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SMC Pentax-M 50mm F1.7

Reviews Views Date of last review
231 745,844 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 (Ascending) Showing Reviews 1-15 of 231
Inactive Account

Registered: September, 2006
Location: Lancaster, PA.
Posts: 2,041

1 user found this helpful
Lens Review Date: January 7, 2007 I can recommend this lens: Yes | Price: $28.00 | Rating: 10 

Pros: A Pentax Prime Lens with multiple uses
Cons: There are no negative aspects I can find

As one of Pentax's prime lens family this lens is very versatile. It can be used for many different applications. Used indoors as a portrait lens it renders crisp clear shots with a great DOF. It is a magnificent out door lens and again very crisp and clear for a walk about lens. Added to 2x or 3x Adapter it also makes a fine Macro lens.
Veteran Member

Registered: January, 2007
Location: St-Albert, Alberta, Canada
Posts: 333

1 user found this helpful
Lens Review Date: January 8, 2007 I can recommend this lens: Yes | Price: N/A | Rating: 9 

Pros: Very good and clear optics
Cons: none

This lens has been part of my kit for 14 years. Used indoor and outdoor. Sharp images and contrast with great DOF. Used it for night exposures which has shown great color correction even after 5 minutes exposures at f1.7.
Veteran Member

Registered: September, 2006
Location: North Idaho
Posts: 665

1 user found this helpful
Lens Review Date: January 8, 2007 I can recommend this lens: Yes | Price: N/A | Rating: 8 

Pros: outstanding optical quality, outstanding build quality
Cons: none

In the late 70's, this was the lens that came with your film SLR body when you couldn't afford the f/1:1.4 version of the 50mm. This was the case with me. I was a newlywed and didn't have much expendable income. This lens is so good, that I still have it to this day, and even use it on occasion even though I have 'better and faster' 50mm lenses, (FA50/1.4 and A50/1.2).

Like all M series lenses, it is of all-metal construction and has a firm, positive focus ring on it. It is fairly compact, and without checking the specs, I'd venture to say that it is the smallest, in physical size, of any Pentax 50mm produced. Even slightly smaller than the 2.0 lens.

If you have need of a manual focus 50mm lens, you can certainly do worse with other lenses, and rarely better.

Highly Recommended. Given an 8 rating only because I reserve 9 and 10 ratings for Limited, "*", and other outstanding Pentax lenses.
Inactive Account

Registered: September, 2006
Location: Folsom, CA
Posts: 322

1 user found this helpful
Lens Review Date: January 10, 2007 I can recommend this lens: Yes | Price: $20.00 | Rating: 9 

Pros: Nice focusing ring, great colors
Cons: None so far

I love this lens. This was the first upgrade I bought after the kit lens. Takes great pictures, very sharp, great color. I had a hard time with manual focus, just because its harder with dSLRs to see in the viewfinder. I have since purchased an F50/1.7, so this has been relegated to being attached to my Extension tubes for Macro work, where the focusing ring is a pleasure to use over any of the Autofocus lenses. This lens is probably the best deal on the market right now - not as desired as the 1.4 lenses, but to my eye just as good!
New Member

Registered: December, 2006
Location: Holland
Posts: 1
Lens Review Date: January 24, 2007 I can recommend this lens: Yes | Price: N/A | Rating: 8 

Pros: I had buy this lens a 14 days ago and I try to use the lens in M mode at my K100D, so to see he gives sharp,nice colors photos
Cons: it cost more time to make a photo, then in auto

When you learn how to use this lens in the M mode, I think its costs more time to take a photo, then you can make a photo at auto, but you can changing in F; settings. And at last you can get a better photo. (Non working link removed)

1 user found this helpful
Lens Review Date: January 27, 2007 I can recommend this lens: Yes | Price: $55.00 | Rating: 10 

Pros: very fast lens, incredible sharp, light , elegant...
Cons: After use this lens, look to the Kit lens make me feel sick...

