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SMC Pentax-A 50mm F1.7 Review RSS Feed

SMC Pentax-A 50mm F1.7

Reviews Views Date of last review
142 559,949 Thu November 23, 2023
Recommended By Average Price Average User Rating
99% of reviewers $59.22 8.91
SMC Pentax-A 50mm F1.7

SMC Pentax-A 50mm F1.7
SMC Pentax-A 50mm F1.7
SMC Pentax-A 50mm F1.7

The SMC Pentax-A 50mm F1.7 is a fast standard lens shipped with many 1980's Pentax bodies. It supports all exposure modes.

SMC Pentax-A 50mm F1.7
©, sharable with attribution
Image Format
Full-frame / 35mm film
Lens Mount
Pentax K
Aperture Ring
Yes (A setting)
Automatic, 6 blades
6 elements, 5 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: 32 ° / 27 °
Full frame: 47 ° / 40 °
Various types
Hard case HA-90B
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Diam x Length
63 x 31 mm
165 g
Production Years
1984 to 1989
Engraved Name
smc PENTAX-A 1:1.7 50mm
Product Code
User reviews
Lens was sold without hood. Several hoods will fit like PH-S49 (50mm) and screw-in type metal and folding rubber hoods
Manual FocusAperture RingAutomatic ApertureFull-Frame SupportDiscontinued
Price History:

Add Review of SMC Pentax-A 50mm F1.7
Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 1-15 of 142
New Member

Registered: February, 2019
Posts: 15
Review Date: November 23, 2023 Recommended | Rating: 8 

Pros: Nice for close up and middle distance
Cons: Struggles at infinity and too much plastic
Sharpness: 8    Aberrations: 8    Bokeh: 6    Handling: 6    Value: 8    Camera Used: Film and digital full-frame   

Not bad, really. A little compact gem of a 50mm lens.

On film cameras - remembering that when you rate a lens on a digital sensor and processor you are not rating only the lens - this is a pretty fine lens. It does everything you'd expect of a decent 50mm lens to a very good standard. About f4 to f11 is best for all-around performance (I never believe anyone who says a prime lens is excellent "wide open" unless they are only taking close up images) and this lens is not so bad at the aperture extremes if you have a clean glass version.

Up close is good and up to middle distance is as fine. But if you want sharp images at infinity this can fall a little short in some conditions, but it's never awful. Nice coatings and low flare. Ordinary background bokeh and no CA fringing except at wide open apertures shooting in longer distance situations. Nice colours and nice contrast.

Handling is not wonderful. The only thing I really don't like about it is that it has a lot of soft - and old - plastic on its design. The aperture ring can get dry and stiff and jerky, and can easily snap in servicing. It feels cheap and cheerful and age has deteriorated the plastic parts. It's the same with all A series lenses. Compare it to the M Series F1.7 version and there is no competition to be made; it's the M Series every time.

A lovely cheap and cheerful 50mm lens from the metal to plastic era.
New Member

Registered: November, 2019
Posts: 1
Review Date: March 21, 2023 Recommended | Price: $48.00 | Rating: 9 

Pros: Sharp. Compact.
Cons: None
Sharpness: 10    Aberrations: 8    Bokeh: 9    Handling: 10    Value: 10    Camera Used: Pentax K-3, K-1.   

An excellent lens, which performs brilliantly as a 'nifty-fifty' on my K-1 and as a short, portrait, telephoto on my K-3.

Compact and well-made it is a delight to use on the move; more frequently adorning my K-1 than the capable, but heavy, Samyang 50mm f1.4 which I specifically bought for the K-1.

