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Wednesday, April 4, 2012

Pentax SMC M 50mm f1.7 - Legacy 50mm. Which one is the best? Part 2

This little Pentax M SMC 50mm f1.7 is a lens with a solid reputation. My impressions in most aspects reflects this reputation.

Lens is pretty small 3.1cm height, 185gr, 49 filter thread, makes it actually one of the smaller 50 mm lenses (not counting pancakes). Minimum focus distance is around 45cm where it achieves 0.15x magnification.

Lens is made of 6 elements in 5 groups. Aperture has 6 blades.

I did pay 60 USD for the lens which seems to be a bit over average value.

Body is metal, focus ring is rubberized and focus is very smooth.It takes around 200°for the full focus drive.
Front element extends during focusing toward closer distances, but it does not rotate.

Overall build quality is good, but not exclusive. Comparing it to todays plasticky nifty fifties, it feels like Rolls Royce however.

Lens and Camera:




Following test shows lens character, color, contrast and out of focus rendition at most apertures. Good to note is that aperture range is from f1.7 to f22 and the lens has 1/3 aperture stops in between. Not so often to be found at this price level.
NEX 7 + Asahi SMC Pentax M 50mm f1.7 at 1.7
NEX 7 + Asahi SMC Pentax M 50mm f1.7 at 2
NEX 7 + Asahi SMC Pentax M 50mm f1.7 at 2.8

NEX 7 + Asahi SMC Pentax M 50mm f1.7 at 4

NEX 7 + Asahi SMC Pentax M 50mm f1.7 at 5.6

NEX 7 + Asahi SMC Pentax M 50mm f1.7 at 8
NEX 7 + Asahi SMC Pentax M 50mm f1.7 at 11

NEX 7 + Asahi SMC Pentax M 50mm f1.7 at 16

NEX 7 + Asahi SMC Pentax M 50mm f1.7 at 22
Here are the 100% crops of the focus area. 
As you can see, lens is slightly softer wide open, which for a portrait lens might be good. From 2.8 up to 11 it is very sharp in the center, reaching its best between f5.6 and f8. Difraction hits from f11, but I can imagine it being used even at f22 with some additional sharpening.

Resolution chart is shown bellow with respectful 100 crops.
Distortion is very well controlled and should not be an issue at all.

Here are couple of portraits in a natural light without flash. This is probably the best use of this lens on APS-C.
Pentax SMC 50mm f1.7 at 1.7

Pentax SMC 50mm f1.7 at 2.8


Bokeh is very nice and smooth with this lens. Not the best one among 50ties but very competitive.
Pentax SMC 50mm f1.7 at 1.7

Pentax SMC 50mm f1.7 at 4
As the lens at f5.6 and f8 is nicely sharp across the frame, it can serve well as a short tele for the landscape. 49 mm filters (polarizer, ND, grade) are not that expensive, which is another plus.
Pentax SMC 50mm f1.7 at 8

Pentax SMC 50mm f1.7 at 8

Pentax SMC 50mm f1.7 at 8 HDR
Conclusion:
Pentax M SMC 50 f1.7 is a great value for the money. It is small, light, and there are lot of them around making the price reasonable. Slightly softer at f1.7 it reaches very good figures from 2.8.
CA might be an issue wide open, but I can't show you tests for it, as I am first trying to get the lens hood to test for it and flare resistance at once.
Bokeh is good but not perfect and you should either like or dislike 6 blades aperture. I prefer 7.

To your usual kit zoom, this lens can be a great addition for low light shots and subject isolation when needed. It will certainly exceed kit lens at 50mm also for the landscape.
You will end with a MF only and no info reported to camera, being able to shot in A,S or M mode, but you will also end with over 200 saved USD, and afford couple of other legacy primes.


5 comments:

  1. Thank you for your kind words.

    ReplyDelete
  2. Thank you for your exelent review

    ReplyDelete
  3. Hi, thanks for the great review. Do you know, whether there is thorium glass in this lens?

    ReplyDelete
    Replies
    1. Hi,
      there is no radioactive glass in this lens as far as I know. Unlike Takumars 50/1.4 (except the first version), this lens doesn't yellow by time.
      Regards,
      Viktor

      Delete
    2. Thank you for your answer. You really helped me out.

      Delete