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SMC Pentax-M 100mm F4 Macro Review RSS Feed

SMC Pentax-M 100mm F4 Macro

Reviews Views Date of last review
37 244,900 Tue January 17, 2023
Recommended By Average Price Average User Rating
97% of reviewers $116.47 9.08
SMC Pentax-M 100mm F4 Macro

SMC Pentax-M 100mm F4 Macro
SMC Pentax-M 100mm F4 Macro
SMC Pentax-M 100mm F4 Macro

This macro lens was also released with a dental scale. It is capable of 1:2 magnification.

SMC Pentax-M 100mm F4 Macro
©, sharable with attribution
Image Format
Full-frame / 35mm film
Lens Mount
Pentax K
Aperture Ring
Yes (no A setting)
Automatic, 6 blades
5 elements, 3 groups
Mount Variant
Check camera compatibility
Max. Aperture
Min. Aperture
Min. Focus
45 cm
Max. Magnification
Filter Size
49 mm
Internal Focus
Field of View (Diag. / Horiz.)

APS-C: 16 ° / 14 °
Full frame: 24 ° / 20 °
Not needed
Dedicated hard case
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Diam x Length
64.6 x 77.5 mm
355 g
Production Years
1977 to 1984
Engraved Name
smc PENTAX-M MACRO 1:4 100mm
Product Code
User reviews
Lens hood PH-R49 fits, but isnt necessary du to the recessed front element

This lens was also released with a dental scale as the smc PENTAX-M DENTAL MACRO 1:4 100mm

Manual FocusAperture RingFull-Frame SupportDiscontinued
Price History:

Add Review of SMC Pentax-M 100mm F4 Macro
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Closed Account

Registered: December, 2013
Location: West Virginia
Posts: 2,815

1 user found this helpful
Review Date: January 17, 2023 Recommended | Price: $100.00 | Rating: 9 

Pros: Sharpness & Price
Cons: Hard to find a copy that doesn't have lens separation
Sharpness: 10    Aberrations: 10    Bokeh: 9    Handling: 9    Value: 10    Camera Used: K-S2   

I have shot many macro shots with this lens and it is very good. Being an M manual lens, it is priced just right too!
I bought and sold a few of these, trying to find a mint copy; however, every copy that went through my hands had lens separation, so I just quit selling and buying them and kept my most recent purchase - which was bought from an estate sell from a guy that said his father was the only owner. He shined a light through it and couldn't find any defects; however, when I got it and put a light through it, it did have lens separation. However, the separation doesn't appear to affect my images.

14374656390_0bcf39d25f_o by Michael Piziak, on Flickr

Sunflowers in a Droplet by Michael Piziak, on Flickr

IMGP4399gimp3 by Michael Piziak, on Flickr
New Member

Registered: November, 2013
Posts: 14

1 user found this helpful
Review Date: August 29, 2022 Recommended | Price: $50.00 | Rating: 10 

Pros: very sharp lens
Cons: very small CAs
Sharpness: 10    Aberrations: 9    Bokeh: 8    Handling: 9    Value: 10    Camera Used: pentax k-5 k-x k200 k-s1 Fuji x-t100 x-e1   

I've both, the bellows version and the a.m. one with integrated extension tube.

An excellent vintage Pentax lens !

+++ no distorsion

++ razor sharp (85 LP/mm are a professional value with 24 MP sensor)

++ high contrast

++ nice color rendition

+ very small CAs sometimes visible by big magnification (have all macro lenses in bokeh)


I'm using an additional small macro tube of 12mm self made with an integrated achromate lens element of a binocular 8x30. The sharpness increases to 100 LP/mm and no more CAs are visible. Afterwards you'll get a 3.5/85 mm macro with 7/4 elements with extreme sharpness (ZEISS or LEICA level at a low price). Try it.


Try to get a Sioccore High Definition 1.8x top tele conveter (5/3 elements). With adapter rings from 52mm to 58mm you'll get a fantastic 4/180 mm macro rele lens with 10/6 elements (only for APSC !)

((lower judgements as 10/9 or 9/8 points have got perhaps a monday production)) ???

