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SMC Pentax-M 50mm F4 Macro

Reviews Views Date of last review
26 139,701 Sat June 16, 2018
Recommended By Average Price Average User Rating
100% of reviewers $103.61 9.36
SMC Pentax-M 50mm F4 Macro

SMC Pentax-M 50mm F4 Macro
SMC Pentax-M 50mm F4 Macro

This slow macro lens was succeeded by faster A, F, FA, and D-FA versions.

SMC Pentax-M 50mm F4 Macro
©, sharable with attribution
Image Format
Full-frame / 35mm film
Lens Mount
Pentax K
Aperture Ring
Yes (no A setting)
Automatic, 5 blades
4 elements, 3 groups
Mount Variant
Check camera compatibility
Max. Aperture
Min. Aperture
Min. Focus
23 cm
Max. Magnification
Filter Size
49 mm
Internal Focus
Field of View (Diag. / Horiz.)

APS-C: 32 ° / 27 °
Full frame: 47 ° / 40 °
Not needed
Dedicated hard case
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Diam x Length
63 x 42.5 mm
160 g
Production Years
1977 to 1984
Engraved Name
smc PENTAX-M MACRO 1:4 50mm
Product Code
User reviews
Manual FocusAperture RingFull-Frame SupportDiscontinued
Price History:

Add Review of SMC Pentax-M 50mm F4 Macro
Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 1-15 of 26

Registered: May, 2014
Location: Linz
Posts: 631

1 user found this helpful
Lens Review Date: June 16, 2018 I can recommend this lens: Yes | Price: $60.00 | Rating: 9 

Pros: Sharp, small, light, well built, Aberrations
Cons: Aberrations
Sharpness: 10    Aberrations: 7    Bokeh: 8    Handling: 10    Value: 10    Camera Used: K-3   

The SMC Pentax-M Macro 1:4 50mm lens is a small and for its metal build a relatively light lens. Despite beeing over 30 years old my specimen looks like new and from the good impression the build quality makes I have no doubt that this lens will operate for another 30, 40 years with ease if you don't misuse it.

The focus ring is well damped and allows with its long focus throw precise adjustments especially for macro shots, although this also makes focusing a little slow I like this feature a lot.

The lens has good sharpness across the frame even wide open and as others have said before you can use it conveniently in Av mode for general photography (In Av mode on the camera this lens won't stop down, no matter what position your aperture ring has, because there is no communication between camera and lens!). Although other primes like my SMC Pentax-A 1:1.7 50mm are sharper, stopped down to f4.0, than the 50mm Macro is at f4.0, you get the advantage of a perfectly circular aperture against the hexagonal one from my A 50mm F1.7 lens at this aperture.
Stopping down the SMC Pentax-M Macro 1:4 50mm lens 1 or 2 stops will give you the best results for sharpness and you will have a hard time finding a sharper lens than this.

Now let's get to Aberrations, which I mentioned as pros and cons alike. First of all I didn't find any significant amounts of cromatic aberrations or purple fringing in my pictures, so those are well controlled with this lens. But it is an older lens with dated coatings so you get some optical features to contemplate. When you shoot against the sun for instance you loose contrast in your pictures and if the sunlight hits your lens in just the right angle some areas in the picture can get a little purple colour cast (aperture wide open). I actually like and provoke this effect when taking portraits in backlight situations.
But what is an advantage in certain situations can be a disadvantage in other ones, for instance is the same effect responsible for a blue colour cast around streetlights in nightphotography which is terrible to remove in pp.

All in all I like this lens very much and I use it primarily for portraits, landscapes and macrophotography but there isn't really much you can't use it for in daylight.
For nightphotography or artificial lighting I would favour other lenses not just because of the small aperture f4.0 but also because of the mentioned colour cast that can occur in certain situations.

Last but not least some samples:
Cactus by Patrick Bittermann, auf Flickr
Greenhouse by Patrick Bittermann, auf Flickr
Weide by Patrick Bittermann, auf Flickr
Höllmühlbach by Patrick Bittermann, auf Flickr
New Member

Registered: February, 2016
Location: lake constance
Posts: 1

1 user found this helpful
Lens Review Date: October 30, 2017 I can recommend this lens: Yes | Price: $70.00 | Rating: 10 

Pros: no distorsion, ultrasharp, light weight, high mechanical quality
Cons: I didn´t find any
Sharpness: 10    Aberrations: 10    Bokeh: 10    Handling: 10    Value: 10    Camera Used: Sony A7 and Pentax ME super   

I use this lens for digitalize my slides and BW infrared films with a Pentax A bellows.

Great sharpness, no distorsion and fine colour transmission. You don´t need any expensive scanner to do this job. Ok, you have to spend a little time to work on Photoshop, because of dust particles, but if you work carefully, it is almost easy.

