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SMC Pentax-A 50mm F1.2

Reviews Views Date of last review
29 227,813 Mon February 4, 2019
Recommended By Average Price Average User Rating
100% of reviewers $485.83 9.55
SMC Pentax-A 50mm F1.2

SMC Pentax-A 50mm F1.2
SMC Pentax-A 50mm F1.2
SMC Pentax-A 50mm F1.2
SMC Pentax-A 50mm F1.2
SMC Pentax-A 50mm F1.2
SMC Pentax-A 50mm F1.2

The SMC Pentax-A 50mm F1.2 is the fastest A-series 50mm lens variant, featuring the largest aperture available in the K-mount. While the standard version had a black barrel, it also came in a special-edition bundle with the LX 2000 with a barrel design resembling that of the current silver FA Limited lenses. The rare LX2000 bundle typically sells for $4000-5000 USD.

SMC Pentax-A 50mm F1.2
©, sharable with attribution
Image Format
Full-frame / 35mm film
Lens Mount
Pentax K
Aperture Ring
Yes (A setting)
Automatic, 9 blades
7 elements, 6 groups
Mount Variant
Check camera compatibility
Max. Aperture
Min. Aperture
Min. Focus
45 cm
Max. Magnification
Filter Size
52 mm
Internal Focus
Field of View (Diag. / Horiz.)

APS-C: 32 ° / 27 °
Full frame: 47 ° / 40 °
Various types
Hard case HB-90 (initially), soft case S70-70 (later)
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Diam x Length
65 x 49 mm
345 g
Production Years
1984 to 2004
Engraved Name
smc PENTAX-A 1:1.2 50mm
Product Code
User reviews
Sold without hood. Several hoods will fit such as PH-S52 (50mm) and PH-R52
A silver version "smc Pentax-A 1:1.2 50mm Special" was produced for the silver Pentax LX 2000. This version came with a matching metal screw-in hood.
Manual FocusAperture RingAutomatic ApertureFull-Frame SupportDiscontinued
Price History:

Add Review of SMC Pentax-A 50mm F1.2
Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 1-15 of 29
Senior Member

Registered: April, 2007
Location: Toronto/Victoria
Posts: 262
Lens Review Date: February 4, 2019 I can recommend this lens: Yes | Price: $400.00 | Rating: 9 

Pros: Relatively compact, great IQ, great build quality
Cons: A bit glowy wide open
Sharpness: 9    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 9    Camera Used: K100D, K-1   

Like most older fast 50mm lenses, the A50/1.2 has the usual key weakness of wide open IQ that is quite glowly when it is bright outside or for points of light. However, it improves very quickly and by F1.8-2.0 I'm very happy to use the lens anytime/anywhere unless more DOF is required. It might show a trace more red/blue CA than the slower 50mm lenses but you can do much worse.

It's heavier and larger than the traditional 50mm F1.4 lenses, but the filter diameter is just slightly more at 52mm vs the typical 49mm. The aperture has 9 blades.

My copy was basically new and obtained used for C$500 in 2009. It is an excellent lens overall and the size should be put in context of more contemporary lenses.
Site Supporter

Registered: September, 2015
Location: Berlin
Posts: 116
Lens Review Date: August 28, 2018 I can recommend this lens: Yes | Price: $450.00 | Rating: 10 

Pros: F1.2, IQ, sharpness, Bokeh
Cons: no autofocus

Not easy to get, but if you got it you will not miss it anymore.

The A Version of the Pentax 50mm F1.2 is a bit better then the K Version. I still have both of them and to my copies the A Version is sharper at F1.2

I love its Bokeh on Portrait or for detailed pictures.
Its sharp at 1.2 but razorsharp from F1.8-F9
On my Copy the sweet spot is F9.
Perfect for chooting stars using F1.8 at infinity (infinity marking is infinity !)
Ist Overall Image Quality is great. I use it for Portrait and landscape on K.3 and MZ-6

For me it is not a contra but a nice to have.
A autofocus 50mm F1.2 of Pentax would be nice. Cause handling the F1.2 is not as easy using Manual Focus. Depending on your distance you sometimes have 2-3 cm of sharpness.

Overall itīs a 10 because of sharpness and bokeh. Thats what you need with a F1.2 lens

Senior Member

Registered: May, 2014
Location: Galway - Ireland
Posts: 213

2 users found this helpful
Lens Review Date: September 13, 2016 I can recommend this lens: Yes | Price: $450.00 | Rating: 10 

Pros: Sharpness, Very specific look
Cons: Cost (?)
Sharpness: 10    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 8    Camera Used: K-1, K-3   

I actually waited for my K-1 to arrive to make both a FF and an APS-C review of the lens. I got my copy from a forum member, slightly bumped (but the optics is perfect) which explains the lower than average price for this lens.

