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SMC Pentax-M 50mm F1.7

Reviews Views Date of last review
231 745,834 Mon December 23, 2019
Recommended By Average Price Average User Rating
100% of reviewers $40.73 9.37
SMC Pentax-M 50mm F1.7

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

The SMC Pentax-M 50mm F1.7 is a common standard lens that shipped with many early Pentax bodies.

SMC Pentax-M 50mm F1.7
©, sharable with attribution
Image Format
Full-frame / 35mm film
Lens Mount
Pentax K
Aperture Ring
Yes (no 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
Dedicated hard case
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Diam x Length
63 x 31 mm
185 g
Production Years
1977 to 1984
Engraved Name
smc PENTAX-M 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 RingFull-Frame SupportDiscontinued
Price History:

Add Review of SMC Pentax-M 50mm F1.7
Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 151-165 of 231
Senior Member

Registered: February, 2010
Location: Bærum, Norway
Posts: 101

1 user found this helpful
Lens Review Date: April 15, 2011 I can recommend this lens: Yes | Price: N/A | Rating: 8 

Pros: Fast, sharp, build quality
Cons: Functionallity on DSLR

Great lens, but MF and manual exposure is not really for me if I don't have to...
Forum Member

Registered: February, 2011
Location: Athens, GA
Posts: 68

1 user found this helpful
Lens Review Date: April 11, 2011 I can recommend this lens: Yes | Price: $43.00 | Rating: 8 

Pros: low light performance, very pleasing bokeh, very nice FL for potraits and candids
Cons: Chromatic aberration, kind of soft wide open

This is the first lens I bought after getting my k-x and it was a worthwhile investment. In low light it is my default go to lens and produces some amazing shots. It's also quite good for close-up/subject isolation for artistic shots.

At first I would have said this lens is very sharp, however upon getting better glass (SMC-K 35mm) I'm afraid it falls very short in terms of sharpness when wide open. Additionally, it also produces a fair amount of chromatic aberration under certain conditions. This may be particular to my lens. For these reasons I cannot give this a 9.

Overall this is a very solid lens, especially for the price. I'd highly recommend it for beginners who want to get better at photography. It (almost) forces you to get familiar with M mode and after a bit of use you really begin to get a feel for the holy triad. Pick this one up if you get the chance!

Registered: January, 2011
Location: Skåne, Sweden
Posts: 462

1 user found this helpful
Lens Review Date: April 7, 2011 I can recommend this lens: Yes | Price: $50.00 | Rating: 10 

Pros: Build quality, focus, very sharp, compact
Cons: None at this price
Sharpness: 10    Aberrations: 8    Bokeh: 9    Handling: 10    Value: 10    Camera Used: K-x, K-5, ME Super   

  • Build quality
  • Compact size
  • Sharpness
  • Amazing value
  • Handling

  • Purple fringing under some conditions

This has to be one of the most common old Pentax-lenses, and therefore fetches very low prices. I paid $50 for a mint copy with original box. For that kind of money, it has the highest price/performance ration of all my lenses! It is sharp already wide open, with a pleasing bokeh. That it is sharp wide open is good for use in Av mode on modern DSLRs, M-mode and green button is great, but makes for slower handling. Stopping down just one or two steps boost sharpness and contrast even more. It is very compact and well built, makes a perfect fit on the ME Super but also on the small K-x (and with matching chrome details!). Manual focus is very smooth and precise, simply a joy to use.

I would very much recommend this lens to any user, beginners for great value and to exploring manual glass and all others simply for its performance. First picture is with "trap focus" on the K-x, second is on the ME Super.

My pictures on flickr with this lens
New Member

Registered: March, 2011
Posts: 1
Lens Review Date: March 28, 2011 I can recommend this lens: Yes | Price: $68.00 | Rating: 9 


After reading all the reviews I decided to pick one of these little betties up. Now, I might be a greenhorn photographer but when the first 50 snaps come out like mine did you can't complain. This is my first lens other than the kit lenses that came w/ my k-x and I'm not sure I'll ever use the kit lenses again.
New Member

Registered: November, 2010
Location: Yokohama
Posts: 1

1 user found this helpful
Lens Review Date: March 28, 2011 I can recommend this lens: Yes | Price: N/A | Rating: 10 

Pros: All
Cons: none

This is the lens I began photography on and it will always be a favorite. When I go hiking, camping, or trekking up a mountain, I always bring this one since it's light and tough.
New Member

Registered: January, 2011
Posts: 1

1 user found this helpful
Lens Review Date: March 17, 2011 I can recommend this lens: Yes | Price: $80.00 | Rating: 10 

Pros: quality, sharpness, contrast, colors, build and everything
Cons: in fact... none

I it was all said already. This lens is basically a reference for build and image quality.

