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SMC Pentax-A 645 120mm F4 Macro Review RSS Feed

SMC Pentax-A 645 120mm F4 Macro

Reviews Views Date of last review
19 99,340 Tue October 4, 2022
Recommended By Average Price Average User Rating
100% of reviewers $227.37 9.68
SMC Pentax-A 645 120mm F4 Macro


Manual focus macro lens. The lens is also a fine short tele/portrait lens.

smc Pentax-A 645 120mm F4 MACRO
©, sharable with attribution
Image Format
645 film
Lens Mount
Pentax 645
Aperture Ring
Yes (A setting)
Automatic, 8 blades
9 elements, 7 groups
Mount Variant
645 A
Check camera compatibility
Max. Aperture
Min. Aperture
Min. Focus
39 cm
Max. Magnification
Filter Size
67 mm
Internal Focus
Field of View (Diag. / Horiz.)

645 Digital: 26 ° / 21 °
645 Film: 32.5 ° / 26 °
MH-RA 67mm screw-in
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Diam x Length
78.5 x 110 mm (3 x 4.3 in.)
695 g (w/o attachments) (24.5 oz.)
Production Years
Engraved Name
smc PENTAX-A 645 MACRO 1:4 120mm
User reviews
Manual FocusAperture RingAutomatic ApertureMedium-Format SupportAdapter needed for DSLRsDiscontinued
Price History:

Add Review of SMC Pentax-A 645 120mm F4 Macro
Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 1-15 of 19
New Member

Registered: December, 2021
Location: Pacific Northwest
Posts: 3
Review Date: October 4, 2022 Recommended | Price: $137.99 | Rating: 9 

Pros: 1:1, bokeh, color rendition
Cons: Size, weight
Sharpness: 9    Aberrations: 10    Bokeh: 9    Handling: 9    Value: 10    Camera Used: Pentax 645N   

Cheap nowadays for what you get, which is a giant hulking beast of a lens. Has scanning applications with modern DSLR scanning. It might be a sleeper for the best bokeh on the system (not including the adapted 105 2.4), but unfortunately it's too large to take out and use for many applications, and it'll mostly be relegated to tripod use, so I haven't shot it as much as my other lenses. Foreground bokeh is nice which with macro can be relevant. Of course minimum focusing distance is excellent. Focus throw is extremely far but otherwise handling is good for what it is. Color rendition in my limited shoots with it seems to be particularly good, but it's a limited sample size.
Contrast and flare control is all great as you'd expect. Can't comment on aberrations.

New Member

Registered: January, 2021
Location: Pianezza (Torino -Italy)
Posts: 23

1 user found this helpful
Review Date: January 27, 2022 Recommended | Price: $150.00 | Rating: 10 

Pros: Sharp
Cons: Nothing
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 10    Camera Used: Pentax 645D   

Manual focus stacking (10 frames)
Loyal Site Supporter

Registered: October, 2018
Location: Quebec City, Quebec
Posts: 6,212
Review Date: July 25, 2020 Recommended | Price: $175.00 | Rating: 10 

Pros: Very sharp macro lens. Solid build. Has f/32.
Cons: Heavy.
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 9    Value: 10    Camera Used: 645Z, 645 Auto Bellows   

A 120 mm on 645 Auto Bellows

I have the FA 120 mm f/4 version too. This A version produces very detailed images and the long-throw helicoid helps attain critical focus at high magnifications, whether the lens is mounted on the 645 Auto Bellows or not. The picture of blackberries was taken with the lens alone @ f/11, its optimum aperture. The strawberries, cherries and broccoli images below were taken with the help of the 645 Auto Bellows.

This lens reveals a world of wonders to explore.

New Member

Registered: July, 2018
Posts: 4
Review Date: July 9, 2018 Recommended | Rating: 10 

Sharpness: 10    Aberrations: 10    Bokeh: 10    Handling: 10    Value: 10    Camera Used: Canon EOS 5DS R, 5Diii, 1DSii   

I am an architectural photographer using Canon 5DS R, 5D iii and 1DSii with Pentax 645 lens with Mirex adapter.

Pentax 645 A 120mm macro

Tested at f11, after f16 you get diffraction. Sharpness is excellent!! Hardly any distortion. Shift up to 12mm.

Did a duo row gigapan using the full image circle:

And a close up of coffee abstractions and tilting :

Old lenses like this give you that analogue film like feeling, detail yet not sharp sharp. Love it.
Site Supporter

Registered: February, 2018
Location: NoVA
Posts: 635

1 user found this helpful
Review Date: June 12, 2018 Recommended | Price: $139.00 | Rating: 10 

Pros: Critically sharp, even wide open
Cons: Bokeh is so-so
Sharpness: 10    Aberrations: 10    Bokeh: 5    Handling: 10    Value: 10    Camera Used: 645z   

I can't even believe this lens only cost me $139, on ebay.

