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SMC Pentax-A 50mm F2.8 Macro Review RSS Feed

SMC Pentax-A 50mm F2.8 Macro

Reviews Views Date of last review
35 160,211 Sun August 1, 2021
Recommended By Average Price Average User Rating
100% of reviewers $143.55 9.60
SMC Pentax-A 50mm F2.8 Macro

The SMC Pentax-A 50mm F2.8 was the first Pentax macro lens to offer a fast aperture of F2.8. This lens supports auto metering and offers 1:2 (half life-size) reproduction.

The front element is sufficiently recessed that no lens hood is needed.

SMC Pentax-A 50mm F2.8 Macro
©, sharable with attribution
Image Format
Full-frame / 35mm film
Lens Mount
Pentax K
Aperture Ring
Yes (A setting)
Automatic, 6 blades
6 elements, 4 groups
Mount Variant
Check camera compatibility
Max. Aperture
Min. Aperture
Min. Focus
24 cm
Max. Magnification
Filter Size
49 mm
Internal Focus
Field of View (Diag. / Horiz.)

APS-C: 32 ° / 27 °
Full frame: 47 ° / 40 °
Not needed
Hard case HA-90
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Diam x Length
63 x 40 mm
220 g
Production Years
1984 to 1988
Engraved Name
smc PENTAX-A MACRO 1:2.8 50mm
Product Code
User reviews
Manual FocusAperture RingAutomatic ApertureFull-Frame SupportDiscontinued
Price History:

Add Review of SMC Pentax-A 50mm F2.8 Macro
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New Member

Registered: July, 2021
Posts: 1

1 user found this helpful
Lens Review Date: August 1, 2021 I can recommend this lens: Yes | Price: $120.00 | Rating: 9 

Pros: Light, SHARP, versatile, rendering
Cons: very little focus throw for normal (non macro) use
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 8    Value: 9    Camera Used: Pentax MX, Sony A6500   

One of my favorite lenses. Definitely my sharpest 50 at the moment. There is something in the rendering on the Sony that reminds me of shooting with film for some reason. Super versatile.

The sharpness is pretty incredible on this lens, even wide open at 2.8. It's probably sharper than my Pentax M 50/1.7 is when stopped down to 2.8. So even though this is a slower lens in general, I'd say that wide open it's VERY usable and I've done lots of shooting with it wide open. Very flat plane of focus too, so if you have work that requires that this is great.

This really is a versatile lens for all kinds of shooting, it just also focuses very close as well. I find that I like having the focus range between 45 and 30 cm (just a bit shorter than most 50's) even more than the super close 1:2 macro. I have a Vivitar 100mm macro that doesn't really do well shooting at non-macro distances, but that isn't true for this lens at all. Regular shooting is fantastic as well as close up.

The deeply recessed front element is nice, I don't have to worry about it getting scratched most of the time. And not using a UV filter probably helps with the sharpness.

I've paired it with an extension tube to get 1:1 macro and it's really impressive. I don't often use it that way, but it's great that it's an option. I've also tried it with the Vivitar 2x macro focusing teleconverter, and it was a very good pair, probably the best for actual macro. A bit of light loss, but the detail and sharpness is stunning.

My only complaint is that for normal shooting from 45cm to infinity, the focus throw is very short. Not unusable by any means but it can be quite touchy especially wide open.

Overall a really good purchase, I feel it was very worth the $120 I paid for it. If you're only carrying one lens and like getting in close, this one is hard to beat.
New Member

Registered: November, 2020
Posts: 5
Lens Review Date: March 17, 2021 I can recommend this lens: Yes | Price: $50.00 | Rating: 10 

Pros: Sharp, fast enough for Macro
Cons: Plastic
Sharpness: 10    Aberrations: 9    Bokeh: 8    Handling: 10    Value: 10    Camera Used: Fuji X-T1   

Amazingly sharp little lens. If I can only take one lens, I take this one. I use it to shoot everything from a few inches away to infinity. Well controlled flares and aberrations. When you nail focus with this lens, you've really nailed it. Love it... my favourite lens. BTW, I also own the 50mm f4 Macro and the 100mm f4 and love them both too - but this one is just a little more special.

