3

What are difference between canon 50 mm f/1.8 STM vs canon 50 mm f/1.8 II ? which is better to buy?

SrujiTh KalluRu
  • 85
  • 2
  • 3
  • 8

2 Answers2

9

The STM version replaces the II version. Optically, they are identical. However, the STM has several advantages:

  • 7 rounded aperture blades vs. 5 non-rounded (no more pentagonal bokeh)
  • Metal lens mount vs. plastic
  • A much improved manual focus ring
  • STM vs. Micro Motor (should be faster and much quieter)
  • FTM (Full Time Manual) focusing
  • 13.8" (350mm) MFD (Minimum Focus Distance) vs. 17.7" (450mm)
  • 0.21x MM (Maximum Magnification) vs. 0.15x
  • 49mm vs. 52mm filter size (though not really an advantage from my perspective)
  • Narrower f/22 aperture available vs. f/16

All that for the same price! To answer your question: get the STM version.

crunch
  • 996
  • 6
  • 9
  • 1
    Note that while in this particular comparison the STM version is both quieter and slightly faster: In most cases when comparing comparable non-STM and STM lenses the non-STM lens will usually be faster to focus and the STM lens will be quieter. This is especially the case if the non-STM kens has an UltraSonic Motor (USM) (and most Canon lenses other than the cheapest consumer grade lenses use USMs). – Michael C Jul 03 '15 at 13:51
  • If you compare STM versions of lenses that existed previously as non-STM lenses, then the STM lenses are both faster and quieter: 18-55, 18-135, and 55-250. There are no Canon lenses with USM and STM versions so that's comparing apples to oranges. – crunch Jul 03 '15 at 15:01
  • EF 24mm f/2.8 IS USM vs. EF-S 24mm f/2.8? – Michael C Jul 03 '15 at 15:51
  • Not to mention "comparable" doesn't have to mean a direct replacement. The EF-S 17-55mm f/2.8 IS USM is a lens often compared to the various versions of the EF-S 18-55mm kit lenses. – Michael C Jul 03 '15 at 15:55
  • USM lenses in the same focal length and aperture range are uniformly faster focusing than STM lenses in the same focal length and aperture range. But they are not quieter. – Michael C Jul 03 '15 at 15:57
  • EF 24mm f/2.8 IS USM vs. EF-S 24mmf/2.8 STM? – Michael C Jul 03 '15 at 15:59
  • EF 24 and EF-S 24 aren't really the same - not even the same mount! The EF lens is much bigger and has to accommodate a significantly larger image circle. So not the same design at all. Also, as to whether or not USM is faster than STM across the board, that's debatable too. See https://www.youtube.com/watch?v=pmrvBcXYcwU. At some focal lengths the STM is clearly faster. The same channel has another video comparing the older 70-210 to more modern USM lenses without much difference. – crunch Jul 03 '15 at 19:18
  • ALL EF lenses and all EF-S lenses will mount on any camera that accepts any EF-S lenses. It is the same mount with an additional tab on the lens side to prevent placing an EF-S lens on a non APS-C camera. My original comment said nothing about same design! It said comparable. And they are. Both can be considered for use with any Canon EOS APS-C camera. Both provide the same field of view. Both have the same maximum aperture. That's what comparable means. – Michael C Jul 04 '15 at 00:49
  • And it's still comparing apples to oranges. Most non-USM lenses focus faster than the 85/1.2. And some STM lenses focus faster than some USM lenses across similar focal lengths. – crunch Jul 06 '15 at 09:07
  • Name one STM lens that focuses faster than an USM lens with similar focal length and similar maximum aperture. The EF 85mm f/1.2 L is notoriously slow because of the weight of the internal focus element. The EF 85mm f/1.2 L II, while still fairly slow, is not as slow as the original. Any f/1.2 lens in that focal length range is going to have a large diameter, heavy focus element to be moved. USM are faster. STM are smoother and quieter. – Michael C Jul 06 '15 at 22:41
  • Refer my linked youtube video in previous comment. However, that's not the same aperture. – crunch Jul 07 '15 at 13:11
1

Go to The-digital-Picture.com, search for Canon 50mm f1.8 STM review, click on "Image Quality". This web page will let you see the images of a resolution chart as taken with the selected lens. You can choose what camera body, the focal length (if it's a zoom lens), the f-stop, and a different image will be shown. You can choose another lens on the right side to compare. In this case you can choose the Canon 50mm f1.8 II. Move your mouse pointer on top of the little arrow at the top of the image and it will switch to the image taken by the second lens. Move the mouse away, it will show the first image. I find this lens comparison site very useful.

From the sites comparison between the 2 50mm lens, the STM lens produces slightly better results from f1.8 up to f8 (especially the mid-frame part of the images), when both lenses become equal. So I think they may not be optically the same.

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=989&Camera=453&Sample=0&FLI=0&API=0&LensComp=105&CameraComp=453&SampleComp=0&FLIComp=0&APIComp=0

Tat Lau
  • 26
  • 1
  • Canon's Chuck Westfall has already commented that the optics are the same. The difference that Bryan at TDP is showing is almost certainly sample variation - the build quality on the previous generation wasn't very good. – crunch Jul 10 '15 at 06:47