15, 2015 I can recommend this lens: Yes | Price: $110.00 | Rating: 10 

Pros: Sharp!!!
Cons: can be some CA
Sharpness: 10    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 10    Camera Used: K-30   

I got my dSLR about a year ago with a DA 50mm f1.8. I was very happy - then I bought this lens and I was
ecstatic!!! It's just beautiful - this lens is so sharp.

I got the DA 50mm f1.8 very cheap as a deal when I bought the K-30 but- I very rarely use it now because I love this lens so much!!

It's manual - for me this is a massive plus because I started to understand what my camera can do.

It's prone to CA - but honeslty even the CA tends to be good looking!

For me it's a massive step up from the DA 1.8 in terms of picture quality and also as my first manual lens it's taught me so many things about DOF etc.

Coil by istanbulnorthend, on Flickr
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