New Member

Registered: May, 2020
Location: Evansville, IN
Posts: 12
Lens Review Date: October 1, 2020 I can recommend this lens: Yes | Price: $100.00 | Rating: 9 

Pros: Lightweight sharp fun to use
Cons: none
Sharpness: 9    Aberrations: 9    Handling: 8    Value: 10   

Fun to use macro lens that is versatile. At this focal length, yes one needs to be close to macro subject but even handheld, it's usable. On my copy, at least, the focus ring is quite light, relative to Pentax A 50 1.4 and 1.7 both, but is still easy to fine tune the focus. Very satisfying lens. The Pentax K3 meters reliably well with it on A mode.

Pic below unedited, uncropped, at f5.6, 1/250 ISO 100 handheld with Pentax in body stabilization on a fairly windy day, at that.
Site Supporter

Registered: October, 2008
Location: Vancouver, Canada
Posts: 7,338

4 users found this helpful
Lens Review Date: May 17, 2020 I can recommend this lens: Yes | Price: $153.00 | Rating: 10 

Pros: Speed, optics, handling, price.
Cons: Close working distance.
Camera Used: MZ-S   

The A50/2.8 Macro was released in 1984 and was a direct replacement for the M50/4 Macro. The A50/2.8 Macro remained in production until 1988 and was replaced by the optically different Auto-Focus version, the F50/2.8 Macro

Stellar optics! The A50/2.8 Macro also features floating lens elements.

Focal Length:
The 50mm focal length does not allow for much (miniscule is more like it) of a working distance when doing higher magnification macro work. I find this focal length much better for close-up work outdoors or just as a slower standard prime. Indoors when you can control the environment and maneuver the subject, then the 50mm focal length is OK. Itís good for copy or still life work, using a copy stand or tripod. For me this is what the 50mm macro is best suited and was originally designed for.

The A50/2.8 Macro is a well-built lens almost on par with any older Takumar/K/M series lens that I own. The aperture & focusing rings are also smooth when you turn them.

The A50/2.8 Macro weighs 220 grams and is a little bigger than a regular 50mm-55mm prime lens, but smaller and lighter than the F/FA versions that replaced it. So overall itís an easy lens to handhold and manual focusing. The A50/2.8 Macro also has an excellent distance/magnification scale, which you donít find on the auto focus versions.

The A50/2.8 Macro has a 49mm filter ring and requires no hood, due to the deeply recessed front element. The A50/2.8 Macro came with the HA-90 hard lens case and also fits nicely in the S70-70 soft case.

The A50/2.8 Macro is Pentaxís first fast 50mm macro and F/2.8 is now the standard. All thought if I use this lens as an all-purpose 50mm, then itís a bit on the slow side, kind of like the 40/2.8 pancake lens.

The A50/2.8 Macro has 0.5x magnification, which may be a negative for some people, but not for me. In the field Iíd never use this lens for 1.0x magnification, due to the extremely close working distance, so for me itís better to have a smaller/lighter lens thatís easier to carry or pack. I use the A50/2.8 Macro for close-up work outdoors and if needed just add the #3 Auto Extension tube for higher magnification work indoors.

The A50/2.8 Macro vs my other similar FL macro lenses:
I also own the K50/4 macro, this is how I rate the two against each other:

Optics: (tie)
Speed: A50/2.8, K50/4
Magnification: (tie)
Minimum Focusing Distance: (basically a tie, though the A50/2.8 is 1mm better)
Build: K50/4, A50/2.8 (A slight edge to the K Series lens)
Handling: (tie)

Overall, it comes down to the speed. The faster A50/2.8 Macro makes it a better all-around lens. I rated the K50/4 Macro as a 9.5 and will give the A50/2.8 Macro a 10.

The A50/2.8 Macro is another great Pentax macro lens and due to its fast speed, is a lens that I can also use as a regular 50mm prime on occasion. Itís also nice and small to travel with.

I bought my A50/2.8 Macro on eBay and itís in mint- condition. I paid $153USD, I purchased the lens case separately.

Sample shots taken with the A50/2.8 Macro. Photos are medium resolution scans from original slides and negatives.