I've read it's not quite as good as the 90, and that it's not as good at distance. I don't have the 90 to compare it to, but my test was at distance, so at least I can explore that. There is already an excellent review of the autofocus FA version of this lens here, which praised it highly, so I won't attempt to test it in the macro range. But I wanted to know how it would do as a general-purpose lens.

Here's my test scene at f/11:

Even this image, most of which depends on the depth of field, looks sharp. The bark of the River Birch at left is quite sharp, and the background is reasonably sharp. This lens can definitely make a 16x20 that never undermines the illusion of endless detail.

I had so much trouble trying to decide what the optimal aperture was, that I decided to show all of them.

I'm only showing center crops, simply because I could tell the difference between the centers and the corners. Okay, I'll show one corner. Here's the lower right corner at f/11 and 1:1:

There is some motion--this was a 1/3-second exposure. But the image is sharp. Remember, 1:1 at 100 pixels/inch of most monitors is part of a print seven feet wide.

So, back to the center. Here's the center of the frame at 1:1, shot at f/4:

Not too shabby, for sure. Sharper than the A* 300.

The bokeh isn't much to write home about, though, so I'm not thinking this is a superlative portrait lens. At wide apertures, you'll be adding gaussian blur to the image to make it tolerable for a portrait of a sitter who will actually expect the image to be flattering, but even at wide apertures, the background will be distracting. But that's not what this lens is for.

Here it is at f/5.6:

In the focus plane, I'm not absolutely sure I can tell these apart.

And at f/8:

F/5.6 actually looks a bit better than f/8. Huh?


Worse still.



It's bee a long time since I looked at an SLR lens that was actually at its best wide open. In fact, I'm not sure I ever have. This may be the first truly diffraction-limited medium-format lens I've ever handled. With this lens, you use the widest aperture that provides the necessary depth of field.

Let's look at that lower right corner again. Here's f/11 again:

And here's the same corner at f/4:

Yup, even the corner is sharpest wide open, as long as it's in focus.

Simply amazing. Even the superb 55/2.8 got sharpened up enough down to f/11 to overcome diffraction.

Oh, you can bet this one's going to Alaska. This will be one of my most used lenses. Now, I have to wonder if this lens with the 1.4 converter will be sharper than the 200/4, which, stopped down a bit, is no slouch.

I'm going to have to adapt this lens to my Canon and put it up against my 70-200f/4L (which I think it will beat) and the 50mm Compact Macro, which is one of the sharpest lenses in the Canon line.

Rick "this one's dangerously sharp" Denney
New Member

Registered: August, 2017
Posts: 5
Review Date: September 1, 2017 Recommended | Price: $180.00 | Rating: 9 

Pros: Good quality
Sharpness: 9    Aberrations: 9    Bokeh: 9    Handling: 9    Value: 9    Camera Used: 645D   

Actually, for a macro lens it doesn't need the auto focus, however, instead it should be sharp and get a very close focus distance. It works and the detail shown is excellent and ease to handle without any sudden slippage during photo taking. The resistance of the focal ring is good and ease to handle. But...... why there is no hood is included ..?
Loyal Site Supporter

Registered: October, 2012
Location: Medina, OH
Posts: 7,219

1 user found this helpful
Review Date: June 19, 2017 Recommended | Price: $126.00 | Rating: 10 

Pros: Sharpness, close (1:1 macro), color rendering
Cons: Lots of flare on the K-1 with adapter.

I bought this lens from Keh for only $126 including handling. Keh graded it UGLY, but the lens I received was Excellent ++, just missing the caps, but hardly a mark or blemish of any kind--gotta love Keh's grading system. I am primarily a gardener and flower photographer (amateur only). This lens is absolutely fantastic for what I do. I am not sure what the medium format 120mm field of view becomes on the K-1 full-frame camera, but it works for me in the flower garden, no problem. I get fantastically sharp well-rendered photos with loads of color fidelity. I am accustomed to doing fairly minimal post processing (cropping, lightening, adding clarity, etc.) but I am getting an amazing number of photos that cannot be improved upon right out of the box, so to say.

As for the macro feature, I do not do a great deal of macro work, but it is nice to have 1:1 macro capabilities right at my finger tips when needed, but the close feature aspect is what is really great for flowers. The sharpness of the lens lets you take a broad general photo, and then crop down to what you want to feature/keep.

For some people, the weight of the lens might be a problem, but not for me. I am a fairly big guy, and used to do weddings with a Mamiya RB67 hanging around my neck, so a Pentax K-1 and MF lens is no burden. As for weight on the mount, I think the A120mm macro is okay, but I generally steady the camera with a hand beneath the lens to take some of the load off the mount. Tripod is a nice option for those who have the time, energy, and interest but my cheap Chinese adapter did not come with a mount, so mounting the camera itself would not relieve the strain on the K mount.