There is no difference in results between MINOLTA 4/100 and PENTAX 4/100 had demonstrated Stiftung Warentest, Germany (for all Pentax haters) only an expensive ZEISS macro lens or the famous TOKINA 2.5/90 are a few better.
New Member

Registered: June, 2020
Posts: 2
Review Date: September 7, 2021 Not Recommended | Price: $170.00 | Rating: 4 

Pros: Built to last, overall good contrast
Cons: f4 not so sharp, dull and washed colors in some situations, less contrast and resolution than M100/2.8 with macro tubes
Sharpness: 6    Aberrations: 9    Bokeh: 5    Handling: 8    Value: 5    Camera Used: Nikon Z5   

Generally, lens is very good, as all macro lenses are in that era. If someone wants to have it in its own collection - fine. Otherwise, no. It is hard to find good copy (without fungus or element separation).

Other, better options, are:
- Minolta MD 100/4 - better colors, better contrast wide open
- Tamron SP 90/2.5 - better resolution and bokeh
- Vivitar Auto Macro 90/2.8 - goes 1:1 without adapters

- Pentax M 100/2.8 (non macro) - comparable in contrast and resolution (using macro tubes) and even exceeds it from f5.6 on, and does not have problems with glass separation because it does not have glued elements. If someone already has this lens there is no point buying macro version because there is almost no difference.
New Member

Registered: January, 2021
Posts: 2

3 users found this helpful
Review Date: June 8, 2021 Recommended | Price: $116.00 | Rating: 9 

Pros: Handling, build quality, flat field sharpness.
Cons: None really. I'm ok that it is only f4.
Sharpness: 9    Aberrations: 9    Bokeh: 8    Handling: 9    Value: 9    Camera Used: Mostly Sony a7RII   

This is my first posting on this forum, so hope this is useful. I first purchased this 100mm Macro lens in my early 20s and always enjoyed the versatility. I think that it was one of the first telephoto lenses that I acquired at the time. Lately I've be rebuilding my original Pentax SLR system and added this lens (again) for a specific purpose. For digitising thousands of slides, similar to what Henrico has been doing in his post. The 100mm focal length is perfect - as I can work some distance from the slide or 35mm negative. Being a macro lens it has a very flat field and is simple use connected to an inexpensive bellows unit. I have two setups. The slide projector workflow is fast and yields good results, though the light source shows some vignetting. For the important slides or negatives I use a small darkroom enlarger as the light source. I'll attach an example.
On a film camera such as ME Super or MX, the handling brings back those early memories that I still remember. Feels so natural. On a Sony mirrorless the punch-in magnification makes focusing a breeze.


Registered: November, 2018
Posts: 583
Review Date: October 3, 2019 Recommended | Rating: 10 

Sharpness: 10    Aberrations: 10    Bokeh: 8    Handling: 10    Value: 10   

Loyal Site Supporter

Registered: June, 2013
Location: Utrecht
Posts: 253

1 user found this helpful
Review Date: September 12, 2019 Recommended | Price: $60.00 | Rating: 9 

Pros: Look & feel, build quality, performance stopped down
Cons: Only 1:2, bit soft wide open
Sharpness: 8    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 10    Camera Used: K1ii, K-01 and film   

Nice old school all manual 1:2 macro for a few bucks. Wide open a bit soft but stopped down very sharp. Contrast stays a little bit behind its modern siblings, but is easely adjustable in post. Be aware of lens separation and haze. My lens is very clear and clean. This very old optical formula seems to shine for bokeh and it delivers…

If you want a low budget versatile 100 mm this might be a good option. On full frame this is a nice portrait lens either. The 1:2 macro is a bonus.

I always was very happy with it. Now I own the DFA 100 mm macro this one became redundant. But it's a keeper, recommended!