Basically the question is mainly 'is it worth the money ?'. We all know that there are plenty of 50mm around, and some of them are outstanding for a much lower price. Then is it worth adding this price difference for the extra stop or half stop of light ? Well even if you will get more light it makes no sense to buy this lens only for the extra light. Nowadays cameras are good low light performers and the difference between a f/1.4 and a f/1.2 is negligible in terms of light. So why are you paying for ? 1) the crazy look you get at f/1.2-1.4 and 2) the extra sharpness you get at f/1.4-f/2 apertures. If you mainly shoot at f/2.8 and above, get a SMC 50mm f/1.4.

Great glass, built like a tank but still quite light. The focusing ring is perfect (maybe a bit less smooth than some SMC M lenses but still great), the aperture ring is great too.

To focus with this lens is not that easy wide open. If you plan to use it wide open, be sure that it is only in a controlled environment where you can take your time. In 'field' conditions f/2 and above gives a very high hit rate.


This lens is quite sharp. On the 24MPx K-3 the sharpness is good starting at f/1.6 and impressing at f/2 and above. The f/1.2 is a bit soft and glowy.
The result is a bit soft at f/1.2, but starting at f/1.4 is great. f/1.8 and above are all super sharp.

Bokeh is great and soft as you can expect. The results at f/1.2 are very impressive. There is probably a bit of spherical aberration at f/1.2 that makes some edges a bit bubble like, but overall it is a bokeh monster.

Not flawless wide open (purple fringing), gone by f/2.

Surprisingly good. Compared with the SMC M 50mm f/1.4 there is a real improvement.

Slightly warm (I love it). I noticed that at f/1.2 the color is slightly shifted to the pink. Great colors overall.

Nothing to be noticed.

A bit strong on FF wide open, very decent on APSC. Starting at f/1.8 the problem is essentially solved


I must admit that I have not tried the 55mm f/1.4 star lens yet (will update when I manage to try this one) and this would be a nice comparison. Otherwise,

>50mm f/1.7 SMC M
Tried on APSC : Great lens overall, specially good starting at f/2.8. Super light and cheap. Optically, it does not catch up with the 50mm f/1.2 on wide apertures.

>50mm f/1.4 SMC M
Tried on APSC : It was my main lens for a very long time and one of my first ones. It's overall a very good lens and I really loved it. It competes easily with most modern 50mm lenses. I consider it to be top sharp from f/2.4, but I often used it at f/2. The flare resistance of this lens is unfortunately quite bad. If you want a good quality for money ratio go for this lens !

>50mm f/1.4G nikkor
This is supposed to be Nikon modern standard for pros. I would say that the image quality is not as good (not as sharp and with fringing) as the Pentax at f/1.4. I compared D800E+50 vs K-1+50 which seems fair to me and some Nikon users tried also my K-1+50 for a few days and conclude the same thing.

If you love portrait or are in love with good optics, buy this lens without a regret. It's all good, even better on FF. It's worth every penny because it is not just a 50mm. It's premium optics with an outstanding combination of sharpness and bokeh smoothness.

APSC (f/1.8) (f/1.3)

FF (f/1.2) (f/1.6) (f/1.6)

Registered: November, 2009
Location: Brisbane, Australia
Posts: 3,642
Lens Review Date: April 8, 2016 I can recommend this lens: Yes | Price: $550.00 | Rating: 9 

Pros: Fast, sturdy, Automatic aperture
Cons: Price
Sharpness: 10    Aberrations: 9    Bokeh: 8    Handling: 10    Value: 8    Camera Used: K-3   

The A50mm f1.2 is my 3rd fast fifty lens. I have a Voigtlander Nokton 58mm f1.4, and Pentax FA50mm f1.7. I bought the A50mm f1.2 to dare to try .. [LBA]. My interest was the large aperture, i.e. my fatest lens so far. There is no doubt that the lens is fast. Its construction is sturdy and sold. I love the automatic aperture option. The lens works well with Liveview and focus peaking.
If I compare the A50mm f1.2 with the VL58mm f1.4 and FA50mm f1.7, the VL58mm is a clear winner: better colour rendition, as sharp, almost as fast. The A50mm f1.2 is my number 2 fast fifty.
Overall this is a special lens, particularly valuable when you need to work in low to very low light. I believe that it is not for everyone, but I would recommend it for anyone who dares to be different....
New Member

Registered: May, 2014
Location: Fraser Coast
Posts: 9

2 users found this helpful
Lens Review Date: October 26, 2014 I can recommend this lens: Yes | Price: N/A | Rating: 10 

Pros: Creamy Bokeh, Sharpness, Colour and Handling.
Cons: Nil

The bokeh, sharpness and handling on the A is outstanding.I was very lucky as this lens come with my K10D which I bought off eBay Australia for the tidy sum of A$123.50. Didn't realise what I had until I started researching on PF. The A 50 1.2 is a great performer in all aspects.