On those rare occasions that I've used it on a film camera (Ricoh XR-1S) it has produced exceptionally good results, though in truth, not ultimately quite as good as those produced by the Carl Zeiss Planar 50/1.7, that originally came with a first generation Contax RTS I owned, which now sits on my Contax 139Q.
Senior Member

Registered: June, 2020
Location: Guangdong
Posts: 118
Review Date: February 14, 2023 Recommended | Price: $80.00 | Rating: 9 

Pros: saturated color, light-weighted, amazing anti flare ability, beautiful bokeh
Cons: aperture ring prone to getting stuck, aberrations
Sharpness: 9    Aberrations: 8    Bokeh: 9    Handling: 8    Value: 8    Camera Used: K-50   

This is my first Pentax lens apart from the 18-55mm kit. I enjoy this lens's compact design and saturated color. It has excellent sharpness at F2.0. It loses just tiny contrast in backlight conditions and that's really helpful when you do portraits. When you shoot at 45cm (min. focus distance), it brings passable images. Tip: this lens's aperture is prone to getting stuck and I strongly suggest keeping it to the A position all the time.

p.s. I was looking for a 50mm lens when I started to get to know Pentax (and photography) because I heard this is a pervasive choice for most photography beginners...and soon after my purchase, I learned about equivalent focal length lol. But ever since then, this lens inspire me to collect more full-frame lenses, wishing to lever a big step when I have my K-50 upgraded!
New Member

Registered: October, 2021
Location: Visby, Gotland
Posts: 18
Review Date: October 8, 2021 Recommended | Price: $20.00 | Rating: 9 

Pros: Small, easy to handle, quality
Cons: A little soft stopped down, no AF.
Sharpness: 9    Aberrations: 9    Bokeh: 9    Handling: 8    Value: 10    Camera Used: K-x. K-5   

A nice and easy to handle prime. Build quality and optics are good, and the only real drawback is that it has no AF.
I have had several Pentax 50mm primes and at times I actually find the ”cheaper” 1:2 to be sharper than the 1:1.7.

This is still a lense that I overall highly recommend. It is inexpensive and you get great quality.

Exemple pics when stopping down to 1.7:

A play doll

A candle holder

I also used this lense with adapters on Sony NEX and micro 4/3 cameras with great results.
Forum Member

Registered: April, 2010
Location: Adelaide
Posts: 84

1 user found this helpful
Review Date: June 22, 2021 Recommended | Price: $50.00 | Rating: 8 

Pros: Sharpness. Light weight.
Cons: None really
Sharpness: 9    Aberrations: 8    Bokeh: 8    Handling: 8    Value: 8    Camera Used: P-50, Super-A, K-1   

I picked this up on a P-50 a few years ago. I didn't like the P-50 much and bought a lovely Super-A (Super Program) as a replacement. The lens works well on the Super-A and on my recently acquired K-1, it's simply stunning if you don't mind manual focus.

The Super-A came with a 50mm F2.0 M lens which I sold with the P-50. I don't mind the plastic used too much on the F1.7 KA.
I added a new (old stock) B+W 49mm UV filter of similar vintage to the lens.
Forum Member

Registered: October, 2018
Posts: 60
Review Date: February 15, 2021 Recommended | Price: $50.00 | Rating: 9 

Pros: Sharp, compact, auto aperture
Cons: None
Sharpness: 9    Aberrations: 9    Bokeh: 9    Handling: 8    Value: 9    Camera Used: k70 KP   

This lens produces sharp and beautifully ‘contrasty’ images, full of saturated colours and excellent resolution on the sensors of my KP and K70. In AE mode with focus confirmation, it is a joy to use. I wouldn't consider using the aperture ring, just put it A mode and forget it. The manual focus is not quite as smooth as other M and K lenses I own, hence the 8 for handling.

Registered: July, 2013
Location: People's Republic of America
Posts: 9,675
Review Date: January 8, 2020 Recommended | Rating: 8 

Pros: Sharp, cheap, easy to find, great colors
Cons: Plastic aperture ring, seems to lack the M 50 1.7 "magic" wide open
Sharpness: 9    Aberrations: 9    Bokeh: 9    Handling: 8    Camera Used: K20D   

This lens would easily be a 9 if it had a better aperture ring. I had two Auto Sears (made by Ricoh) lenses with plastic aperture rings and they both felt really great in use. But the one on the A 50 1.7 just gets lose with time and eventually breaks.