After this correction you can make 30x40cm prints without imagine it as an analogue shot - almost unbelievable - and I did it with an simple AGFA CT100.
I want to shoot with Fuji Velvia 100 professional in future and I expect even larger prints of high quality.

I can recommend this macro also for "normal" photography. It is light weighted and small.

An absolute bargain in my Pentax M lens collection - pick it up and keep it!!!

Junior Member

Registered: March, 2014
Posts: 27

2 users found this helpful
Lens Review Date: January 22, 2016 I can recommend this lens: Yes | Price: N/A | Rating: 10 

Pros: f4
Sharpness: 9    Aberrations: 10    Bokeh: 9    Handling: 10    Value: 10   

I love this size of macro lenses. It is very lightweight, 1:2 is more then enough, and it is as good as any 'normal' 50mm for landscapes etc.

I compared it with several Pentax 50mm, Zuiko 50mm and Minolta 50mm standard lenses (non macro) and while some other lenses beat it at f4, from f5.6 this is as good as any of them.
The lens is completely usable at f4 though, already at f4 the image is sharp allover including the corners. And what I like about f4 is that the aperture is round, while all the other normal lenses show hexagonals or octagonals because of being stopped down at f4.

So, when using this lens in normal daylight it will often be possible to use it fully open, giving its best bokeh! For best sharpness stopping down just 1 stop will do. I think it is great that the lens only uses 4 elements and that the formula (4 elements in 3 groups) stayed the same from the first Takumar version untill this M version. Highly recommended!
New Member

Registered: July, 2015
Posts: 1
Lens Review Date: July 24, 2015 I can recommend this lens: Yes | Price: $88.00 | Rating: 10 

Pros: Sharpness, perfectly flat field of focus
Cons: Kinda slow (f4)
Sharpness: 10    Aberrations: 10    Bokeh: 10    Handling: 9    Value: 10    Camera Used: OMD EM1   

Just picked this up on EBay. In stellar condition, no dust, no wear.

I'm using it adapted to my Olympus OMD EM1, which is kind of a waste, considering much of this lens' perfectly flat field of focus is eliminated by the crop factor, but it's the best macro I could find for the money. It's sharp as a freaking tack.

It actually looks kinda cool with that Kmount-M4/3 adapter!

Micro 4/3 full frame, maximum enlargement ratio, 1:2

Forum Member

Registered: January, 2015
Posts: 71
Lens Review Date: April 19, 2015 I can recommend this lens: Yes | Price: $70.00 | Rating: 10 

Pros: VERY sharp, lightweight, nice bokeh at f/4, long smooth throw for critical close focus
Cons: Slow, tough to focus near infinity, not 1:1, less than perfect bokeh stopped down (5 blades)
Sharpness: 10    Aberrations: 10    Bokeh: 8    Handling: 9    Value: 10    Camera Used: K-50   

I recently found one of these with an ME Super in a Fleabay auction light on details and with a cryptic title. I recognized this gem hidden in one of the (dark & out of focus) images and decided it was well worth the flyer for this low price. It showed up in good shape with more internal dust than I had hoped but with all mechanical parts working normally and otherwise clean glass. I am considering sending it in to Eric for a CLA (~$40) but I'm not sure that it's even necessary, as the images I'm getting are really nice as is.

This is a crazy sharp lens that is optimized for close focus. There is a solid chance this is the sharpest lens I currently own. If you use it for its intended purpose it's tremendous. Perfect for depth of field still life close ups when tripod mounted (product photography, food, etc.) and also wonderful as a walkaround 1:2 macro lens in good outdoor light due to its small size and light weight. Sure it has its limitations, but you can't have it all especially at the price range we're talking about here. It doesn't go to 1:1, it's not long enough to give a good working distance for insects, it's tough to focus near infinity, it's pretty slow, and the focus throw is too long to work well for anything moving quickly. You shouldn't buy this lens if any of these things are important for you...they are all capabilities you can get elsewhere if you need them and want to pay for them.

Bokeh is circular and smooth wide open but less so stopped down (5 blades). Luckily it is sharp enough at f/4 to just stick to that aperture when bokeh is desired.

I started to play around with it for portraits at f/4 and this could also be interesting...I liked the previous reviewer's recommendation of leaving it wide open at f/4 and using Av mode and I'm going to give this a try.

If I could give this purchase a 12 for value I would.

On a walk today at f/4, handheld, ISO 400. In retrospect I could have used more DOF but this should give you an idea of what this lens can do even wide open. This is straight from the camera uncropped and with no PP.