See also:

Ideal for DSLR-scanning too:

New Member

Registered: October, 2009
Location: Millersville, MD
Posts: 7
Review Date: June 14, 2018 Recommended | Price: $75.00 | Rating: 10 

Pros: sharpness
Cons: coating under low light
Sharpness: 9    Aberrations: 8    Bokeh: 9    Handling: 10    Value: 10    Camera Used: K10 K5   

Not sure what all these numbers mean - what the heck is a "9" in sharpness relative to a "10"? . The lens is very sharp, compact and awesome. Its only defect is under low light, where images show considerably blue overtones when compared against my 50mm SMC-A. With good lighting, its colors are superb. I personally don't give a hoot for any automation, and this lens is a great value.
New Member

Registered: October, 2017
Posts: 2
Review Date: October 18, 2017 Recommended | Price: $45.00 | Rating: 9 

Pros: Macro, bokeh, color
Cons: long focus throw
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 9    Value: 10    Camera Used: K3, K1000   

This lens is one of my favorites. Got at a great price because of mark on front glass. I don't know how well it would do for human portraits, maybe on a full frame, but the bokeh is pleasant and adds a nice touch to small subjects. The f4 doesn't matter when you are outside, and the deeply set lens has prevented the need for a hood so far. I have a bit of a shake to my hands and am still able to get great images with this lens. Eventually would love to upgrade to dental version.
Senior Member

Registered: April, 2015
Posts: 158

1 user found this helpful
Review Date: October 31, 2016 Recommended | Price: $100.00 | Rating: 9 

Pros: Sharp and snappy iq. Lovely build quality
Cons: Bit slow? No 1:1
Sharpness: 10    Aberrations: 10    Bokeh: 8    Handling: 9    Value: 9    Camera Used: K5, k5 iis   

Lovely classic quality Pentax build. Just reassuring. Long focus throw. Iq is just top. Notch. It has five elements. Great!
Maybe f4 is a little slow, but if your eusing it for macro you are probably gonng to want to stop down anyway. On Aps c bodies it is not really a portrait lens Anyway, so it really is specialised to macro.
Aperture ring is a litle inconsistent,: 1 click from f4 to 5.6 and between f22 and 32, two clicks betwen all the rest! I have to remember when using it, no digital aperture read out of course!
Perhaps 1:1 would be nice to have, but extension tubes can b added. Whenever i reach for this lens and use it properly on a tripod i know the images are going to be about as great as it is possible to get,

Another thing to mensh, it has a lot of focus breathing, close up, focal kength is significantly bigger than far out, i havent measured it, but if it is 100 mm close up, it must be about 70 further out.
Forum Member

Registered: February, 2016
Location: Moab, Utah
Posts: 90

1 user found this helpful
Review Date: March 9, 2016 Recommended | Price: $190.00 | Rating: 10 

Pros: Sharpie, color rendering, long focus throw
Cons: no built in lens hood
Sharpness: 10    Aberrations: 10    Bokeh: 9    Handling: 10    Value: 10   

Ultra sharp lens from corner to corner. Beautiful color rendering to match other Pentax M and A series lenses. This lens is built like a tank, which I like for my macro. I use it with 10mm of extension tube for very close focusing and it works very well. Very small and feels great in your hand, like the other M series lenses, you cannot go wrong with Pentax SMC glass.
New Member

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

3 users found this helpful
Review Date: March 8, 2016 Recommended | Price: $100.00 | Rating: 10 

Pros: enormous sharp, build quality, flexible usage
Cons: none
Sharpness: 10    Aberrations: 10    Bokeh: 10    Handling: 10    Value: 10    Camera Used: Sony A7   

In my opinion the Pentax 4/100mm macro is the best manufactured lens in the M series. Its aperture ring remembers to the best manufactured Pentax lenses ever - The legendary "K" lenses ( only scribed with SMC) wich have helical mounts of brass on Aluminium.
When you have the 4/100mm macro, you don`t need a 85mm or a 100mm, it replaces them. Except you want to collect them all.
I use the 4/100mm for macro as well as for serious portrait photography. At wide open, you have a little smooth touch, wich is often an advantage in portraits, but there are little fringes too. Bokeh is fine.
At 8 and especially 11 it is great, great, great and extremely sharp - near, mid and far - on Sony A7, even without fringes.
I never saw such a corner to corner sharpness performance before and without image errors. Even a Nikkor 2,5/105mm doesn`t make a better job on the Sony A7 - it sucks in comparison with the mechanical quality of the M 4/100mm macro - sorry!
Avoid stepping down to 22 or even 32, it could happen, that you get little halo effects on, f.ex.
reflecting water drops in near distances.
Only frontal light could cause serious problems with low contrast on A7 - so use the original lens hood, to avoid flat colours.
A perfect lens for travel and trips, esecially in the mountains with their rich and interesting vegetation.
You will always enjoy the possibility to make wonderful selective enlargements from details or important parts in your pics. Or to replace a 150mm tele lens.
The Pentax M 4/100mm macro lens is definetly my favourite lens, especially on trips in nature!