Camera: MZ-S Film: Kodak Ektachrome 100 ISO: 100
(With #3 Auto Extension Tube)

Camera: MZ-S Film: Kodak Ektachrome 100 ISO: 100

Camera: MZ-S Film: Kodak Portra 400 ISO: 400

Camera: MZ-S Film: Kodak Portra 400 ISO: 400

Camera: MZ-S Film: Kodak Portra 400 ISO: 400

Registered: December, 2017
Posts: 426
Lens Review Date: June 21, 2019 I can recommend this lens: Yes | Price: $90.00 | Rating: 9 

Pros: Excellent built quality
Cons: Nothing I can think of.
Sharpness: 9    Aberrations: 9    Bokeh: 7    Handling: 9    Value: 10    Camera Used: K20d   

Today was my lucky day, i found the 50 mm Macro A and the 100 mm macro A together in a local ad site.

I was looking for either one of these to suit my object photography needs.
The 100/4 macro is well known to me. The 50 mm macro is a delight to use.
A versions are new to me and a much appreciated extra with the use of the K20d.

Pentax bodies with APS sensors are offered at rediciulous low prices.
Together with these macro lenses they give excellent quality.
What more do you need?
Junior Member

Registered: January, 2013
Location: Texas
Posts: 32
Lens Review Date: January 27, 2019 I can recommend this lens: Yes | Price: $180.00 | Rating: 10 

Pros: Size, Built Quality, Sharpness
Cons: Aperture ring
Sharpness: 9    Aberrations: 10    Bokeh: 9    Handling: 9    Value: 10    Camera Used: Pentax KP   

A long time ago, I used that lens with film cameras and my remembrance is that it was 'very good but not excellent'. Same for tests in magazines in the 1980's.
Because I like the light weight, the smooth focusing ring, and the 'built-in' hood, I decided to buy another one last year. I was very surprised by the high image quality; very similar to my legendary Nikon 55/2.8 Macro AIs (used on a Fuji X-T20).
The only thing I dislike is the plastic aperture ring (not used with Pentax DSLRs, but used when adapted on mirrorless cameras).
Be careful, many Pentax 'A' lenses have issues now, stiff focusing ring, stiff aperture ring, haze, separation of glued elements, etc.
Not more than other brands, but these lenses are 30+ years old.
Site Supporter

Registered: February, 2017
Posts: 1,334

2 users found this helpful
Lens Review Date: May 27, 2017 I can recommend this lens: Yes | Price: N/A | Rating: 10 

Pros: Close focus, Image Quality, Build Quality, Really useful Focal Length on film, FF and APSC
Cons: Rare possibly a bit pricey
Sharpness: 10    Aberrations: 9    Bokeh: 8    Handling: 10    Value: 9    Camera Used: K3, MX, KX   

I don't usually review a lens or camera unless I have owned it for some time, but in this case I must make an exception. This is probably the most useful lens anyone who shoots both film and digital could own. It is super sharp, not that I pixel peep, has nice contrast and colour reproduction. It focus usefully close, although not ideal for pure macro. It has a good general focal length for film or FF, and a nice short telephoto length for APSC. It handles well on both film and Pentax DSLRs due to the A lock. It has a reasonably bright max aperture. The only thing it lacks is AF, no big deal.
I bought my copy from Australia off Ebay. It cost me £102. I believe that was cheap as I have seen copies go for much more when they occasionally appear. I had been and still am in love with the DA50 f1.8, but was looking for a close up solution for that lens for walk around use. It was suggested that I get the Ltd 35 f2.8, but as I already had the 50 and the DA 35mm f2.4, both of which I like, the expense just did not seem justifiable.
I was looking on Ebay for the M 50mm f4, but the A 2.8, appeared in the search at what I consider to be a steal of a price.
It is a typically well made MF lens from the 80's with excellent handling characteristics, producing very good IQ. if you can find one get one as long as you can afford it. It balances nicely on any film or DSLR. It is small enough to fit in a jacket pocket so there is to reason to leave it behind when out and about. On my K3 this lens combined with a 28mm A f2.8, covers the vast majority of my needs. With my MX for film I will combine it with my 35mm f2.8 and 20mm f4.
Highly recommended!

