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SMC Pentax-A 24-50mm F4 Review RSS Feed

SMC Pentax-A 24-50mm F4

Reviews Views Date of last review
18 149,338 Fri December 23, 2022
Recommended By Average Price Average User Rating
94% of reviewers $136.06 9.22
SMC Pentax-A 24-50mm F4

This lens is optically identical to the F-series autofocus version.

SMC Pentax-A 24-50mm F4
©, sharable with attribution
Image Format
Full-frame / 35mm film
Lens Mount
Pentax K
Aperture Ring
Yes (A setting)
Automatic, 8 blades
11 elements, 10 groups
Mount Variant
Check camera compatibility
Max. Aperture
Min. Aperture
Min. Focus
40 cm
Max. Magnification
Filter Size
58 mm
Internal Focus
Field of View (Diag. / Horiz.)

APS-C: 62-32 ° / 53-27 °
Full frame: 84-47 ° / 74-40 °
RH-B 60 mm
Hard case HB-120
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Diam x Length
64 x 68 mm
375 g
Production Years
1984 to 1989
Engraved Name
smc PENTAX-A ZOOM 1:4 24-50mm
Product Code
User reviews
Manual FocusAperture RingAutomatic ApertureFull-Frame SupportDiscontinued
Price History:

Add Review of SMC Pentax-A 24-50mm F4
Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 1-15 of 18
New Member

Registered: April, 2019
Posts: 5
Review Date: December 23, 2022 Recommended | Price: $120.00 | Rating: 9 

Pros: sharp, rugged, constant wide open f/4
Cons: no depth of field scale, not parfocal
Sharpness: 9    Aberrations: 9    Handling: 6    Value: 10    Camera Used: k100d, k200d, K-r, Z50, A5100   

this a great lens when it is properly focused. i have the k100d, the k200d and the K-r. i have had nothing but trouble with all three with the focus confirmation light. pretty good in bright sun lite but everything else marginal. the focusing screens leave much to be desired in trying to use them only. i thought i had a dud until i mounted it on a sony a5100 and was able to focus it properly. it is an outstanding walking around lens. excellent results on the nikon z50 also. i made a cheat sheet using a 50mm lens with a depth of field scale so i can take advantage of hyperfocal distances as the lens has none. another con is this sample is not parfocal. when i focus at 50 mm and zoom to 24 mm i have to refocus. luckily the K-r has [low res] live view but that mode is a battery drain. this is a lens that dovetails in nicely with mirrorless cameras. don't forget a collapsing lens hood.
New Member

Registered: September, 2020
Location: Derbyshire
Posts: 3
Review Date: August 21, 2021 Recommended | Rating: 9 

Pros: Sharp, easy to use and very well made indeed, well controlled distortion
Cons: f4 is a very slow
Sharpness: 9    Aberrations: 8    Bokeh: 7    Handling: 10    Value: 9    Camera Used: MX   

I used this lens with film only NOT digital.

I was lent this lens by a colleague for a month who was hoping that I would buy it.

I would have but being a student at the time, I did not have the £300 he wanted for it.

I've got a picture of London Bridge at night on Ilford FP4 film with the aperture wide open at 24mm. Sure, you've got blobs of light on the bridge as the lack of aperture means no control of spherical aberrations but that shot was blown up, mounted and hung on the wall of my sister in law's house for almost 20 years and still gets glowing praise.

The exposure BTW was pure guess work, taken on the B setting of an MX resting on a wall near the Thames.

Otherwise, this is very well built lens. Performance wise there is a bit of barrel distortion at the wide end and little bit of pincushion maybe at the long end bit is not really enough to put you off a good subject matter. It's a lot smaller than the Nikkor 25-50mm and lighter too but its still built like a tank.

I also got some nice colour shots with this lens - nice colour with plenty of detail. At the time I did not want to give it back.

These days it seems to go a lot cheaper. I'd buy one but the KX I have does not like really slow lenses and I am not getting any younger or better sight-wise. It does have a really good focussing distance scale though unlike many modern zooms.

If you get focus indication in your Pentax DSLRs, try one of these out. They are optically very competent lenses indeed.
Site Supporter

Registered: March, 2020
Location: New Jersey
Posts: 34
Review Date: May 18, 2021 Recommended | Price: $12.99 | Rating: 9 

Pros: Love the zoom range. Got it on my K-3 and it may become my walking around lens because of the wide angle to 50 coverage!
Cons: None so far but I just picked it up and have only shot a few test shots
Sharpness: 9    Aberrations: 8    Bokeh: 8    Handling: 10    Value: 10    Camera Used: K-3   

