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

SMC Pentax-F 24-50mm F4

Reviews Views Date of last review
10 143,432 Sun June 10, 2018
Recommended By Average Price Average User Rating
100% of reviewers $150.22 9.30
SMC Pentax-F 24-50mm F4

This is the autofocus successor to the A-series 24-50mm zoom lens which has the same optical formula.

SMC Pentax-F 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
AF (screwdrive)
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 60mm clip-on
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Diam x Length
70 x 67 mm (2.8 x 2.7 in.)
380 g (13.4 oz.)
Production Years
1987 to 1998
Engraved Name
smc PENTAX-F ZOOM 1:4 24-50mm
Product Code
User reviews
Screwdrive AutofocusAperture RingAutomatic ApertureFull-Frame SupportDiscontinued
Price History:

Add Review of SMC Pentax-F 24-50mm F4
Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 1-10 of 10
Veteran Member

Registered: October, 2006
Location: Belgium
Posts: 476

14 users found this helpful
Review Date: June 10, 2018 Recommended | Price: $175.00 | Rating: 10 

Pros: Sharpness, handling, compactness, price second hand
Cons: Filter barrel rotates with focus, Some CA
Sharpness: 9    Aberrations: 8    Bokeh: 8    Autofocus: 8    Handling: 10    Value: 10    Camera Used: K-1, K-5, K20D, *ist D, MX   

For those who don't want to read long texts and just want a summary: this is an excellent lens that won't disappoint, especially given the fact that it is a zoomlens of which the optical formula dates back forty years ago. Both on ff (K-1) or APS-c the 24-50 sets a performance that is plain unbelievable and I would rate the IQ easily in DA 20-40 Limited territory. Some distortion (only on 24mm) and some CA is about the only thing you will have to complain about. For the price this lens fetches second hand it is a no brainer!

I have had this lens 4 times: 2 F-versions and 2 A-versions. Used it on many cams (including MX, K-5 and K-1) and I really love it. If you like manual focus, you will probably want the A-version, but apart from that it is difficult to tell them apart. Suffice to say that all 4 had a very similar performance.

Compact, this lens handles easily with any camera you would want to pair it with. Even with the MX, handling is excellent and the lens is not front heavy. Zooming is positive and the zooming ring is big enough. Focus ring on the F-version is very small (as with any autofocus lens of that area) and that is why I advice the A-version if you are going to focus manually a lot. Autofocus is fast and precise even on the K-5 (there are faster focusing lenses out there, but since I can hardly imagine doing any sports with the 24-50 I think it won't ever be an issue.) Two things of note (valid for both F- and A-version): a) focus throw is short (+/- 100 for F-version, +/- 140 for A-version, an extra reason to look for an A-version if manual focus is important to you) which means that precise manual focus needs a little getting used to, b) filter thread turns with focusing, which makes the use of polarizing and effect filters a little cumbersome. In fact, this is my main gripe with this lens.

This lens matches (and sometimes betters) the 20-40 Limited for sharpness, enough said.
- On the K-1, corners are on the soft side @24mm wide open and never reach the level of sharpness of the center. From 28mm and beyond, they play at the same level. Sharpness is a little less @50mm but even then plain usable, even wide open.
- On APS-c it's all very good to excellent. Diffraction is only an issue from f/16.

Here's a (granted, personal) summary:
Full Frame
- 24mm: 6/7 (corners, f/4) - 8/9 (center, f/4) - 7/8 (corners, ≥f/4) - 9 (center, ≥f/4)
- 28mm: 7/8 (corners, f/4) - 8/9 (center, f/4) - 7/8 (corners, ≥f/4) - 8/9 (center, ≥f/4)
- 35mm: 8 (corners, f/4) - 8 (center, f/4) - 8 (corners, ≥f/4) - 8/9 (center, ≥f/4)
- 40mm: 8 (corners, f/4) - 8 (center, f/4) - 8 (corners, ≥f/4) - 8/9 (center, ≥f/4)
- 50mm: 7 (corners, f/4) - 7 (center, f/4) - 8 (corners, ≥f/4) - 8 (center, ≥f/4)
- 24mm: 8 (corners, f/4) - 8/9 (center, f/4) - 8 (corners, ≥f/4) - 9 (center, ≥f/4)
- 28mm: 8 (corners, f/4) - 8 (center, f/4) - 8 (corners, ≥f/4) - 9 (center, ≥f/4)
- 35mm: 8 (corners, f/4) - 8 (center, f/4) - 8 (corners, ≥f/4) - 9 (center, ≥f/4)
- 40mm: 8 (corners, f/4) - 8 (center, f/4) - 8 (corners, ≥f/4) - 9 (center, ≥f/4)
- 50mm: 8 (corners, f/4) - 9 (center, f/4) - 8 (corners, ≥f/4) - 9 (center, ≥f/4)
-There is some barrel distortion @24mm, but the level (about 1%) is lower than that of the 20-40 Limited, and it is of no concern from 28mm on.
-The Achilles heel of the 24-50 is the level of CA. However, it cleans up nicely in Lightroom and Capture One, although it will never get rid of some traces of color fringes on edges of high contrast areas (especially in the corners.) These will only be visible in special occasions (ie. leaves against a backlit sky.) Although present at all settings, the problem is of higher concern @24mm (IMHO, this is why corner sharpness drops @24mm.) Accordingly, CA is of a bigger concern when used on a K-1 (ff) than on an APS-c camera.