Edit: Added the cost of CLA to the purchase price

Registered: March, 2014
Location: Dallas, TX
Posts: 890
Lens Review Date: September 21, 2014 I can recommend this lens: Yes | Price: N/A | Rating: 10 

Pros: Compact. SHARP! Solid Build. f/32 aperture setting. Light and Portable
Cons: Wish it was a bit faster. No "A" setting. Not 1:1 Macro (1:4)
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 10    Camera Used: K500   

Can't say enough good things about this lens. The M and K series 100mm f/4 Macros seem to get all attention, but this lens is amazing and deserving of some attention. On an APS-C body it makes for a very nice walk-around lens performing extremely well in non-Macro, as well as Macro situations. Nice to know that you can have one lens that will likely accommodate whatever you come across in your walk-around. With this level of sharpness, crops are not a problem so situations where the 50mm is a bit of a stretch present no issues. The color rendition and contrast is stellar while the edge-to-edge SHARPNESS cannot be over-stated.

If you don't have one and are not intimidated by a full manual lens -- GET ONE!! You will not be sorry. Below are some captures for my PF "Single In... " challenge w/ this lens...

IMGP2164 by Ripper2860, on Flickr

IMGP2240 by Ripper2860, on Flickr

IMGP2406-2 by Ripper2860, on Flickr
New Member

Registered: August, 2013
Posts: 11
Lens Review Date: December 20, 2013 I can recommend this lens: Yes | Price: $40.00 | Rating: 10 

Pros: Sharpness & Build Quality
Cons: Still searching...
Sharpness: 10    Aberrations: 8    Bokeh: 8    Handling: 10    Value: 10    Camera Used: Kr   

Wow, I'm very impressed by this lens, it's just amazing how sharp it is! Sharp wide open at F4 from the middle to the corners.

Shooting in A mode (always at F4) is really simple and it gives very great results, I felt it would be a bit hard to use in M mode but it's just an habit to take (green button).

It's real pleasure to shoot with this lens, it deserves a 10!
Veteran Member

Registered: February, 2009
Location: Arlington, VA
Posts: 3,758
Lens Review Date: October 19, 2013 I can recommend this lens: Yes | Price: N/A | Rating: N/A 

Pros: sharp, sharp, sharp
Cons: lacks contrast a bit, esp. wide open
Sharpness: 9    Aberrations: 10    Bokeh: 9    Handling: 10    Value: 10   

I'm not going to insist on the qualities of this lens--what the others said is true. Tiny, lightweight, all metal. Decent macro, but excellent for landscape, streets. The lens is very sharp corner to corner right from f4; @f5.6-f8 is one of the sharpest lenses I've seen. I've taken some occasional portraits with it, too, and the bokeh isn't bad at all. (The only problem: I had to soften the pics in PP.) Lacks a bit of contrast, but this is no issue if you shoot raw. Very natural colors, may need to be bumped in PP (although bumping the contrast is in most cases sufficient).

Now I'm letting images speak (taken with K-x--click on the pics to enlarge them):

Senior Member

Registered: May, 2013
Location: BC
Posts: 138
Lens Review Date: September 11, 2013 I can recommend this lens: Yes | Price: N/A | Rating: 9 

Pros: Sharpness & Build Quality
Cons: Manual everything (but hey it is a M lens afterall)
Sharpness: 9    Aberrations: 8    Bokeh: 9    Handling: 9    Value: 9    Camera Used: K100D   

sharp at f4 and just improves when stopped down. Not really the best macro lens but it works for a general 50mm "close-up" purpose.

Compact size, sharp, nice bokeh are all pros for this lens

at f8

at f4
Veteran Member

Registered: November, 2012
Posts: 960

1 user found this helpful
Lens Review Date: August 12, 2013 I can recommend this lens: Yes | Price: $93.00 | Rating: 9 

Pros: Sharp! Very good dampening!
Cons: It could have been faster. A pseudo-macro
Sharpness: 9    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 10    Camera Used: K-x   

This is a very sharp lens. I bought this lens out of curiosity, as I already have a real macro in the form of DFA 100WR. I already have a lot of 50mms too.

Still, there's something special in it's unassuming image character/rendition that defines this lens. It's a slow lens, at f/4, but it definitely has the Pentax pixie. It may as well be a brother to my K55/1.8! That's how good this is!
New Member

Registered: December, 2011
Location: Perth, Western Australia
Posts: 22

1 user found this helpful
Lens Review Date: December 8, 2012 I can recommend this lens: Yes | Price: $70.00 | Rating: 10 

Pros: Sharp and compact
Cons: None yet...
Sharpness: 10    Aberrations: 9    Bokeh: 7    Handling: 10    Value: 10    Camera Used: K5 classic   

I picked this lens up through eBay in Australia, I feel it truly is a sleeper lens in the M line-up.

I've had it for a day and my first impressions are very good. The fact that it isn't a 1:1 macro is a non issue for me, I'm not really a macro shooter, so 1:2 leads me into the hand held, every day macro world without having to use ring flashes etc.