I just picked up this lens at a thrift shop for $12.99. After reading the reviews I’m thrilled with the buy! I’ve only made a few test shots so far but I’m pleased with the overall sharpness, and I love the 24 to 50mm range. And the clear focal length markings make it easy to set the K-3 which requires the focal input setting in manual mode. So far, so good. I can see it being an everyday lens due to the versatility, great Pentax color, and decent overall performance. And I can’t complain about the price!
New Member

Registered: July, 2015
Location: Melbourne Australia
Posts: 1

1 user found this helpful
Review Date: June 19, 2019 Recommended | Price: $180.00 | Rating: 10 

Pros: Hamdling , solid and smooth to operate Great to carry around
Cons: None
Sharpness: 8    Aberrations: 8    Bokeh: 8    Handling: 10    Value: 10   

I received this lens from Japan a few days ago. I find it just fantastic. i really don't have any idea about the finer points, like Edge sharpness or
wide open softness. Actually, I could not care about all this As long as the pictures it makes please me, everything is fine.I normally use my lenses at about f5.6, unless circumstances require otherwise.
What I look for in a picture is my liking factor. And this is really great with this lens. It is very easy to handle, it feels solid and well mad. and I like the smooth zooming and focusing action. I always use a lens hood on all my lenses.
New Member

Registered: October, 2013
Location: Texas
Posts: 17

1 user found this helpful
Review Date: October 13, 2018 Recommended | Price: $99.90 | Rating: 9 

Pros: Great all-around lens.
Cons: None
Sharpness: 9    Aberrations: 9    Bokeh: 8    Handling: 9    Value: 10    Camera Used: K-1 II   

I've only had this lens for about a week. But I'm pleasantly surprised at the image quality at all apertures. And it's so versatile. Image quality is equal to if not slightly better than my 28-105 DFA lens. Currently this SMC Pentax-A Zoom 24-50 F4 will get lots of time on my new K-1 II.

New Member

Registered: October, 2015
Posts: 2
Review Date: August 1, 2017 Not Recommended | Price: $93.00 | Rating: 7 

Pros: Centre is sharp, useful for m43
Cons: Corners are very weak on full frame
Sharpness: 7    Aberrations: 8    Bokeh: 5    Handling: 6    Value: 6    Camera Used: GX80, A7   

This is the first vintage zoom that I've bought, and although I've had great experiences with some vintage primes, I wasn't expecting miracles from an old zoom. I was interested in a zoom that would double as both a wide lens for full frame when hiking, and a walk-around zoom for shooting video on the micro-four-thirds GX80. Because native m43 lenses apply digital sharpening in-camera to video (which cannot be switched off), adapted lenses are essential to avoid a nasty video look.

The lens works great on the gx80, the 2:1 Crop factor removes the weak corners and sides and the 4K video and stills are sharp corner to corner even when wide open. It's pretty much stuck to my GX85 for daytime shooting. There are a couple of handling issues: the front element rotates, which is not ideal for use with polarising filters, and the focus drifts out when zooming. The focal range is equivalent to roughly 50-100mm, which is quite useful.

On Full Frame, it's not as positive. The corners and sides are very soft, and do not really get much better at f8 or f11. It's better at the longer end, but never marvellous. On the plus side, the colours are typically great Pentax.

I haven't got an APS-C camera to check if the worst of the sides and corners is cropped out, but I'd imagine that there is still some weakness visible, particularly at the wide end.
New Member

Registered: July, 2016
Posts: 1

5 users found this helpful
Review Date: July 4, 2016 Recommended | Price: $220.00 | Rating: 9 

Pros: Sharpness, IQ, built quality, perfect size
Cons: None if you can deal with manual focus
Sharpness: 9    Aberrations: 10    Bokeh: 9    Handling: 10    Value: 9    Camera Used: K1   

It's an old lens and not designed for the digital era, especially not for FF sensors with 36MP and pixel peeping.
Looking at my pictures and comparing the quality with the new D-FA 100mm Macro WR I'm not sure what they did back in this era. It's nearly perfect and my most used manual lens.

The results are sharp from center to the corners with only a slight, hard noticeable decrease in sharpness. The IQ is great - I've even not one picture to complain! Lens flares are possible but I was shooting the last two weeks in bright light where you're sometimes forced towards the sun without a hood and had only a few oportunities to get them. From other reviews I thought they would show more dominate, bigger and more clearly. When they happen they're noticeable but not very obvious. Half the time (I still got them only about ten times in ~2000 pictures) it took me two or three looks to be sure it's a lens flare.
The Bokeh is good, there's nothing to complain for a zoom lens.
The apperture make wonderful stars of bright light points!