Registered: April, 2009
Location: Madrid, Spain
Posts: 8,317

4 users found this helpful
Lens Review Date: February 15, 2017 I can recommend this lens: Yes | Price: $50.00 | Rating: 9 

Pros: Small, light but well built, excellent image quality
Cons: Bokeh can be harsh
Sharpness: 9    Aberrations: 10    Bokeh: 8    Handling: 10    Value: 10    Camera Used: K3 & various film SLRs, Fujifilm X-M1   

I bought this lens for a great price and in mint condition. They usually sell for much more than I paid.

It's small and light but well built, I'd say to the same standard as the DA limited series. It's not nearly as solid as Takumars or K or M series lenses but it is significantly better in this regard than the A 50mm f/1.7 or f/1.4.

Focusing is very smooth and the aperture ring clicks nicely making it very pleasurable to use.

Image quality is excellent. It's fairly sharp wide open, with a tiny bit of glow (visible only when pixel-peeping) but still very usable, and extremely sharp by f/4. Colour and contrast are fantastic, yielding a look comparable to modern digital-age lenses. Though I've used it mostly for it's close-focus abilities, it also makes a superb landscape lens. The bokeh can be harsh in some circumstances but that's hardly unusual for any lens. In most cases it's fairly smooth, especially when focusing close.

I have used this on film as well as digital but have not yet scanned any of the negatives so here are some examples from my K3 and Fujifilm X-M1. The first shot was taken wide open.

by Jonathan MacDonald, on Flickr

by Jonathan MacDonald, on Flickr

by Jonathan MacDonald, on Flickr

by Jonathan MacDonald, on Flickr

by Jonathan MacDonald, on Flickr

by Jonathan MacDonald, on Flickr

by Jonathan MacDonald, on Flickr

Yellow on yellow
by Jonathan MacDonald, on Flickr

by Jonathan MacDonald, on Flickr

Registered: February, 2010
Location: Northern Michigan
Posts: 4,981

3 users found this helpful
Lens Review Date: February 14, 2017 I can recommend this lens: Yes | Price: $125.00 | Rating: 10 

Pros: small, excellent build quality, sharp, very good rendering and color, very good contrast, no hood needed
Cons: none of any significance
Sharpness: 10    Aberrations: 10    Bokeh: 9    Handling: 10    Value: 10    Camera Used: Pentax K-5iis   

I already own the DFA 100 macro and the DA 35 macro, and I also own the K 50 f1.2 and the M 50 f1.7, so this lens faces stiff competition from my other glass and is very much a "speciality" lens. I bought it initially for aquarium photography, but it quickly shoved aside the M 50 f1.7 as my "take everywhere, use seldom" 50mm prime. It features more accurate color reproduction than my other two 50mm lenses, and the close-focus ability is an additional plus. While it may provide"only" 1:2 magnification, if the lens were 1:1 it would be significantly larger, which would nix one of its best attributes. For people who need 1:1 there are many others options available to fit that niche. For 50mm on APS-C or FF, 1:2 is usually enough.

Image-wise this lens produces sharp, contrasty images with very attractive colors. On an APS-C camera it's sharp edge to edge, at least from f4 (not sure about wide open, as I've never shot it wide-open). While this lens would not be the best choice as a portrait APS-C lens (the faster Pentax 50mm lenses, which often sell at lower prices, would obviously be preferable), for nature photography, both close-ups and landscapes, this lens is about as good as it gets at 50mm.

Build quality on the lens is superb. The lens itself (i.e., the glass elements) are very compact and are placed deep within the body of lens, which allows the outer barrel to function as a hood --- a very nice feature. Manual focusing is beautifully dampened. This is not a cheap plastic lens. It's from a different era, when quality counted for something and manufacturers took pride in their wares. There's real workmanship behind it, and it is a joy to own and use. Highly recommended to those who still appreciate old school values.

Some sample images:

New Member

Registered: June, 2016
Posts: 13

3 users found this helpful
Lens Review Date: December 16, 2016 I can recommend this lens: Yes | Price: $109.00 | Rating: 9 

Pros: Excellent build quality and all manual with the benefit of being an "A" series lens
Cons: none so far

Found this gem at Adorama used and snapped it up quick. Fits my K1 fine and works great-- this may be my 'go to' walk around lens!
will upload sample pics at another time after I do some more tests with this.
Loyal Site Supportaxian

Registered: September, 2013
Location: Texas
Posts: 501

4 users found this helpful
Lens Review Date: November 29, 2016 I can recommend this lens: Yes | Price: $180.00 | Rating: 10 

Pros: Incredible sharpness, Reasonable Bokeh, All-around usefulness.
Cons: None.