It can take any photo at any circumstances.

The only downside of this lens is that when someone ever uses it, they wish that every lens they own will be up to overall quality of M50/1.7...

I am using it with K20D, low-light sample from yesterday:
Senior Member

Registered: January, 2011
Posts: 258

5 users found this helpful
Lens Review Date: March 2, 2011 I can recommend this lens: Yes | Price: $66.00 | Rating: 9 

Pros: sharp as macro lens, metal and glass, small, IQ, ...
Cons: not an A(minor problem if you use DLSR), but solvable by a little mode

Great lens! I have bought the camera with it. The IQ is amazing, no CAs at all, perfect micro contrast, more resolution then you will ever need. If you can find two buy tree .

this is from today, I have compared it with my FA 50 1.4

PS I have missed the focus a little on the M lens prom 2.0 to 4.0 it is obvious but it is enough to get an impression of the optic differences between the expensive FA and cheep M.

PS2 I'm giving 9/10 because of the functionality with DSLR. Otherwise if this was an A or AF lens it was going to be the best 50mm from Pentax in this size. Maybe only the 50 1.2 is better optically.
New Member

Registered: March, 2010
Location: North of switzerland
Posts: 1

1 user found this helpful
Lens Review Date: February 28, 2011 I can recommend this lens: Yes | Price: $45.00 | Rating: 9 

Pros: IQ, sharp, built like a Limited, (smooth) Focus ring, f1.4, price, great colors
Cons: no AF :(

This lens is superb. With AF it would get a 10.

1 user found this helpful
Lens Review Date: February 16, 2011 I can recommend this lens: Yes | Price: $35.00 | Rating: 10 

Pros: Very small, good optics, smooth focusing, usual M build quality, sharp
Cons: none

Excellent piece of glass, nothing to say negative actually.
Forum Member

Registered: January, 2011
Location: Leipzig
Posts: 64

3 users found this helpful
Lens Review Date: February 11, 2011 I can recommend this lens: Yes | Price: $45.00 | Rating: 8 

Pros: sharp, well built, cheap
Cons: bokeh can be quite unpleasent at f2 and f2.8

In principle I do like this lens, it is pretty sharp (maybe even a bit sharper than the Smc-M f1.4 at f1.7-f2), and its built quality just feels good.

On the minus side stand the bokeh!
In my opinion it is not only the rather genreal 6-blade vs. 8-blade "disadvantage", but more the strange aperature shape at f/2.0 to f/2.8 (see sample pictures!).
In most situations, however, this effect doesn't appear that strong, which is why I still decided to give this lens an "8".

bokeh comparison at different aperatures:
Junior Member

Registered: June, 2010
Location: Nanaimo b.c.
Posts: 34

1 user found this helpful
Lens Review Date: January 2, 2011 I can recommend this lens: Yes | Price: $10.00 | Rating: 8 

Pros: Cheap lens, great build quality
Cons: Have a hard time focusing on my k7/ k200

All the reviews I read point to the fact that this is a great lens. I do LOVE the colours, richness, bokeh, but find it fairly hard to focus with my k7 and k200.
(then again, could be my eyes!)
Dont have that problem with my tak 55 f17 though.
Thinking of getting an fa 50 1.4.
Veteran Member

Registered: April, 2010
Posts: 759

1 user found this helpful
Lens Review Date: December 19, 2010 I can recommend this lens: Yes | Price: N/A | Rating: 10 

Pros: Sharpness, Size, Color and Contrast, Price

Simply a great standard prime lens—small, light, fast, and sharp. I have all the fast 50mm (f1.2,1.4,1.7,2) that Pentax has made, but this is the one I take with me on trips. It’s light and small and not too valuable so I don’t have to worry about. Build quality is excellent--not quite as good at the Takumars (or even my K50 1.2 or M50 1.4) but no one will be disappointed, it is metal and solid. Focusing is well damped and smooth.