I am not a bokeh expert and the lens' specs will never make it a bokeh king, but IMHO you can make pictures with pleasing bokeh.

When I figure out how to include photo's to this review I will include some examples...
New Member

Registered: January, 2017
Posts: 1

1 user found this helpful
Review Date: January 9, 2017 Recommended | Price: $40.00 | Rating: 10 

Pros: FF compatible, Good sharpness and colors rendition through the zoom range, relative low cost (in my case)
Cons: Noisy AF
Sharpness: 9    Aberrations: 7    Bokeh: 8    Autofocus: 8    Handling: 8    Value: 10    Camera Used: Pentax K-5 and Fujifilm X-E1   

I collected this lens as a temporary low cost solution for the K-1.

This lens is part of a purchase consists of 3 lenses which cost me 110.

SMC Pentax 85mm (F1.8 K mount)
SMC Pentax-F 24-50mm F4
SMC Pentax-F 70-210mm F4-5.6

Therefore, the estimated price $40 (approx 1/3 of 110). The relative low cost is also taken into account for the overall rating 10.
It's not a high-end lens for sure, but I'm happy to have it as a temporary low cost solution fo my Pentax K-1, while saving for a good modern lens at a later stage.

A lot is already said about the IQ of this lens by other reviewers.
Attached are some photo's taken with this lens on both Fujifilm X-E1 and Pentax K-5.

Taken with Fujifilm X-E1 in good light @ F/6.3

Taken with Fujifilm X-E1 in good light @ F/6.3

Taken with Pentax K-5, inside the room with only window light, ISO500, F/8, 1/40s
New Member

Registered: September, 2016
Posts: 1

1 user found this helpful
Review Date: September 30, 2016 Recommended | Price: $230.00 | Rating: 8 

Pros: Kompaktowe wymiary, ladne cieple kolory, jak dluzej pouzytkuje to dopisze uwagi
Cons: Lekko nieostry w samych rogach
Sharpness: 8    Aberrations: 9    Bokeh: 8    Autofocus: 8    Handling: 8    Value: 8    Camera Used: Pentax K-1 , K-5IIs   

Site Supporter

Registered: December, 2010
Location: Colorado Front Range
Posts: 632

9 users found this helpful
Review Date: September 17, 2016 Recommended | Price: $175.00 | Rating: 10 

Pros: compact size, value, image quality, useful range
Cons: Front rotates while focusing, loud focusing
Sharpness: 9    Aberrations: 9    Bokeh: 8    Autofocus: 8    Handling: 9    Value: 10    Camera Used: K5IIs, K-1   

Let's see-- three years since this lens had a review. Big changes since then! Although I haven't yet made an exhaustive study of this lens on the K-1, I can give some preliminary judgements. I used it cropped on the K5IIs for a couple of years, and was always happy with the results. With the K-1, it's elevated to the next level.

Fun Fact *1-- This zoom lens is almost the same size and weight as the DA*55/1.4

A lens like this is essential to my K-1 system strategy. I didn't want the traditional trio of 2.8 zooms. That's too expensive, too heavy and too ostentatious in today's world, where phone cams are everywhere but large "pro" cameras seem threatening to many. Ten years ago I was using Sony's FF DSLR, the a850, and relying on a pair of f:4 zooms. That camera was pretty noisy, so surely f:4 will suffice on the K-1.

Fun Fact #2-- This lens mounted on a K-1 is 45 grams lighter than a DA*16-50 affixed to a K3II.

Whether on crop or full frame, I've never been disappointed by the F 24-50. Lately I've been comparing it to the 43 Limited, and I can't pick them apart for sharpness. I doubt this lens will match the elegant bokeh of the Limited -- it simply doesn't have the aperture, and it probably has aspherical lenses that can spoil bokeh-- but I haven't tested for that yet. Covering the three traditional prime lengths, 24, 35 and 50, the K-1 adds an effective 75mm focal length, as well. That's a ton of flexibility. A minimalist might add an ultrawide and a 200mm prime and call it a day.