The other minus is that the M 50 1.7 has a certain "magic" to it wide open, that might be down to the M era coatings (my other M lenses have the same - even the much-unloved M 200 f4). It's hard to explain - the colors are not super-saturated but they are just so beautiful. The M 50 1.7 wasn't "dreamy" in any way - quite sharp in fact wide open!

And it wasn't just my M 50 1.7 being a better than average copy... I had another M 50 1.7 at one point and it was exactly as good, there was simply no difference between the pictures from both of them wide open (or otherwise).

I eventually sold my copy, but kept the M, and bought an F version of the 50 1.7 design when a good deal came along.

But for those who don't have the M 50 1.7 for comparison, don't let my comparison with the M 50 1.7 fool you. Maybe the M 50 1.7 has an extra 1% over the copy that I had of the A 50 1.7 - maybe other copies are better.

For my copies of the A 50 1.7, the characteristics are as follows:

-Reasonably sharp at full aperture (better than 50 1.4 designs by Pentax)
-Extremely sharp from f2 and smaller (same for all Pentax 50 1.7 designs)
-Great Colors and rendering
-Very good bokeh (not as good as 1.4 designs but still better than most zooms)

-For the price, really, nothing. It's still sharp enough wide open, and fantastic closed down. For a lot of people, having the A contacts will be more meaningful than the slightly better performance wide open that I see with the M version. Just keep the aperture ring always in the A position and you'll be good
Forum Member

Registered: July, 2019
Location: Kamloops B.C
Posts: 83

3 users found this helpful
Review Date: December 31, 2019 Recommended | Rating: 8 

Pros: Image quality
Cons: Plastic aperture ring
Sharpness: 9    Aberrations: 8    Bokeh: 9    Handling: 8    Value: 10    Camera Used: MX, Super Program, K-7, K-01, K-5, KP   

There is good value to this lens. It's a shame about the shoddily built plastic aperture ring because the rest of the lens is built quite nice, but if you just keep it in the "A" setting this is a non-issue. It is small and light yet the inner barrel and lens mount are metal, and the focus ring, although made of plastic feels smooth and well damped. I have used my copy for years and aside from the aperture ring there is no wobble or looseness and feels tighter than my modern HD Limiteds - I'm especially looking at you 21 and 70.

Image quality is typical of Pentax 50's which means to say its great. To my eyes the images it produces are indistinguishable from any of the f1.7's, as it should since they all share the same basic optical design and 6 blade diaphragm. No surprises here.

I really like this lens for international travel because it's so small and light, takes high quality images, yet it's easily replaced if lost, stolen or damaged. I don't like to take expensive camera gear traveling because it gives me "camera gear anxiety". This little lens is a part of cheap but potent kit I put together that allows me enjoy my travels without worrying about my gear, but still come home with excellent results.

For those who wish to mainly use this lens on an older film body that does not support the "A" setting I'd suggest skipping this lens and going for an M or K option as they are better built, but for a digital user this lens is golden.

I can highly recommend this lens to anyone who is on a tight budget but are in search of a high quality lens.

8/10 - good optics, poor aperture ring, great value.
Senior Member

Registered: May, 2019
Location: Agadir city -Morocco
Posts: 211
Review Date: December 27, 2019 Recommended | Price: $20.00 | Rating: 8 

Pros: it's a glorious lens I still use it, it makes an impressive sharpness and bokeh
Cons: absence (of course) of autofocus
Sharpness: 8    Aberrations: 3    Bokeh: 9    Handling: 3    Value: 8    Camera Used: K20D   

a glorious lens, its quality is optimal, and especially with a body full frame it gives an ideal bokeh.
Forum Member

Registered: September, 2017
Posts: 72

1 user found this helpful
Review Date: November 20, 2019 Recommended | Price: $25.00 | Rating: 9 

Pros: Excellent value
Cons: yes the plastic
Sharpness: 9    Aberrations: 8    Bokeh: 9    Handling: 9    Value: 10    Camera Used: istDs, ME, K-5   