It also takes fantastic pictures. Rendering is very realistic and neutral. Colors and contrast are excellent. Sharpness is really a strength of this lens—it’s surprisingly sharp wide open and razor sharp once stopped down (by f2.8, I cannot tell anymore what aperture I set). I’m not sure if it’s sharper than my f1.4’s or f1.2’s, but it certainly isn’t any softer! I have printed a shot from this at f8 at 27” x 18” and it holds up incredibly. It also has a flatter field of focus than the other fast 50’s, which makes it better suited for copy work. I used this for some time with the Vivitar 2x Macro Tele-converter and had excellent results. Bokeh is a little more hit and miss—with only 6 blades, you can get hexagonal spectacular highlights when stopped down. Wide open, the bokeh is, in my opinion, not as good at the f1.2 or f1.4 optics Pentax has offered. It is also libel to some bokeh fringing (LoCA) wide open. Otherwise, aberrations are well controlled and are better than the other Pentax 50mm optics. However, I have found the sweet spot of this lens at f2.8-4 and a distance of about 2-4 feet)—at this not only is it incredibly sharp, but the bokeh is very smooth and creamy in the background, giving great pop and perhaps that elusive 3d effect.

Considering the price of this lens, and it’s fantastic performance, I will never end up selling it. Hence, I have given it a 10. If I had to keep one fast 50, I would have a hard choice between this and the S-M-C Takumar 50mm f1.4.
Junior Member

Registered: November, 2009
Location: Bloomington, IN
Posts: 37

2 users found this helpful
Lens Review Date: December 11, 2010 I can recommend this lens: Yes | Price: $60.00 | Rating: 10 

Pros: Build Quality, Very Sharp IQ, Pleasant Bokeh
Cons: None

This was my first lens purchase after the kit lens (18-55). I wanted a fast fifty but couldn't justify spending hundreds of dollars on a new auto focus lens. After doing extensive research on various M and A Pentax lenses (thanks to this forum!), I purchased my copy of the M 50mm f/1.7 from the Marketplace. I paid $60 USD for my lens, which was in near-new condition. After six months of use, I’ve fallen in love with this fantastic piece of Pentax glass. Since June, I can count on one hand the number of times it’s been off my K20D.

Image quality is excellent and the lens is built like a tank. Honestly, the build quality is second to none! It's very compact and a perfect travel companion in my kit bag. I've been very pleased with the sharpness, even when wide open. At f/1.7 the depth of field is razor thin and the bokeh is soft and dreamy. My only issue thus far (and it’s really just “newbie error”) is that when shooting wide open, you need to be very careful not to accidentally bump the focus ring. Even the slightest nudge can throw your intended focus point out of focus, giving the impression of a soft image. That being said, when stopped down to f/2.8 or more, image sharpness is unreal.

I've used this lens both outdoors and indoors with superb results. I shot an indoor concert recently with difficult lighting and this little lens performed flawlessly.

All in all it's been the perfect lens for me to improve my MF skills. I'll certainly buy modern glass in the future but I'll always keep a spot in my bag for vintage Pentax glass like the M 50mm f/1.7. I recommend it to anyone looking for a reasonably priced low-light lens. A solid “10.”

Taken at f/2.8 ISO 400 K20D

Taken at f/1.7 ISO 200 K20D

Registered: April, 2009
Location: Madrid, Spain
Posts: 6,207

1 user found this helpful
Lens Review Date: December 6, 2010 I can recommend this lens: Yes | Price: $55.00 | Rating: 9 

Pros: Very small, good optics, smooth focusing, usual M build quality, a bit magic
Cons: Slightly soft before f2.8 (but very useable wide open)
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 10   

Please note that this review is based on use on the K200D with a Katzeye split-prism focusing screen installed. With the standard screen this lens will be considerably harder to focus properly when close to maximum aperture.

When I first got it as my first piece of old Pentax glass, I had virtually no shots in focus (partly because I thought it was stopped down when it wasn´t, partly lack of MF practice and mainly because I didn´t have a split-prism focusing screen installed yet). Things have improved since then.