Maybe I'm not the most discriminating and critical pixel-peeper among us. In fact, I'm sure I'm not. But since I got the K-1, I'm seeing a new level of detail and richness on my 27" screen. A lot of that is delivered by this lens. Let the pictures speak for themselves- I wouldn't know how to ask more from this lens. (This is the first time I've tried to load photos into a review. let's see if it works.)

Dadgummit! I can't figure out how to add photos. Moderator? In the meantime, they are available in my gallery under "nature"
Forum Member

Registered: February, 2011
Posts: 84

14 users found this helpful
Review Date: July 28, 2013 Recommended | Rating: 9 

Pros: Size, quick AF, really good stopped down just a bit.
Cons: Build quality, sometimes falls short in a few aspects
Sharpness: 9    Aberrations: 4    Bokeh: 8    Autofocus: 9    Handling: 7    Value: 8    Camera Used: K-5, K20D   

This is the second copy of the lens I have. The first one I disliked. The K20D somehow didn't go well with it IQ-wise, and it always felt like it was missing a few millimeters on the wide end too. I got rid of that. Now with K-5, I was looking at some of the old pics and remembered this lens - which some people hold in very high regard - and I found myself one again. I took it out with the K-5 a few times, and I'm happy with it now.

It's got a good angle for the times when you're not shooting anything in particular. The good walk around lengths are all there. The pictures look good, and overall it's a good lens. Not perfect, just good. Because there are times when you want to say what the h**f**gd**ck was I thinking. The 24-50, you see, has a personality. It does not like certain things, and if you try to feed those scenes to it, it will not draw a pretty picture; it will vomit instead. I mean really ruin the images. And then it will slap you, and then ruin the next few shots just because.

Build quality is pretty lousy. It's plastic - no not the good DA50 kind of solid plastic, but the bad kind of plastic. It feels a bit flimsy, and the rubber parts don't look so tight anymore. Focus ring is horribly lightweight with almost no resistance. That's a no for MF. Luckily the AF is quick and performs solidly, as this lens ends up being in AF mode about 100 % of the times you use it.

Stay away from MF. And situations where you shoot wide open closer to the 50mm end against the light, on a bright day. In fact, use the lens only ever so carefully on a bright day, to begin with. And please tend to stay away from f/4. If you look closely, you can tell from almost any picture if it's shot wide open, as there's signature blue flame shooting near edges on bright contrast situations. And, uh, don't go to 50. You have the nifty fifty for that. Only use the lens at tele end if you can't walk any closer. In short: it's wide, and find shade. Then it's OK.

Here it is wide open (30mm, f/4):

IMGP3931.jpg by jiimaa, on Flickr
(pixel peep the original res photo here)

But the moment you introduce any difficult light, wide open isn't usable (28mm, f/4):

IMGP3947.jpg by jiimaa, on Flickr
(pixel peep the original res photo here)

Stop it down one stop, and it all goes away (28mm, f/5.6):

IMGP3948.jpg by jiimaa, on Flickr
(pixel peep the original res photo here)

Here it is at it again, this time the wide open makes it halo like it was the master chief himself (45mm, f/4):

IMGP3913.jpg by jiimaa, on Flickr
(pixel peep the original res photo here)

...and, again, just one stop closed, the problem goes away (45mm, f/5.6):

IMGP3914.jpg by jiimaa, on Flickr
(pixel peep the original res photo here)

The bokeh is a more difficult thing to think about, as the f/4 is mostly useless aperture there's not much of it. But if you get it lured out, there's nothing wrong with it (28mm, f/5):

IMGP3878.jpg by jiimaa, on Flickr
(pixel peep the original res photo here)

Gets better naturally at longer focal length and closer focus point - which kind of defies the purpose of wide angle zoom, but hey I'm not judging anyone (40mm, f/5.6):

IMGP3918.jpg by jiimaa, on Flickr
(pixel peep the original res photo here)

Bottom line, it's a good lens, well worth the nines it's getting - just stick to the wider end, and don't f/4 too often unless you really have to (33mm, f/5.6):

IMGP3870.jpg by jiimaa, on Flickr
(pixel peep the original res photo here)

Added a few days later:

More testing.