Well, the built quality is really good, even my lens rattle a tiny bit when I force the focus ring sideways. I don't know if this is normal for this lens but it's not noticeable until I trying to force that kind of movement.
It's a decent size to make a wonderful walk around lens and the zoom range on a K1 fit perfect for city trips or landscape.
I used it while climbing for photos because of weight, size, stability and the range.
In a museum (Neues Grünes Gewölbe / Türkische Kammer / Münzkabinett im Stadtschloss Dresden) it was a bit to slow for their low light but still got good pictures.

Only the price I paid was a bit to high with 220€ since I was in a hurry.

Update: After half a year of comparing lenses, this is beside the D-FA 100mm WR and DA* 300mm my favourite lens. It's comparable in picture quality with these modern lenses and I'm still amazed about it.
No lens flares seen since my bright sun summer shooting, even without hood. Just one picture from my holiday remained with lens flares, all other were sorted out for different reasons but not for the lens flares.
Site Supporter

Registered: September, 2006
Location: North Idaho
Posts: 696

3 users found this helpful
Review Date: June 29, 2016 Recommended | Price: $138.99 | Rating: 9 

Pros: compact, well built, nice focal length range
Cons: no built in hood, flare when shooting into the sun
Sharpness: 10    Aberrations: 9    Bokeh: 8    Handling: 10    Value: 10    Camera Used: K-1   

I purchased this lens last April in anticipation of receiving my pre-ordered K-1. I have not been disappointed in the least...well mostly. It is very solidly built. Solid as a "tank". Even though it is a manual focus lens, focusing was very easy and accurate.

Shortly after receiving the K-1, I ordered and received the new D FA 28-105/3.5-5.6 thinking that I would use it the most as a travel snapshot lens. However, I quickly switched to using the A 24-50/4 exclusively, unless I needed the extra reach. The colors of the 24-50/4 are so much more vibrant. It is also four millimeters wider, which really made a difference in landscape shots.

Now for the "bad". I wished this lens had a built-in hood. I took one shot where I was shooting toward the sun and there is a bit of flare in the image. A sun hood would have taken care of that. I'm going to go out and find one to use with this lens. Otherwise, I have nothing negative to say about this lens. It's reputation is well-earned and accurate.

Got this lens off the "bay" and probably paid a little more than average. I was willing to do so because I was assured that it was a pristine example of this lens. I can very highly recommend this lens for anyone who is comfortable with manual focusing and needs a wide to normal high-quality zoom.

Junior Member

Registered: March, 2014
Posts: 27

3 users found this helpful
Review Date: March 10, 2015 Recommended | Rating: 10 

Pros: great sharpness for a zoom, sharp across the frame, sturdy, nice handling & size, great minimal focus distance, fixed maximum aperture
Cons: tiny bit of CA full open
Sharpness: 9    Aberrations: 9    Bokeh: 8    Handling: 10    Value: 10    Camera Used: LX, GH3   

Compared this lens at its wide end (24mm) to the Minolta MD Rokkor 24-50mm f4, which was a more expensive zoom and has a great reputation. The Pentax lens gave me better results in side by side tests so I ended up selling the MInolta. The Minolta had slightly better sharpness in the center, but towards the corners the Pentax wins comfortably at f4 and f5.6. It also is smaller (filter 58mm vs. 72mm), and has a minimal focus distance of only 40 cm (vs. 70cm). Finally the distortion at 24mm was better corrected.

Recently tested it against the Olympus 24mm f2.8, and while being a bit less sharp at f4 and f5.6 (only when pixelpeeping), from f8 I can't tell the difference, equally sharp across the whole frame. Being a zoom, I think this lens is very, very good and I feel no need to get a prime 24mm Pentax. Will be great on the FF digital Pentax...
Inactive Account

Registered: October, 2010
Location: Baltimore
Posts: 2,542

4 users found this helpful
Review Date: March 3, 2015 Recommended | Price: $50.00 | Rating: 10 

Pros: Superb at 24mm, A Lens, Sharp
Cons: None

I purchased this lens just for the 24mm end and it has not disappointed.

It performs very nicely and can almost pass for a "Stack of Primes". Easy to focus, it's a Pentax SMC- A lens and OOC images are superb. Very compact, 2 touch zoom (which I prefer) and a constant F4 throughout zoom. It's become my go-to lens...

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Veteran Member

Registered: January, 2012
Location: Wisconsin
Posts: 898

3 users found this helpful
Review Date: August 19, 2012 Recommended | Price: $150.00 | Rating: 9 

Pros: Most useful of all A lenses for walk around lens on crop DSLR. Quite compact for what it is.
Cons: Nothing stands out.
Sharpness: 8    Aberrations: 8    Bokeh: 8    Handling: 10    Value: 9    Camera Used: K20D, K1000, Super Program   

This lens makes an excellent walk around lens for any camera, but it is especially useful on my crop sensor K20D where all the rest of the A series zoom lenses don't go wide enough to be useful and any A series primes wider than the 35mm cost too much when you can even find them. The 24mm is wide enough for whole scenes or large objects, and the 50mm can be used to snap individual people from a distance. You won't be using this for many flower pictures though, it works OK but its sorta the anti macro lens, more suited to fields of flowers.