I focus manually with any lens that conveniently provides that capability, so manual focus is also not a problem. For macro use particularly I suspect that most folks use manual focus even when AF is available. As a macro lens, the 645 120mm/4.0 has a very long throw at the macro end of the line as expected, but a much shorter throw at the distance end of the line. In other words, it is set up for macro work. For landscape or any longer use, it would be nice to have longer throw to the focus ring when turning to the right because you move in and out of focus pretty quickly on the long end. I focus using the viewfinder and looking for the beep and little green light in the viewfinder, but it is easy to turn past it and have to turn back to find it and go back and forth to get it to settle to a solid unblinking focus light. You can try live view focussing but with the weight of the lens and camera that becomes problematic unless you are on tripod where it ought to work pretty well.

The worst thing about the lens (when used on Pentax K-1 with adapter) is flare, particularly if lens is pointed upward or includes part of the sky. This big lens captures a lot of light, and light has to have somewhere to go. Check to make sure your adapter has black matte color/coating and texture to eliminate as much extraneous light as possible from bouncing around inside. A good hood would likely eliminate this problem, and I have eliminated it by using a longish black construction paper hood, which of course is an awkward and temporary solution, and sometimes the faux hood falls off right in the middle of a shot. If you are using the lens in a professional context this solution would just look too shoddy but us amateurs really don't care about that. My other solution is to hold my large black cavalry hat above the lens, and that will do the flare-reduction job for anyone who does not find the K-1 and large lens too heavy for one hand operation! I am looking for a longish hood that will not vignette, but I suspect this will be long job, and I expect to go through a few more sheets of construction paper before finding what I need. For most of my work with lens pointed downward or parallel to the ground and not toward the sky there is no flare. As stated, I am using this lens with adapter on K-1, and suspect that the flare problem does not occur when used on native 645 mount, but I have not tried it on my 645 and 645N cameras--well I have tried it but not have sent the film off for development yet.

For macro and flower photographers particularly I really recommend this lens for use as an adapted lens on the K-1 if the disadvantages I have mentioned do not bother you. To me the quality of the work it produces and the cost-value equation are excellent. If you can find one for somewhere between $100 and $300, I would say to grab it fast before it goes away.
Loyal Site Supporter

Registered: January, 2009
Location: East Bay Area, CA
Posts: 6,568

6 users found this helpful
Review Date: October 3, 2013 Recommended | Price: $325.00 | Rating: 9 

Pros: sharp! smooth focusing. metal construction[im
Cons: heavy
Sharpness: 9    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 9    Camera Used: 645D   

OK, I admit I am not really a macro nor portrait photographer, so my purchase of this lens(the SMC Pentax-A version) was primarily for landscapes. I have an array of primes for the 645D ranging from 25mm to 150mm and this lens fills the gap between my 67 105 and my FA-150.

For landscape shooting, I always manual focus, so any lens with AF is lost on me. Moreover, I almost always use M-mode, so even the A- capabilities of this lens are nice, but I can survive just fine clicking the aperture ring instead.

The first thing I notice about this lens over all other 645 lenses in my kit is the amazingly smooth and well damped focus ring. The turning action is a pleasure, not unlike some of the great all metal K-mount Takumars. We manual focusers do so dislike the short throw on the modern AF lenses that make it so hard to accurately focus manually. This lens is pure pleasure in the hands. The weight is fairly substantial, certainly heavier than my FA 150 which is plasticky by comparison.

Image quality is outstanding and CA's are very well controlled in this lens. I have a few lenses in my kit that need an automatic fringe adjustment right out of the gate. but this lens manages well in high contrast areas. Sharpness and contrast are great and no surprise from a well designed macro lens. The front element is inset to create a natural hood and I always add an additional rubber hood to mine to eliminate oblique light on the front element.

Not much more to say really, so here are a couple of pics. These are processed, of course.

this one uses focus bracketing
New Member

Registered: December, 2012
Posts: 8
Review Date: April 18, 2013 Recommended | Price: $300.00 | Rating: 10 

Pros: Well built, weight, size, sharp, natural color
Cons: none
Sharpness: 10    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 9    Camera Used: K-5IIs   

I used this on my K-5 with a 645 adapter and I believe this focal isn't 120 anymore but really doesn't matter to me.

I take this lens out a lot and take whatever I find right and it delivers a lot of fun and great photos as all other 645 lenses do. I have a 75 f2.8/35f3.5.

I like to mention that, may be because of the weight of this lens balance so well with my K-5 which gives a very confidence pressing on the shutter resulting ultra steady photo capture.

Here is a handheld snapshot by a 50s old man, me, 1/5 cropped from the original photo. It is amazing.