Senior Member

Registered: March, 2010
Location: Svealand
Posts: 172

1 user found this helpful
Lens Review Date: June 23, 2013 I can recommend this lens: Yes | Price: $730.00 | Rating: 10 

Pros: bokeh, f1.2, sharp, build quality
Cons: Expensive
Sharpness: 10    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 9    Camera Used: Pentax K-5   

Great lens, nice bokeh.

Only negativ aspect is that I couldn't find it for a better price. But as it's a lens that's build to last and that it was in mint conditon i guess the price is rather ok. Especially as it's so hard to find where I live that I had to buy it from eBay Japan.
Forum Member

Registered: August, 2010
Location: Edinburgh
Posts: 91

3 users found this helpful
Lens Review Date: May 1, 2013 I can recommend this lens: Yes | Price: $545.00 | Rating: 9 

Pros: unique, sharp, wide maximum aperture
Cons: bulky, expensive
Sharpness: 9    Aberrations: 7    Bokeh: 10    Handling: 9    Value: 7    Camera Used: k-5, Canon 7D   

This is a reasonably rare lens with a high second hand value, and the largest maximum aperture among all Pentax lenses from all lens series.

Image quality
At f1.2 the lens is soft, low contrast, low detail, purple fringing - Ďdreamyí Ė I donít particularly like that this effect in the majority of circumstances but it is unique and sometimes it works very well. For example, flattering portrait photography, particularly in black and white with low contrast lighting.

At f1.4 to f2
Big jump in sharpness and contrast. Importantly, itís sharper than the A and M 50mm f1.4 for these apertures, which youíd hope since this is a bulkier and more expensive lens.

Above f2
Wonderfully sharp, excellent soft background blur.

The image quality from this lens is very good, though not a huge leap ahead in terms of image quality from the other A and M 50mm lenses I have used (A 1.7, M 1.7, and M 1.4) apart from the lovely bokeh, made softer by the 9 blade aperture. For portraits and reasonably close shooting at near the maximum aperture, this is the king.

Colours are vibrant and consistent with the look of other pentax lenses of this era.

This is a solid, wonderfully built lens, like the best in the A and M series. Itís reasonably small compared to most lenses (including modern lenses and lenses from other manufacturers) but big compared to its 50mm Pentax peers. Itís also a big chunky piece of glass, and weighty.

Focus throw is pretty huge for fine focusing, which suits me as I also use it for filmmaking with manual focus, but for fast focus changes it feels like an awfully long way to turn it.

Important points
Chromatic aberrations on this lens are pretty high in my opinion. Youíll get used to this and can learn how to shoot to minimise it, but itís a fairly ugly purple slash down highlight edges.

A lot of similar Pentax primes from this era have 49mm threads (including all of the other 50mm lenses from the A and M series), so for me itís a slight pity that this is 52mm thread. It just makes it a little less handy for interchanging filters and lens caps.

Bokeh is wonderful. This lens is designed for great background blur, with a rounded 9 blade aperture and an optical design that brings this smoothness out. Nothing else compares to it at any aperture.

This lens has a big front element which invites flare and reduced contrast. Use a lens hood and a lot of this disappears, so I always do.

Is this lens worth the cost?
When I bought my lens it was 3 times more expensive than the Pentax-A 50mm f1.4, which is itself a great lens. Thatís a lot of extra cost to justify.

Of course, the 50mm 1.2 has that special look when used at f1.2, and the Ďdefectsí like low contrast and chromatic aberrations are an important part of that. If you donít like this look or donít intend to often shoot with this wide open, itís probably not worth buying this over one of Pentaxís other excellent old 50mm lenses.

Also, if you have that sort of money to spend and want the best 50mm lens you can get, consider the more modern Pentax FA 50mm f1.4, which I think handles aberrations much better and has autofocus. The background is less beautifully rendered though.

In conclusion, it's a wonderfully made lens capable of uniquely dreamy shots or tack sharpness with beautiful background blur and a few aberrations which can sometimes be very apparent in real world circumstances.