It can be a tad slow indoors or in low light compared to a prime but at about 400 ISO which is easy to do in high quality with modern film or even my somewhat older K20D, its perfectly fine. Its a short enough zoom range where you can get away with picking a middle number like 35mm for the shake reduction to have it work just fine, though I usually turn it off anyways by habit.

My like new copy has very thin grease in it which makes the zoom ring almost undampened and it has a tiny amount of side play in in the front element/zoom ring(the grease normally takes that up in these lenses), this could be fixed with a servicing but it doesn't effect the pictures so I haven't bothered yet.

I bought the correct Pentax screw on rubber lens hood for this and it works well on this lens even on FF film cameras at 24mm. I would recommend a hood and possibly even a protective filter as the very flat outer lens element is almost level with the end of the lens so its VERY easy to put finger prints on it or damage it though I have avoided this so far.

The lens overall is very compact for what it is and does and is just big enough to make a good grip without unbalancing the camera or making it a bother to carry around in a bag with the lens cap on.

The ability of this lens to be useful on all my K mount cameras of any era or sensor size has made it one of my most necessary lenses.
Inactive Account

Registered: October, 2010
Location: Reposaari
Posts: 25

2 users found this helpful
Review Date: December 22, 2011 Recommended | Price: $300.00 | Rating: 9 

Pros: IQ, mechanics, handling
Cons: Bokeh, sharpness
Sharpness: 8    Aberrations: 8    Bokeh: 8    Handling: 10    Value: 10   

First time writing an opinion on a lens... this might just emphasize the value I put on this piece of glass.

Starting with the negatives:

- this glass is sharp, no doubt about that. But if sharpness is a priority, you will do better with the manual primes or with some of the newer lenses.
- bokeh is a bit weird. I don't know why, but to my taste bokeh should be "dreamier" than what this lens produces. It is not bad, but something is not perfect in this regard.

On the other hand:

- IQ is great, even though bokeh and sharpness are not top notch. This lens delivers, it is a work horse!
- handling is really enjoyable. You have a good feel about the lens, focus and zoom rings very well designed. I just wished all other lenses would provide this solid operability.
- mechanics is great. I've had this one for a while, bumped it against what not obstacles, having filers removed from damaged threads, reworked at repair shops, and back on the road again... just great.
- the zoom range is perfect for a walk-around lens on a cropped digital system. You may need a wide angle and a tele in addition, but for myself this lens does most of my stuff.
Veteran Member

Registered: March, 2011
Location: Arizona
Posts: 330

2 users found this helpful
Review Date: November 3, 2011 Recommended | Price: $150.00 | Rating: 8 

Pros: Small, light, fun, build quality
Cons: Low sharpness
Sharpness: 7    Aberrations: 8    Bokeh: 7    Handling: 10    Value: 10   

Love this little lens. It is very compact and light, has good build quality (not amazing but good), does not color fringe, and it is so fun to use. The zoom range is not that bad even on digital (similar to a 35-75 on FF), anything wider than 24 I am using primes anyways. The sharpness is a bit low though, the lowest sharpness of all my lenses. Stopping down to 6.3 seems to be close to the sweet spot. Regardless I love this lens. The nice zoom range, compact size, and just the joy I get when I use it makes me love this lens. There are 4 lenses I have which I will never sell or trade the: FA* 300mm 2.8, Zeiss 28mm 2.0, DA 15mm 4.0, and A 24-50mm 4.0.
Veteran Member

Registered: November, 2009
Location: Strand
Posts: 1,366
Review Date: August 12, 2011 Recommended | Price: $180.00 | Rating: 10 

Pros: Useful focal lengths, sharp
Cons: manual focus
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 10   

If you need only f4, this lens is superb. Sharp all focal length, even sharper than some of my prime lenses. To have bokeh, the object needs to be closer than 5-6 feet /1.5-2 meter. Very good value for IQ. Another 'stack of primes' :ugh:
Veteran Member

Registered: May, 2010
Location: Veluwe
Posts: 339

1 user found this helpful
Review Date: November 3, 2010 Recommended | Price: $150.00 | Rating: 9 

Pros: great colours
Cons: --

Bought it to complement my other smc A zooms.
I consider it a sort of a zooming prime.
It has adequate resolution, great colours and it hardly "fringes".
The way it deals with contra light is amazing, even though it is sensitive to it. Use a really good hood!!! I do and it reminds me of the way the da15ltd handles this type of light.

I love the lens.
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