I have used numerous lenses. I do not give high scores easily. (I think a huge number of PF review scores are ridiculously inflated.) That being said, this lens is outstanding.

- Extreme resolving power: Out-resolves all other 50mm and 100mm macros I've tried. Much sharper than the limited's I've tried. The sharpness is not limited to the macro domain. It's just as sharp at 10 meters. Well matched with the Rear Converter-A 2Xs. In fact, it's sharper even with the aforementioned converter than the S-M-C tak or the m 100/4's without.

- Smooth, well damped focusing.
- Inset outer element means it effectively has a built in hood.
- Modest size. (But this comes at the cost of 1:1)

Image quality
- Very good contrast /acutance above f3.5
- Bokeh good for this class of lens on mid-distance subjects. Produces attractive portraits on full frame but you may have to soften in post if the sharpness is unflattering for your subject.
- Great color rendering.
- Focus 'snaps' well so it's a pleasure to manual focus through the OVF.

This lens has good enough bokeh and has reasonable enough speed to serve as an all-around 50 in most situations. It can produce some remarkable photos in full direct sunlight.

- Doesn't do 1:1 without an extension tube
- Manual focus only. (an issue for some, but not all users.)
Junior Member

Registered: March, 2016
Posts: 41

3 users found this helpful
Lens Review Date: March 20, 2016 I can recommend this lens: Yes | Price: $100.00 | Rating: 10 

Pros: Build quality & Optics.
Sharpness: 10    Aberrations: 10    Bokeh: 8    Handling: 9    Value: 10   

My most used lens, great value super to use.
Bokeh a little rough compared to the 1.4 M, and the
long focus throw not ideal for everything but it's perfect for what
it is and it's VERY useful.
Veteran Member

Registered: August, 2011
Location: Austin, Texas
Posts: 302

3 users found this helpful
Lens Review Date: January 9, 2015 I can recommend this lens: Yes | Price: $188.90 | Rating: 10 

Pros: Sharp, solid build, great bokeh, great color
Cons: Long throw manual focus
Sharpness: 10    Aberrations: 10    Bokeh: 10    Handling: 10    Value: 10    Camera Used: K-3   

Not an auto-focus lens, but who the $#!& cares! I use is for what it was made for...macro. Auto-focus can be a pain in the neck with macro shots and the focus-point aid in my K-3 is just perfect. I had been without a true macro for a while and was glad to pick this up...absolutely mint with caps, in the case. I will always have it with me for those close-detail nature shots.

Just for grins, I thought I'd try something with the SMC-A 50 Macro on my K-3 at ISO 51200...looks pretty good. You can easily see the dust particles. Hand held, 1/200 f-9.0 The left side bokeh is very smooth. Some purple fringing there, but it looks good (ISO 51200 after all)
PEG Moderator

Registered: August, 2008
Location: Highlands of Scotland
Posts: 53,208

8 users found this helpful
Lens Review Date: June 17, 2014 I can recommend this lens: Yes | Price: $250.00 | Rating: 9 

Pros: Very sharp
Cons: None
Sharpness: 10    Aberrations: 8    Bokeh: 9    Handling: 8    Value: 8    Camera Used: K20D   

A great small lens, very sharp indeed, will get only occasional use from me, but when required there is no real substitute for a real macro lens.

The linked images are the first few I took with this lens, to be perfectly honest it blew me away with the image quality.
Site Supporter

Registered: March, 2014
Posts: 38

3 users found this helpful
Lens Review Date: March 23, 2014 I can recommend this lens: Yes | Price: N/A | Rating: 10 

Pros: sharp, light, smooth
Cons: none
Sharpness: 10    Aberrations: 10    Bokeh: 9    Handling: 9    Value: 9    Camera Used: Pentax K10   

Just heaping more praise on this incredible lens. One of the very sharpest and best lenses I've ever owned.

If you find one in good condition, grab it and worry about the price later. You're not going to find one on Ebay for less than $250, so deal with it!
Add Review of SMC Pentax-A 50mm F2.8 Macro

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