I have to add some notes to this lens above:

Meanwhile I got another copy of the Pentax SMC M 100mm 4 and I claim, that it is much more better, than the lens I made the recommendation of in 2016.
Its hard to believe, that the optical performance could been achieved without
special lenses inside. Very good contrast and in comparison with the green star 300mm 4, there is almost no difference in sharpness, even wide open.
I would give this extraordinary lens at least 12 points! I think you know what I want to say.

Loyal Site Supporter

Registered: October, 2012
Location: Medina, OH
Posts: 7,224

1 user found this helpful
Review Date: December 21, 2015 Recommended | Price: $95.00 | Rating: 9 

Pros: Sharp! M build quality.
Cons: Heavy, well that is good and bad.
Sharpness: 10    Bokeh: 7    Handling: 10    Value: 10    Camera Used: K-3   

This lens appears to produce sharper, clearer images than any other lens in my cabinet, and that includes the legendary Pentax 50 mm f 2.8 macro, the three amigos (31, 42, 77), lots of legacy 50 and 55mms, several 135mms, and more. I shoot lots of flowers and insects, so this lens has been acquired during my off-season. I took a shot of a Lysol cleaning compound bottle across the room, and the type when enlarged is not only readable, but sharper than that some shot with any of my other lenses. I am looking forward to trying it out on bugs and flowers this coming spring and summer. Maybe I will also try it for portraiture before the flower season starts, but it may been a softening filter of some kind to keep from showing warts and all!

My copy, purchased on eBay from Japan, appears to be new with no dust or scratches, like it came right out of the box. (Just about everything I buy from Japan is like that.) With its metallic and heavy M build, the lens is a tactile delight with a reassuring heft to it that AF lens nowadays do not have. Aperture ring emits a nice clicking sound and stays firmly in place at your selected settings. Focussing ring has a well-damped long throw, and moving from closest to longest focus at infinity takes you through maybe 340 degrees. We'll have to wait and see how that weight works out for handheld focussing. I like the heavily recessed lens, which obviates any need for a hood, although I have fitted a hood anyway, which may need to be removed in use.

The lens is well suited to the K-3, and with this camera and lens you can do lots of resolving! This lens seems to list out on eBay at around $100, and at that price it is an excellent value.
Veteran Member

Registered: January, 2013
Location: Kansas City, KS
Posts: 1,612

7 users found this helpful
Review Date: June 30, 2015 Recommended | Price: $120.00 | Rating: 9 

Pros: Sharp!, 1:2, good focal length for bugs
Cons: long focus throw, not versatile
Sharpness: 10    Aberrations: 8    Bokeh: 9    Handling: 7    Value: 8    Camera Used: K-S2   

I bought this lens last fall on Ebay for about $120. Haven't done much with it. I used it for the Single in June 2015 challenge via PentaxForums.

Physically - It's an M lens. No surprises in build quality. It's pleasantly heavy, but not too heavy. The size is suitable. The focus throw is EXTREEEMELY long - it is a manual focus macro lens after all. The lens also extends massively (about twice its length) when it's at full magnification. If you're not paying attention, this can be surprisingly cumbersome.

In my estimation, it is very sharp in the center wide open (f/4), and sharp across the frame at f/5.6 - the aperture ring does have half-stops.

I didn't use it much for anything beyond EXTREME CLOSE-UPS (because macro), but the up-closeness of the images I created meant I was shooting for a sliver of a sliver of focus. It was very difficult for me to land a shot of a bug on a breezy branch until I wised up and started using burst-mode with a high frame-rate. With this method, I would shoot 3-7 shots or so and trust that, in one of them, the subject was somewhere within the sliver of focal range. It worked very well and I ended up getting the shots I wanted.

I didn't notice any chromatic aberration or fringing, but I did nothing to encourage these types of defects to reveal themselves. The color rendition was excellent and true-to-life, although I did do some standard boosting of vibrance/saturation as I would do with any RAW file, and that seemed to improve the images (although that was probably most likely due to the subject matter - little insects and flowers and things).

