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SMC Pentax-M 50mm F4 Macro Review RSS Feed

SMC Pentax-M 50mm F4 Macro

Reviews Views Date of last review
35 193,706 Sat February 4, 2023
Recommended By Average Price Average User Rating
100% of reviewers $100.00 9.32
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 35
New Member

Registered: February, 2021
Posts: 21

1 user found this helpful
Review Date: February 4, 2023 Recommended | Price: $40.00 | Rating: 9 

Pros: Sharp, small, fun, nice colors
Cons: Can't pronounce because I know little about photography...
Sharpness: 9    Aberrations: 8    Bokeh: 8    Handling: 9    Value: 10    Camera Used: K30   

I bought this lens because I didn't have any macro lenses, as new and modern lenses are very expensive and on the other hand vintage lenses have a certain charm and a very special use, I found the Pentax 50mm Macro f4 for a good price. However, it was full of fungus on the lenses, see the first photo, after investigating a little on the net, I took the lens apart, cleaned the lenses with 99.5% isopropyl alcohol, lens cleaning liquid, and finally, before assembling, I sterilized everything in a UV box and ozone. Not even being an amateur in these works, I think the lens turned out fine, at least for me, and I've been having a lot of fun taking pictures. I post some here. Thank you all for this magnificent Forum !!!

New Member

Registered: June, 2020
Posts: 2
Review Date: September 7, 2021 Recommended | Price: $120.00 | Rating: 6 

Pros: Compact, ok sharp from f4
Cons: Sometimes has internal flare and dull colors, bokeh is awful, less sharp than most other lenses from the same era
Sharpness: 7    Aberrations: 9    Bokeh: 4    Handling: 8    Value: 6    Camera Used: Nikon Z5   

It works excellent on crop sensors due high center resolution. On FF sensors, sometimes, gives strange color cast wide open. Bokeh depends on lighting condition and it is, in most cases - ugly. I found it in the same league as Olympus 50/3.5, where Olympus has slightly better bokeh.

Minolta MD 50/3.5 has better bokeh and colors on FF sensor.
Nikkor P.C. 55/3.5 has overall higher resolution on crop and FF sensors.

In general, very good lens.
New Member

Registered: August, 2017
Location: Ronneburg
Posts: 1
Review Date: August 10, 2021 Recommended | Price: $80.00 | Rating: 10 

Pros: sharp, solid M build,
Cons: The SMC Pentax-M 50mm F4 Macro Lens isn’t capable of 1:1 ratio
Sharpness: 9    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 10    Camera Used: K-3   

This lens is great for landscape work, and is almost good for portraiture, although some might say that it’s “too sharp” for that type of composition.

This lens isn’t a true macro lens, as it isn’t capable of shooting at a 1:1 ratio, making it difficult to shoot close subjects that are fast moving. For its magnification capabilities the user sacrifices shutter speed for zoom, but this lens is versatile and capable in many other situations.

Registered: December, 2013
Location: West Virginia
Posts: 2,756

1 user found this helpful
Review Date: April 5, 2021 Recommended | Price: $84.99 | Rating: 10 

Pros: Sharp
Cons: none
Sharpness: 10    Aberrations: 10    Bokeh: 9    Handling: 10    Value: 10    Camera Used: Pentax k-s2   

This is my new favorite lens. I shoot a lot of macros. My other macro lens is the 100mm version of this, which was my favorite lens.
Very sharp images!
Since it's shorter than the 100mm version, adding extension tubes makes the macro images even more magnified. That was just an added benefit. Bought it also for it's 50mm field view.

2 by Michael Piziak, on Flickr
New Member

Registered: March, 2020
Posts: 3
Review Date: April 2, 2020 Recommended | Price: $120.00 | Rating: 9 

Pros: Sharp, well builded, precise and smooth focus ring, cheap
Cons: Slow lens
Sharpness: 9    Aberrations: 9    Bokeh: 8    Handling: 10    Value: 10    Camera Used: Fujifilm X-E2, Fujifilm X-E3   

If it were a faster lens, it would undoubtedly be a 10 out of 10. Except for this, it has it all: excellent construction, sharpness, good focus control, contained size. To all of the above we must add versatility, such as a portrait lens on APS-C cameras.