Overall a 9.5 for this lens, yes the plastic is something that many people dislike, but considering its an A lens with this quality its a must have!
For portraits and stills where you can take your time, I prefer this lens over any other autofocus on, as it keeps you being focused and taking the right shot.
Senior Member

Registered: June, 2013
Location: Utrecht
Posts: 205

1 user found this helpful
Review Date: August 14, 2019 Recommended | Price: $20.00 | Rating: 9 

Pros: Optical quality, easiness as A-lens
Cons: Build quality, manual aperture setting is horible
Sharpness: 9    Aberrations: 10    Bokeh: 10    Handling: 6    Value: 8    Camera Used: Super Program A to K1ii   

This lens performs identical with it's M-sibling. Optical it is very good. It came 15 years ago or so with a Super Program-A for 35 Euros. Compared with the M-lens this is a "plastic not so fantastic". Only usable in A-setting, manual aperture setting is really horrible because of worn out plastic mechanics. I think I better remove inner spring-ball so for this one I can use my aperture ring silently without clicks for video shootings . Using this lens in A-mode anyway works fine.

See also

Site Supporter

Registered: October, 2017
Location: Sale, Cheshire
Posts: 225

1 user found this helpful
Review Date: May 30, 2019 Recommended | Rating: 10 

Pros: Sharp, good contrast low CA
Cons: manual focus technique needs practice
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 8    Value: 10    Camera Used: K-3   

A cracking little lens. I obtained this lens free from a camera club colleague and have been testing out its capabilities.
At f 1.7 the image is a little soft. At f 2 the image is sharp and at f 2.8 and beyond, very sharp. The contrast and colour rendition is very comparable to modern lenses.
I found the best technique for focusing (on the K-3) is to focus to the indicator light in the viewfinder - this gave consistently accurate focusing.
Some minimal CA occurred under the following conditions:
  • Out of focus areas in high contrast.
  • Intense sun reflecting on chrome.
Of course, this can be readily removed with editing software.
Generally, CA is very well controlled, in bright conditions.
Some flare (but not excessive) was evident when shooting into the sun, however using a lens hood may mitigate this.
Optically, a very impressive lens from the film era which is still excellent in the digital era.
Senior Member

Registered: February, 2017
Posts: 146

1 user found this helpful
Review Date: September 4, 2018 Recommended | Price: $35.00 | Rating: N/A 

Pros: Super cheap, super sharp images from f2.2, nice looking bokeh, small and light, ok CA resistance, smooth focus ring, full frame coverage
Cons: Not as sharp wide open? Can focus far but not to infinity.
Sharpness: 8    Aberrations: 8    Bokeh: 8    Handling: 10    Value: 10    Camera Used: Pentax K-70   

This is a surprisingly good old lens that is very affordable and produces very good images, absolutely comparable to some modern lenses.
Very sharp from f/2.2

I'm selling my modern Samyang 50mm f1.4 because it is much bigger and heavier and in most situations does not perform better.
Forum Member

Registered: August, 2018
Posts: 72
Review Date: August 28, 2018 Recommended | Rating: 9 

Pros: Cheap and realy good.
Cons: Manual focus. Boked, no made for.
Sharpness: 10    Aberrations: 9    Bokeh: 6    Handling: 8    Value: 9    Camera Used: K-x   

Very cheap, really good, but I prefer my FA50mm F/1.4
New Member

Registered: August, 2018
Posts: 5
Review Date: August 27, 2018 Not Recommended | Price: $37.00 | Rating: 4 

Pros: Small, built like a tank
Cons: My copy had terribly low contrast/flare. Fog inside?
Sharpness: 6    Aberrations: 5    Bokeh: 5    Handling: 10    Value: 10    Camera Used: K3 and ME Super   

Maybe my lens had some internal issue. Terrible contrast and flare. Unusable.
Add Review of SMC Pentax-A 50mm F1.7

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