This is a great, cheap lens. If you can dont let it go. Take one for you.
Veteran Member

Registered: December, 2006
Location: SC, USA
Posts: 383

1 user found this helpful
Lens Review Date: February 24, 2007 I can recommend this lens: Yes | Price: $10.00 | Rating: 8 

Pros: Fast, Small, Light

Very good lens when you need something to perform in low-light. I personally prefer an autofocus lens when there is adequate lighting, but if lighting is low this beauty is the first to come out of the bag.
Veteran Member

Registered: December, 2006
Location: Mississauga, Ontario, Canada
Posts: 2,530

1 user found this helpful
Lens Review Date: March 5, 2007 I can recommend this lens: Yes | Price: $55.00 | Rating: 9 


This lens is definitely my favourite. The lens is extremely versatile in almost all situations. Because of the 1.5x crop factor, you will need to switch lens when stepping into smaller rooms. Looking at the bokeh from this lens, as well as the 1.4 is addictively pleasing.

Highly recommended!
Forum Member

Registered: September, 2006
Location: Queen creek, az
Posts: 81

1 user found this helpful
Lens Review Date: March 25, 2007 I can recommend this lens: Yes | Price: $25.00 | Rating: 9 

Pros: sharp, amazing contrast
Cons: none (on a *ist ds at least)

My favorite lens for pure iq
New Member

Registered: June, 2007
Location: Halifax, Canada
Posts: 22

1 user found this helpful
Lens Review Date: June 21, 2007 I can recommend this lens: Yes | Price: $40.00 | Rating: 10 

Pros: Inexpensive. Fast. Versitile.
Cons: None.

Again, i'll state that M-series lenses are the love of my life. this is the lens that made me think that.

It's small for its features. It's faster than most companies 50mm's. Tack Sharp! Possibly the sharpest lens i own. As nice to use on film as it is on digital, in fact this lens is on my k10d more than any other. I wish it was more fucntional with the K10's features, but it's great for wide-open shooting in all conditions. I did have to bracket my exposures on the k10 sometimes though. I love the B&W film shots i've got from it, especially when paired with a yellow filter to up it's tasty contrast just a bit more. Color rendition is perfect on film and digital.

My favorite lens. I love it so much that i bought a second one.
Senior Member

Registered: August, 2007
Location: Los Angeles
Posts: 233

2 users found this helpful
Lens Review Date: January 20, 2008 I can recommend this lens: Yes | Price: $40.00 | Rating: 10 

Pros: Super Sharp, Even wide open! Great value for the money.
Cons: None

I have a whole collection of 50mm's:

M1.4, M1.7, M2.0 and the FA1.4.

The are fun to play with in the evenings when the light isn't so great. Recently I've taken to testing them on a tripod against different targets.

The M1.4 and FA1.4 perform almost identically. I checked the lens element diagram and the element/groupings are almost the same so no surprise there.

The real surprise was when the M1.7 was significantly sharper wide open from f1.7 to f2.0. It took till f2.8 for the f1.4's to catch up.

This is an incredible lens. I only wish they still made an autofocus version.

If you had to choose a manual focus 50mm. This is the one. I have the M1.4 as well and this one is better.
Senior Member

Registered: July, 2007
Location: York Region, ON
Posts: 277

1 user found this helpful
Lens Review Date: February 1, 2008 I can recommend this lens: Yes | Price: $40.00 | Rating: 9 

Pros: Size, Weight, IQ, Speed, Build Quality
Cons: Size, Stop Down Metering

Just got this lens the other day and I am very impressed. If you plan on picking up any of the 50mm primes I would highly recommend this one or the faster version of it. Its a solid lens, no wobbly parts and well put together. The size is great as it makes the DL (or K100D) nice and light and not as big but also the focus ring is small. But to conter that the focus ring is very nice with a nice long throw for precise focus.
IQ is great as well. Did a few informal test with the KitLens and equal settings and it was clearly sharper and contrast was nicer, a very nice upgrade!
All in all a very nice compact lens that can be had for a great price these days!