Registered: January, 2019
Location: Geelong, Australia
Posts: 344
Review Date: January 4, 2020 Recommended | Price: $50.00 | Rating: 10 

Pros: Sharp, Macro, Solid build, small
Cons: heavy for its size

Using this lens for digital of film, it is fantastic.
Easily my favorite macro lens.

A+++ Highly recommended, if you get the chance to own one, i say do it.

Registered: July, 2013
Location: People's Republic of America
Posts: 9,400

1 user found this helpful
Review Date: December 31, 2019 Recommended | Rating: 10 

Pros: Sharp, cheap
Cons: f4 - but that is part of the design
Sharpness: 10    Aberrations: 10    Bokeh: 9    Handling: 10    Value: 10    Camera Used: K-50, K-S1, K10D   

How can you not give this lens a 10? Maybe if you think it's only an f4 lens - but you know that when you buy it... so no sense to complain about it. It's what makes this lens light and super sharp and well controlled even though it only has 4 elements. And having 4 elements means contrast and colors are just through the roof! It's as good, I think, as a lot of modern lenses in those aspects. And did I mention it's sharp?

Sharpness - great from wide open.

Handling - perfect, very smooth, very well built

Bokeh - not what this lens is for, but it's good enough - pretty discreet. It gets out of the way which is what it's supposed to do.

Aberrations - never seen any.

Rendering - great contrast and colors from wide open. Better images at f4 than my 50 1.7 and 50 1.4 lenses at f4!

It makes a great lens to walk around on a DSLR wide open. Macro lenses are supposed to be good for closeups and not so great at longer distances, but this lens can do it all!

Great for flowers
Edge of Pink by ChristianRock, on Flickr

Can anyone argue against the rendering?
A Well by ChristianRock, on Flickr

Covered Wall by ChristianRock, on Flickr

Great for stitching panoramas!
Norcross House Panorama by ChristianRock, on Flickr

More closeups
Bumblebees don't stop by ChristianRock, on Flickr

I guess this is a salvia by ChristianRock, on Flickr
Forum Member

Registered: August, 2013
Posts: 83
Review Date: May 22, 2019 Recommended | Price: $100.00 | Rating: 9 

Pros: Sharp
Cons: Manual
Sharpness: 9    Aberrations: 9    Bokeh: 8    Handling: 9    Value: 9    Camera Used: Pentax K1   

New Member

Registered: March, 2019
Posts: 47

1 user found this helpful
Review Date: April 22, 2019 Recommended | Price: $140.00 | Rating: 10 

Pros: Very Sharp, Beautiful color rendering, Great bokeh
Sharpness: 10    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 9    Camera Used: Pentax K-70   

I recently bought this lens and am very impressed with its qualities. I like the color reproduction most.

The lens is exceptionally light and comfortable, but at the same time it has a sturdy metal construction.

Very sharp even wide open.

The manual focus is very soft and precise.

Great lens for the minimal price. A must have lens for every macro photographer.

I'm not a professional photographer, so I'll let the pictures talk for themselves:
(All pictures below are taken at f/4, ISO-100, different speed)


Registered: May, 2014
Location: Linz
Posts: 2,757

1 user found this helpful
Review Date: June 16, 2018 Recommended | 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

2 users found this helpful
Review Date: October 30, 2017 Recommended | 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
Review Date: January 22, 2016 Recommended | 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

1 user found this helpful
Review Date: July 24, 2015 Recommended | 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
Review Date: April 19, 2015 Recommended | 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
Veteran Member

Registered: March, 2014
Location: Dallas, TX
Posts: 890

1 user found this helpful
Review Date: September 21, 2014 Recommended | 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
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