Sample pictures and video
A picture at f1.7 showing the nice background blur
This short film was all shot on the lens at f1.4 to f2. Apart from the two close ups of the glass which were shot on a pentax-A 100mm f4 macro.
Using the lens in reversed position at f8 - very sharp, nice colours
Senior Member

Registered: January, 2011
Posts: 258

2 users found this helpful
Lens Review Date: April 14, 2013 I can recommend this lens: Yes | Price: $300.00 | Rating: 9 

Pros: Good build quality for an A lens, sharp, great color and contrast for a wide aperture one, 9 blade diaphragm, easier to focus than 1.4 models
Cons: Nervous bokeh at 1.2 but still usable, blue fringing at 1.2(but still good for that old lens), CAs are like in FA 50 1.4, not the sharpest one closed down, rare and pricy
Sharpness: 9    Aberrations: 8    Bokeh: 10    Handling: 10    Value: 6    Camera Used: K30   

First I'll show my first shots with it in the moment of the deal. This is what made me bought it.




Perhaps it is the sharpest lens(at wider apertures) Pentax was selling for all the times. I loved it, It is made in pentax traditions with very small size and the huge front element(about 50mm wide) have nowhere to hide, but I started shooting without hood and guess what the FA 50 1.4, SMC Tak 50 1.4 and M 50 1.4 are much worse than that. This one can handle light better, I'm going to buy it a proper hood and probably things will go even better .
I'm having problems to work with it on my K30 with LV because on A setting the camera close the aperture(impossible to focus) and on manually set 1.2 the mettering works wrong(still don't know why). I hope that I will solve that soon.
Soon I will add more photos so stay tooned .

I will add link here to my head to head comparison with FA 50 1.4 and Zenitar 50 1.7
Veteran Member

Registered: January, 2010
Location: Mumbai, India
Posts: 399
Lens Review Date: January 22, 2013 I can recommend this lens: Yes | Price: $80.00 | Rating: 10 

Pros: Colour,ease of focus,OOF rendering, f/1.2!
Cons: None
Sharpness: 10    Aberrations: 8    Bokeh: 10    Handling: 10    Value: 10    Camera Used: K-x   

Yes, I paid 80USD, and yes, it is an f/1.2 lens. Lovely bokeh, colour rendition and handling. Very easy to focus on the stock K-x screen.
Site Supporter

Registered: November, 2010
Location: California
Posts: 2,223

4 users found this helpful
Lens Review Date: June 24, 2012 I can recommend this lens: Yes | Price: $785.00 | Rating: 10 

Pros: An all around lens, the only one you need.
Cons: Steep learning curve due to the thin d.o.f. at f/1.2
Sharpness: 10    Aberrations: 10    Bokeh: 10    Handling: 10    Value: 10    Camera Used: Pentax K5   

I just got this lens. Photos to follow after I develop them.

Here are the first photos at f/1.2

Pentax-A_50mm_f1.2-HojaDeParra1-1 by Palenquero, on Flickr

Pentax-A_50mm_f1.2-HojaDeParra2-1 by Palenquero, on Flickr

Here are some more:

Pentax-A-50mmf1.2-AFiddlerontheroof6-1 by Palenquero, on Flickr

Pentax-A-50mmf1.2-Buda2-1 by Palenquero, on Flickr

Pentax-A-50mmf1.2-Anturio-1 by Palenquero, on Flickr

Backstage by Palenquero, on Flickr

Pentax-A-50mmf1.2@f1.2-Flower&Bokeh-1 by Palenquero, on Flickr

Pentax-A-50mmf1.2@f2-Whesteria-1 by Palenquero, on Flickr

Pentax-a-50mmf1.2@f1.2-Leaves2-1 by Palenquero, on Flickr

Pentax-a-50mmf1.2@f1.2-deal-1 by Palenquero, on Flickr

Pentax-a-50mmf1.2@f1.2-deal2-1 by Palenquero, on Flickr

Update: Dec. 20, 2014:

I sold this lens few months ago, I kept the Revuenon 55/1.2, which is very sharp and has slightly higher depth of field. However, I bought the lens again (two copies) last week, because I really missed it. I wanted to have two copies to compare if there were differences between copies, but no, they are both really nice. So, I am keeping my Pentax-A 50/1.2, and may sell the other. Once thing I learned after having owned Leica lenses on Leica cameras is to focus manually really well. The depth of fiel increases with the distance the subject is from the sensor. So, if you try to shoot close objects, be prepared for a very narrow depth of field. At about 3 feet, I am able to focus on a persons eyes perfectly and have them sharp with this lens. Just an advice to avoid frustration. This is true for any lens. Here are some photos:

Pentax-A 50mm f1.2 @ f1.2 - Cacti at Laguna-1 by Palenquero, on Flickr

Pentax-A 50mm f1.2 - Palm Trunks at Laguna-1 by Palenquero, on Flickr

Pentax-A 50mm f1.2 - Palm Trees at Laguna-1 by Palenquero, on Flickr

x21mmf3.2-Laguna-10-1 by Palenquero, on Flickr

Update January 17, 2015:

I think I am getting the hang of this beauty, what a lens:

Pentax-A50-1.2-Shingha1-1 by Palenquero, on Flickr
New Member

Registered: June, 2012
Posts: 4
Lens Review Date: June 19, 2012 I can recommend this lens: Yes | Price: N/A | Rating: 8 

Pros: Colours, Sharpness, Bokeh!!!
Cons: very shallow depth of field when stopped down but thats to be expected
Sharpness: 9    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 8    Camera Used: K5   

Would be the perfect lens with autofocus!
Inactive Account

Registered: April, 2009
Location: New York
Posts: 2

1 user found this helpful
Lens Review Date: November 1, 2011 I can recommend this lens: Yes | Price: $585.00 | Rating: 10 

Pros: Small and light, Sharp with nice bokeh!
Cons: None
Sharpness: 10    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 10   

Very sharp on Canon full frame and K-5 body. Sharper than my Hexanon 57 1.2, more contrasty wide open
and no visible difference in color rendering. Very easy focusing on K-5. Amazing lens.
Veteran Member

Registered: December, 2010
Location: Dallas, TX
Posts: 409
Lens Review Date: March 24, 2011 I can recommend this lens: Yes | Price: $560.00 | Rating: 10 

Pros: bokeh, colors, sharpness stopped down
Cons: large, price, very shallow DOF at 1.2

I've had this lens for a few months, and I have yet to be able to master it. It will be years until I ever do. The shallow DOF at 1.2 makes it very hard to nail the focus, especially for a beginner like me. My Kx tends to miss the focus in lower light situations, so I rely on feel and the viewfinder. However, when a picture does come through, the colors and bokeh make it all worth it. RXrenesis's picture above is a great example of the smooth, pastel-like colors this lens puts out at 1.2. However, stop it down and you'll get back the normal sharp and vivid colors of the other 50s.

Size and price aren't really cons. It's not really possible to produce a cheap and small 1.2 lens. The price really is justifiable if one wants to shoot at 1.2 since there aren't too many alternatives available. Even those like the K1.2, cosina, etc, have started to fetch a few hundred dollars!
Veteran Member

Registered: January, 2011
Location: Orlando, FL (USA)
Posts: 523

3 users found this helpful
Lens Review Date: March 10, 2011 I can recommend this lens: Yes | Price: $500.00 | Rating: 10 

Pros: f/1.2, manual focus ring is smooth, dampened, and has a long throw for the razor thin DoF.
Cons: Split prism or focus bracketing is required at wide apertures
Sharpness: 9    Aberrations: 7    Bokeh: 10    Handling: 10    Value: 9   

This lens is a tiny tank, built to destroy your preconceived notions of depth of field and suck up all the light it can find!

The one behavior that I hear controversy about is the apparent softness wide open:

(click image for larger sizes)

Now, if you look closely you will notice that it's not blurry but rather it lacks contrast. This is most visible in areas that transition abruptly from highlight to shadow (the towers of the bridge show this prominently).

Quite frankly I enjoy the way this behavior renders the scene so this lens is definitely a keeper!

Edit: Since I didn't include this last time (and it's one of the main draws of f/1.2), Here's some bokeh, at f/1.2 of course:

(click image for larger sizes)

(click image for larger sizes)
Inactive Account

Registered: June, 2009
Location: Berlin
Posts: 103
Lens Review Date: November 8, 2010 I can recommend this lens: Yes | Price: $400.00 | Rating: 10 

Pros: Great image quality, great build
Cons: -
Sharpness: 10    Aberrations: 10    Bokeh: 10    Handling: 10    Value: 9    Camera Used: K5, K20   

Update from July 2014:
I have to reevaluate this lens.
It is fantastic in all regards

When writing my OLD review (see below) I had problems with reflections, but this turned out to be caused by a low quality protective filter.

My OLD review from November 2010:
This is a great lens when stopped down.
I got it to use it wide open, where reflections appear as soon as a bright object is in the picture.
Wide open I therefore prefer my SMC A 50mm f1,4.
Add Review of SMC Pentax-A 50mm F1.2

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