New Member

Registered: October, 2012
Location: Pamulang, Tangerang
Posts: 1

4 users found this helpful
Review Date: October 1, 2012 Recommended | Price: $290.00 | Rating: 10 

Pros: Truly sharp!
Cons: almost none to me
Sharpness: 9    Aberrations: 8    Bokeh: 10    Handling: 7    Value: 9    Camera Used: D7000   

Well, every good and other considered things already mentioned here & there. So lets the picture tells..
Conclusion: as macro shooter.. ooh so loving it..
Veteran Member

Registered: December, 2008
Location: USA and Europe
Posts: 585

3 users found this helpful
Review Date: April 1, 2012 Recommended | Price: $250.00 | Rating: 10 

Pros: SHARP, good color, smooth focusing, comfortably heavy
Cons: none
Sharpness: 10    Aberrations: 8    Bokeh: 8    Handling: 10    Value: 10    Camera Used: K-5, K-20D   

I've been shooting with lots (hundreds) of Pentax, Nikon, Canon, Minolta, Sigma, Tamron, Vivitar, etc. lenses and I know well what "perfectly sharp" means. The sharpest MACRO lenses I've ever used were Nikon 200/4 AF-D, Nikon 105/2.8 AF-D, Kilfitt Makro-Kilar 90/2.9.
The Pentax 645 A* 120/4 is in the same league. The resolving power is just amazing.
Good, natural color reproduction.
Quite heavy , which is always a plus, adds a lot of "natural" image stabilization.
SMC (non APO/ED) glass does produce some CA, but for such focal length it's not very prominent.

Overall I'm very happy with this lens performance and would highly recommend it .
Veteran Member

Registered: February, 2011
Posts: 573
Review Date: September 4, 2011 Recommended | Price: $400.00 | Rating: 10 

Pros: Very sharp
Cons: Really long at 1:1
Sharpness: 10    Aberrations: 10    Bokeh: 10    Handling: 7    Value: 10   

I bought this for a Pentax 645D. This is an excellent medium telephoto for this camera. It has the added benefit of being a great macro lens. Because it is a macro lens, the helicoid focusing can be a little too crude for far subjects and the DoF scale is not very helpful either, but I have not found this hard to focus on the 645D ground glass. The lens is really, really long when focused at 1:1--perfect if you have lens envy. Having the extra close focus distance is also great for portraiture as you really don't run into a minimum distance stop which can happen with other medium-format short telephotos.

Registered: February, 2010
Location: Eerbeek
Posts: 1,821

1 user found this helpful
Review Date: November 11, 2010 Recommended | Price: $250.00 | Rating: 10 

Pros: incredibly sharp
Cons: hood hard to come by
Sharpness: 10    Aberrations: 10    Bokeh: 9    Handling: 9    Value: 10    Camera Used: 2 years   

This lens came with a 645N body, so the price is approximate. I did not think I would have use for a Macro lens, as that's not my thing, but this lens, when tested, produced such incredibly detailed photos that I decided not to part from it. It definitely has the wow factor. The initial pictures were taken at f. 16. I have not deliberately tested it at all apertures but I would not hesitate to use it from wide open to f. 32.

It is heavy and bulky, relatively speaking, but not too much. The metal screw-in lens hood is expensive and when attached it makes the lens very long.
My only problem with this lens is that it's too close to my LS 4/135mm and FA 2.8/150mm in focal length, while being different from both. I have used it frequently on a K-x where it performs well, via the adapter, in Av mode.

Manual focusing with this lens is probably want you want in most circumstances anyway, and a dedicated manual focus lens like this one is therefore preferable, although you do not get the exif data printed on film or in file.
Site Supporter

Registered: December, 2008
Location: NJ, USA
Posts: 428
Review Date: May 22, 2010 Recommended | Price: $200.00 | Rating: 10 

Pros: Sharp,
Cons: heavy

I bought this used from KEH. Love the lens. It is a great macro and portrait lens and my best 645 portraits are taken with this lens.

I will buy an adaptor and use it with digital as my macro.

Build and focus ring are great.

It is heavy.
Veteran Member

Registered: March, 2008
Location: Hogtown, ON, Canada
Posts: 329
Review Date: September 1, 2009 Recommended | Rating: 10 

Pros: Extremely sharp, close focuign
Cons: none

Mine was bought new in 1990.
It replaced the 120CF Makro Planar in studio for 120 shooting. My clients and the prepress service cannot tell the difference beside 645 and 66 chrome size.

It is so good that I am still using it today on my Dslr's. I didn't need AF so I stayed with the A version.

This lens along with the FA300EDIF dispel the myth that 120 camera lens are inferior to 35mm counterparts because of the larger chromes makes up for any shortcoming.
Add Review of SMC Pentax-A 645 120mm F4 Macro

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