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SMC Pentax-M 100mm F4 Macro

Reviews Views Date of last review
33 199,306 Thu October 3, 2019
Recommended By Average Price Average User Rating
100% of reviewers $117.62 9.21
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
Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 1-15 of 33
Senior Member

Registered: November, 2018
Posts: 121
Lens Review Date: October 3, 2019 I can recommend this lens: Yes | Price: N/A | Rating: 10 

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

Site Supporter

Registered: June, 2013
Location: Utrecht
Posts: 51

1 user found this helpful
Lens Review Date: September 12, 2019 I can recommend this lens: Yes | Price: $60.00 | Rating: 9 

Pros: Look & feel, build quality, performance stopped down
Cons: Only 1:1, 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 1:1 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 1:1 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
Lens Review Date: June 14, 2018 I can recommend this lens: Yes | 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
Lens Review Date: October 18, 2017 I can recommend this lens: Yes | 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: 157

1 user found this helpful
Lens Review Date: October 31, 2016 I can recommend this lens: Yes | 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
Lens Review Date: March 9, 2016 I can recommend this lens: Yes | 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
Lens Review Date: March 8, 2016 I can recommend this lens: Yes | 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: 5,464

1 user found this helpful
Lens Review Date: December 21, 2015 I can recommend this lens: Yes | 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: 1,582

7 users found this helpful
Lens Review Date: June 30, 2015 I can recommend this lens: Yes | 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
Lens Review Date: July 4, 2014 I can recommend this lens: Yes | 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: 1,366

3 users found this helpful
Lens Review Date: April 3, 2014 I can recommend this lens: Yes | 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.
Veteran Member

Registered: November, 2010
Location: Hueytown, Alabama
Posts: 1,508

2 users found this helpful
Lens Review Date: September 29, 2013 I can recommend this lens: Yes | Price: N/A | Rating: 10 

Pros: Sharpness,Bokeh,Color and Contrast
Cons: None
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 10    Camera Used: K-5   

I have the Lester A DIne 105mm Macro and my old reliable M100 F/4 Macro when used with tubes is just as sharp if not sharper.

IMGP2943-M100F4 by crumlyt, on Flickr

IMGP2939-M100F4 by crumlyt, on Flickr

IMGP2931-M100F4 by crumlyt, on Flickr
New Member

Registered: July, 2013
Posts: 1

2 users found this helpful
Lens Review Date: July 2, 2013 I can recommend this lens: Yes | Price: $150.00 | Rating: 10 

Pros: Sharpness, bokeh, reliability
Cons: 1:2
Sharpness: 10    Aberrations: 8    Bokeh: 10    Handling: 10    Value: 9    Camera Used: K-30   

Amazing Pentax lens ! Great contrast, colors and beautiful bokeh. For me, definitely essential !

Have a look on my Pentax 100m f4 macro gallery for more exemples !
New Member

Registered: December, 2012
Posts: 7

2 users found this helpful
Lens Review Date: December 14, 2012 I can recommend this lens: Yes | Price: $99.00 | Rating: 10 

Pros: Sharp, Great Contrast, Beautiful Colors, Smooth Bokeh
Cons: Long Tube, only f4, needs a lot of light
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 10    Camera Used: Olympus OM-D E-M5   

I bought this lens a couple of weeks ago on ebay and am using it on my Olympus OM-D E-M5 with a K to MFT adapter, which adds about an inch to the length. Even with a battery grip it takes some practice to shoot handheld with this lens on the small camera, so often I use a monopod to steady it. But with the Olympus I get 5-way Image Stabilization and the photos coming out of this lens are just breathtaking. I have the Pentax-A 50 1.7 and this lens is sharper, with better colors. Love this lens. Wish it were faster and perhaps lighter, and I'll use some extension tubes to increase the magnification and may have to add a flash to make sure there is enough light. But its all worth it for the output.


Registered: August, 2012
Location: Queensland
Posts: 3,857

3 users found this helpful
Lens Review Date: August 17, 2012 I can recommend this lens: Yes | Price: $300.00 | Rating: 10 

Pros: Resolution and close detail
Cons: None
Sharpness: 10    Handling: 9    Value: 10    Camera Used: MX, K5   

What more can you ask of a lens? Macro that is usable if not the full x1. Great for portraits with full frame cameras, if the subject can handle the image sharpness. My lens, bought new, is over 40 years old, and I finally noticed a slight haze building inside the front lens. I could not see any affect on images, but it has now been sent for a professional overhaul so that it gives it's very best. That will cost me $120, so that must be some indication of the value this lens has to me. With this lens you have huge control, from near to semi telephoto with sharpness to sit with the best of them.
Edit June 2013: Apparently the 'haze' was likely a deterioration of the bond between two lenses, and replacements are not available. From what I understand, this is not uncommon with a lens like this. Regardless, the picture quality seems unaffected.
Edit 19/10/2015. The lens is f4, and magnifies half size. To complain that it isn't f2 and 1/1, is like complaining a sedan isn't a convertible. The lens should be judged on what it is, not what it isn't.
In regard to front-pair delamination, I have just acquired the SMC Tacumar version of this, and despite it being in near mint condition, the front pair also show early signs of delamination. While this seems a manufacturing anomaly, it doesn't seem to affect the resulting pictures.A lovely quality lens.
Add Review of SMC Pentax-M 100mm F4 Macro

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