I´ve just written a review of the K55/1.8 lens in which it is largely compared to this one, and the M50 comes off worse. Now that I think about it that seems a little unfair and is mainly based on the K lens being the sharper of the two wide open, but that´s not to say that the M50´s merits are few. In fact, in general optical characteristics there´s very, very little between the two. I prefer the larger size of the K, but the smaller & lighter M is usually chosen for travelling. Indeed, the tiny nature of this lens makes it very convenient for tucking into small spaces in a camera bag where nothing else would fit. The K is slightly longer which makes it better for face-only portraits. But with the crop factor of APS-C, the 50mm is more versatile as a general low-light lens. So really it´s only the sharpness of the K that makes it “better”, everything else is a question of using the right lens for the right job. Despite the similarity in focal length & speed I won´t be selling either.

The M50 is sharp enough wide open to be useable in low light, though for portraiture in good light the slight softness is more apparent. Like the K55, by F2.8 the lens is nice & sharp, and so that´s where I use it most often unless I need the extra speed. The colour & contrast are very good, though not up to the superb standard of the M85/2. Bokeh is always smooth (see examples below) and colour fringing virtually non-existent. The only optical problem I´ve seen from it was nasty (really nasty) green colour distortion once while trying to get a picture of a streetlight in the snow. I understand this might be due to the coatings of the lens.

These lenses are not hard to find (unlike the K55) and are pretty cheap, and the performance to price ratio is nothing short of outstanding.

Here are a few examples from last summer´s trip to Austria. Note that I´ve processed these for a “filmy” look, hence the colours. Note also that the majority of them were wide open or at F2.

Edit 11/12/2011.

A year on, I have upped my score for this lens from an 8 to a 9. It really is superb and I love it more and more. The M50 f/1.4 I got just after I originally reviewed this lens gets less use, even though it performs similarly. The IQ, colours, general look & the feel of using this lens all combine to add a magic to it. The A version performs just as well as the M, but lacks the magic due to the poorer build quality & the use of the control wheel (rather than the aperture ring) to change the aperture setting.

Every Pentax user must own this lens, even if they already have other fast fifties.
Inactive Account

Registered: October, 2010
Location: Fairfax, VA
Posts: 29

1 user found this helpful
Lens Review Date: December 5, 2010 I can recommend this lens: Yes | Price: $33.00 | Rating: 9 

Pros: Smooth focusing ring, lightweighted, nice colors, crisp image
Cons: hard to focus (need some practice)

I started to look for 50mm lens for reverse macro purpose, and ended up with two little lenses. First one is f2 (made in Taiwan or Korea, not sure), which gives me average IQ, and the second one is this lens (made in Japan). To me f1.7 seems much better than f2, especially when I use it for reverse macro shooting which requires a lot of light. I would imagine f1.4 lens might be even better (but it’s much more expensive)?
I won both lens over eBay auctions and so glad I did! These are my first manual prime lenses. Besides occasional use for reverse macro shooting, I keep the f1.7 lens on my K-x most of the time for normal use since I bought it. The build quality is really solid, and it’s a perfect match to my K-x. It renders beautiful colors, crisp images, suitable pretty much for any situation, especially for low light. For indoors, I had to use high ISO (1600 – 3200) with the kit lens (i.e. 18-55mm DAL), but now I can use 800 or even lower ISO with this lens. No flash of course.
I’ve been using digital camera since ten years ago when I bought my Nikon CP995, and using AF all the time since then. There is an obvious advantage for AF, for example, when I do bird shooting with my 55-300mm DAL, I have to use AF for fast action. Now back to manual focus, it's kind of hard for me to get right focus, but I think it’s fun, and once it’s got focus, the image is very sharp! I guess that’s the advantage of prime lens? I still need more practice to get used to it. I like the feeling to move the focusing ring. Over all, it's an amazing little lens. I love it! I would say it’s a must for any DSLR owner (of course, the cheap way). If you can afford it, FA version is there, but optically they are pretty much the same as I read those reviews.
The photo below was shot with this little lens at sunset as testing low light condition as well as color rendering.
Add Review of SMC Pentax-M 50mm F1.7

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