(Non working links removed)

Senior Member

Registered: February, 2008
Location: Paris
Posts: 222

1 user found this helpful
Lens Review Date: April 5, 2008 I can recommend this lens: Yes | Price: $50.00 | Rating: 8 

Pros: Small, very well built, sharp.
Cons: Metering on GX-10, No AF

This is the first lens I have ever bought that is not a Kit lens. It is very sharp from f1.7. The bokeh is very nice most of the time, but under some conditions can be quite harsh.
It is extremely well built and the focus is smooth. I can't actually find anything wrong with this lens and if i give it a 9 it is because of the body.
The fact that it does not AF can be a problem but the metering is what is the most annoying. I have been having a hard time finding the trend on how my GX-10 meters. It seams to be a little different than on the K10D.
Here is a sample picture at f5.6:

edit: Now that I have played with some other lenses, I would have to give this one an 8 only.
If the optics were the same and it had AF i would give it a 9, if the bokeh was better it would get a 10.

1 user found this helpful
Lens Review Date: April 28, 2008 I can recommend this lens: Yes | Price: $50.00 | Rating: 9 

Pros: build quality, dirt cheap, sharp and wonderful *drawing*
Cons: prone to flare, six aperture blades, more complicated metering, manual focusing

This is my first acquisition of manual focus glass and I have to say I'm very glad I went for something a bit less conventional. One often hears in lens reviews about a lens' *drawing* characteristics, but in this age of computer-designed slow zoom lenses, I never felt I was able to appreciate what reviewers were talking about, and figured they were just imparting their own romanticized ideals onto the lens. With the M 50/1.7, I definitely have an improved regard for this idea, for it really feels like it has its own distinct personality in the way it takes pictures. Much of this is likely due to the beautiful bokeh that exists at wide open apertures which is smooth and soft.

My only criticisms are the occasional green/magenta logitudinal CA that exists on some out of focus boundaries, and very occasional (only one pic so far) example of hexagonal rather than circular bokeh, which can't really be called a negative.

In terms of using it on a dSLR (the K100D), it has gone remarkably smoothly considering this is a 30 yr old lens, though it has been a learning experience all the same. Considering the impossibility of doing the same on Canon or most Nikon bodies, this is an impressive feat. There are two ways to meter, either with aperture-priority wide-open only, or in full manual mode using the AE-L button (refer to this dpreview forum thread for a comprehensive guide to using manual-focus glass on Pentax's dSLR's: ) I've noticed a tendency for the camera to underexpose by about 0.7 stop in most light, so compensate accordingly (the K100D's metering itself is not always the most reliable.)

My biggest challenge so far has been focusing, as I'm not used to manual focusing. This is not made easier by the lack of a split prism, the very thin plane of focus at wide open apertures, and the K100D's dark viewfinder, though the viewfinder certainly looks brighter with the 50 mounted rather than the kit lens. I have pretty good eyesight so I imagine this would be even more challenging for someone with poor eyesight/eyeglasses. With practice I hope this will become less an issue.

One last note, the build quality really is something to be appreciated in person, as it is made just like a rock (and weighs nearly as much as the 18-55 which is 2-3x as long.) It puts many modern $1000 AF lenses to shame from any manufacturer, one area where they truly don't "make em like they used to."

All in all, this is a very cheap way to investigate the possibilities of both low-light and shallow DOF photography. I don't think any Pentax user who has not experimented in this area would be disappointed with the results and the amazing value proposition of this lens (consider a new AF lens from the major marques are b/w $200-300, and significantly less well-built.)

EDIT: since my initial review, have had significantly more usage with this lens, and have come to really notice its truly horrible tendency to flare, as well as bad purple fringing on light sources, even like street lights. Well apparently this is a common affliction with wide-aperture lenses, but nonetheless a bit annoying. I wouldn't mind if it was just an issue with the sun since I mostly use this indoors/at night but its an issue even with common lighting sources. Oh well, it's not an issue that would be prevent me from recommending this lens, just something to be aware of.
Veteran Member

Registered: April, 2008
Location: Jakarta
Posts: 1,067

1 user found this helpful
Lens Review Date: April 29, 2008 I can recommend this lens: Yes | Price: $40.00 | Rating: 8 

Pros: great bokeh, crisp, fast
Cons: very little PF found

i just got this lens for maybe one month. having testing it days and night after that.

one of the sample images i took with this baby, herewith i post it here.

i really cant imagine how come a small thing like this can create a beautiful picture like that
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