Wide open performance sucks at hard contrast situations. Often totally useless images. If there's hard contrast, don't f/4. That said, the f/4 isn't completely useless - it does the trick from time to time, and in favorable situations it makes the image more pleasant. However, there's very little reason to go 4 instead of 5.6 as the benefits of 5.6 to aberrations are major, while f/4's input to bokeh and DOF are questionable at best as there's also a dip in overall sharpness.

The sharpest apertures start from f/5.6 and up to f/11. Beyond that IQ decreases again. Going beyond 5.6 is only necessary in difficult light - going f/9 almost entirely eliminates CA. Without any studio targets shot, after real world shots only, at 5.6-11 variance in sharpness is more due to me focusing wrong, than any kind of trend in specific apertures, so I see no other reason than hard contra light to go beyond 5.6.

I'm decreasing the aberrations, overall still worth the 9.

More examples:

24mm, f/4:

IMGP4198.jpg by jiimaa, on Flickr
(full size here)

40mm, f/4, cropped slightly:

IMGP4077.jpg by jiimaa, on Flickr
(full size here)

36mm, f/5.6:

IMGP4100.jpg by jiimaa, on Flickr
(full size here)

40mm, f/5.6:

IMGP4169.jpg by jiimaa, on Flickr
(full size here)

30mm, f/6.3:

IMGP4087.jpg by jiimaa, on Flickr
(full size here)

24mm, f/9:

IMGP4044.jpg by jiimaa, on Flickr
(full size here)

24mm, f/9:

IMGP4222.jpg by jiimaa, on Flickr
(full size here)

36mm, f/9:

IMGP4211.jpg by jiimaa, on Flickr
(full size here)

One last edit: I've lost my faith again - there are just too many missed shots because of the tendency to fsck up any and all hard light shots. I'm throwing you to the wolves again 24-50, that's two times now, how's that feel. That's right - about the same I felt when I looked at the pics of the last session you fell short at.

I don't want to change my shooting patterns over one lens, so it's someone else's turn.

I'm decreasing the aberrations again....
New Member

Registered: May, 2012
Posts: 14

1 user found this helpful
Review Date: May 15, 2012 Recommended | Price: $180.00 | Rating: 10 

Pros: Very sharp, good color rendition and contrast and quick auto focus
Cons: Could have been 2.8 to be the perfect lens
Sharpness: 9    Aberrations: 8    Bokeh: 7    Autofocus: 9    Handling: 10    Value: 10    Camera Used: K-5, K-20, K-m   

This is a very good surprise! This is very sharp lens i could compare at 40mm F8 to my DA 40mm 2.8. Color rendition and contrast are super, I don't need hours of post-production on Lightroom. The autofocus is also very fast focusing.

The 24-50mm is my most used focal range beinf the perfect lens for me. I just would love to be a faster lens so it could replace my tamron 17-50mm.

What else could I say about this lens, i just love it!
New Member

Registered: April, 2011
Posts: 2

2 users found this helpful
Review Date: July 21, 2011 Recommended | Price: $160.00 | Rating: 9 

Pros: Image quality, sharp at all apertures.
Cons: None

This is an excellent lens for general use on APS-C and can be obtained for a very reasonable price.
The 24-50mm range is very useful and personally I find that 24mm is wide enough
for most of my work.
Image quality is very good and this lens is sharper at all apertures than my FA 28-70mm. When stopped down to f8 images are almost indistinguishable from those taken with my primes.
I can thoroughly recommend this lens.
New Member

Registered: January, 2009
Location: Poland
Posts: 4

2 users found this helpful
Review Date: March 7, 2011 Recommended | Price: $132.00 | Rating: 9 

Pros: Sharp, excellent color
Cons: Rotating front barrel

Light weight, sharp, great for travel. Very good lens as a walkaround lens on APS-C. Nice color rendering from this lens. I very like this lens.
Veteran Member

Registered: June, 2008
Location: Madison, WI
Posts: 2,165

2 users found this helpful
Review Date: February 26, 2010 Recommended | Price: $160.00 | Rating: 9 

Pros: nice range, decent close-ups, constant aperture, film compatible
Cons: occasional light bleeding at high contrast edges

Very handy walk-around lens on APS-C sensor, wide angle to normal zoom on film. Decently sharp wide-open, even better stopped down slightly. Not quite as good IQ as the FA 20-35mm, with which I replaced it.
Forum Member

Registered: March, 2007
Location: TN
Posts: 58

1 user found this helpful
Review Date: January 5, 2008 Recommended | Price: $100.00 | Rating: 9 

Pros: sharp, nice contrast

Nice solid lens that works well on both film and digital. No creep, well built, and covers some good focal lengths, although it's not really a wide angle on digital with the crop factor.
Add Review of SMC Pentax-F 24-50mm F4

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