The bokeh was very fine, especially when the subject was extremely up-close, obviously, as per rules of bokeh-ing.

I've found macro subjects are probably not really my "thing", at least not right now. I might be able to get more "into it" if I upped my flash game and didn't have to fuss over balancing the ambient light with a less-than-generous aperture, camera shake at 100mm, and the damn wind/moving subjects...

Ultimately, macro was fun for a month, and the lens is a treasure with a very specific skill set. It's not a good daily driver for my needs. I found 100mm to be an awkward (too long/too short) focal length, and the miles-long focus throw had me sighing sometimes. Trying to land my subject in the paper-thin focal range was very tedious. Ultimately, for macro shots, I would probably rather use my MX-1 and its 1-cm focusing abilities (because of its bright aperture and fast auto-focus), although being able to "stay back" with the 100mm focal length was appreciated for some skittish subjects.

Here's a link to my Flickr album with all of my images from this lens: CLICK HERE
Veteran Member

Registered: April, 2013
Location: the Netherlands
Posts: 2,444
Review Date: July 4, 2014 Recommended | Price: $120.00 | Rating: 9 

Pros: Sharpness, size, weight, nice manual focus, cheap
Cons: only f/4, only 1:2

It is a decent macro lens I say specially for the price, super sharp right from wide open. with very nice colors rendition as I understand.
The build quality is pretty darn good, it's very light and small, I love the feel of handling it. It has a very long focus throw which isn't surprising because of macro ability.
When I was buying it, I felt that the focus ring is getting stiffer as I rotate it towards macro side, and thought it's not good, but after handling it, I think it should be this way, so you can focus very slightly in macro end of focus.

What it lacks is the more magnification, and It's f/4, so the viewfinder is dimmer in low light, that makes focusing harder. and well a f/2.8 could make better DoF control in longer distances also.

And after using it for one month, I love the 100mm FL for normal usage too!

Registered: December, 2012
Location: Seattle, WA USA
Posts: 1,753

3 users found this helpful
Review Date: April 3, 2014 Recommended | Price: $120.00 | Rating: 9 

Pros: Build Quality, Sharpness, Bokah, Macro
Cons: could a stop faster, I suppose
Sharpness: 9    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 8    Camera Used: K5ii and MX (film)   

I've had this lens for a year and thought I should submit my review.

So, first of all, it's beautiful and feels perfect in your hand. Focus is like...I don't know winding a really good watch or spinning a just serviced Campy or Chris King hub, if you're a cyclist. I wish every focus ring felt like this. It is long throw for the macro, so that's good when you need it if you're trying to photograph a moving object and are at the wrong end of the focus ring, it's takes a little while. Once you're in the ballpark, no worries.

I really like the Macro, (1:2), I haven't tried it with extension tubes. At 1:2 and 100mm, it's really practical, great super close focus pictures with amazing detail, color blur. I really enjoy Macro photography, but my standards might be slightly different than yours. I think it's great.

Non-macro closeish focus photography gives you sublime bokah. Any time you've got good separation between fore and background, it's right there with my 50/1.4 for beautiful bokah. I've never seen any with it that I didn't like, which is saying something.

I've also taken sunset pictures and general long walk-around and it's a great lens, though it's a strange walk-around FL.

All that said, this is probably my least used lens. I pull it out for a macro photo for a web image or something and occasionally shoot with it just because. I've been meaning to try it for band photography. f4 is not really fast enough, but here's the thing, the difference in sharpness between F4 and F5.6 is very minimal and between 5.6 and 11, almost non-existent. So, it's a very clear image at f4 and it might work on those occasions when I'm in the back of the room.

Would I buy it again? Hard to say. I want a lens with macro capabilities and I doubt I'll do better than this for $100. But if I end up with another lens that happens to do macro as well as a secondary function, I might. As much as I love it as an "other" lens 100/4 is an odd combination that keeps me from reaching for it as often as I might if it was either a little shorter, twice as long and/or a stop or two faster.

If it fills a hole in your kit and it sounds like a good choice for you, you won't be disappointed.

Here's my Flickr set for it.
Add Review of SMC Pentax-M 100mm F4 Macro

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