The biggest unexpected bonus with this lens is the sharpness, as a walk around 50, it's very sharp and the bokeh isn't too bad either, I own the 43, 77 and 15 limiteds, so I know what sharp looks like! This lens compliments my current line up well, it doesn't have the mojo of those 3 jewels, but for $70, it's a no-brainer!

The way it renders blue skies is very rich, also an unexpected bonus!

My copy is very clean and looks hardly used, most copies I see on eBay are in similar condition, it looks like they're just not heavily used by anybody! The focus helicoid is very damped, which makes close focussing easier, compared with the M1.7 focus damping, it's very nice, the M 1.7 is too loose for me.

In closing, if you see this lens for sale people, buy the thing, you'll love it... use it as a street lens first, it's great!
( just get in before the word gets out and the price goes crazy like the Taks did!)

Happy Shooting!


Junior Member

Registered: November, 2012
Location: Cosenza
Posts: 42

1 user found this helpful
Lens Review Date: December 7, 2012 I can recommend this lens: Yes | Price: $90.00 | Rating: 9 

Pros: sharpness, size, colors
Cons: only f/4
Sharpness: 9    Aberrations: 9    Bokeh: 9    Handling: 8    Value: 10    Camera Used: Canon Eos 5D Mark II, Pentax ME Super   

At the link below you can see how it performs at all stops compared to various other 50s-ish: the 50mm f/1,4 Takumar 8-elements design, the S-M-C 7-elements variant and a few others 50s (Contax Makro Planar, Minolta MD, Olympus OM Zuiko):

It would be basically a great bargain anyway, but at the actual ridiculously low price tag it's a "must have" lens, even if you, like me, don't do macro.

It gives you almost the same quality of the Contax Makro Planar, but in a package that weights maybe one forth!

As a dedicated macro lens I would have some reserve, but only because it doesn't reach 1:1 by itself; this may or may not bother you at all.

BTW, I gave it an 8 for handling, instead of a 9, only because I'm spoiled by the butter smooth focusing action of the old Takumars, not because there is anything wrong with the M macro.

To use it on a Canon full format (and possibly even on an aps-c, but I haven't tried), you'll need to file down or cut with a Dremel-like tool the rear aperture fin and the metal lip that protects said fin; it's pretty soft metal, all the procedure - included the time spent wrapping the lens in aluminum foil to avoid dirt entering the lens itself - it will take maybe 10 seconds top.

If you want to avoid the hassle just buy the m42 version. I didn't only because I wasn't able to find one at the right price at the right time. Yep, patience is not my strong suit
New Member

Registered: October, 2012
Posts: 1
Lens Review Date: October 23, 2012 I can recommend this lens: Yes | Price: N/A | Rating: 10 

Pros: Ridiculously sharp, zero distortion, superb build, makes a surprisingly good street lens
Cons: Not very macro
Sharpness: 10    Aberrations: 10    Bokeh: 8    Handling: 10    Value: 9    Camera Used: Pentax ME Super   

This lens is one of my favorite 50's ever. The way it renders images is surreal; so unbelievably sharp and pristine. It's macro capability is good, but honestly I used this as a walk-around and street lens more often. It might even be too sharp, but it makes an amazing portrait lens too. Yes, it is f/4 but the images are stunning.
New Member

Registered: July, 2011
Posts: 8
Lens Review Date: July 29, 2012 I can recommend this lens: Yes | Price: $100.00 | Rating: 8 

Pros: Sharpness, macro ability
Cons: only f/4, magnification only 1:2
Sharpness: 9    Aberrations: 9    Bokeh: 7    Handling: 8    Value: 9    Camera Used: K-5   

You cannot have all in one lens. This lens is sharp, just like the 50 1.7. I would prefer to have the combination of both: sharp, a close focus ability and the possibility to open up the lens wide (f/2 or wider). Unfortunately, this ideal lenses do not exist - or if so, they are extremely expensive. For what you can expect from the specs (1:2 magnification, f/4 aperture), this is as good as it can be. Nice colors, great build. Surprise: the front lens element is located very far inside the lens, so the probability of scratches on the lens is very low: good news for the potential buyers of this older lens...

I would have given the lens a 8,5 if possible.
Site Supporter

Registered: November, 2010
Location: California
Posts: 2,223
Lens Review Date: April 7, 2012 I can recommend this lens: Yes | Price: $154.00 | Rating: 10 

Pros: The best landscape lens
Cons: None (well, maybe the 1:2 ratio could be 1:1)
Sharpness: 10    Aberrations: 10    Bokeh: 10    Handling: 10    Value: 10   

This was my macro lens until I purchased the TamronSP90/2.8 that gives me 1:1 ratio. However, in a John Shaw book about landscape, I learned that this lens could be one of the best landscape lenses. Here is a sample I took:

Pentax-M 50mm f4 Macro - Great landscape lens by Palenquero, on Flickr
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