Are 50 1.8s better than 1.4s?

ThatCanonGuyThatCanonGuy Registered Users Posts: 1,778 Major grins
edited January 17, 2011 in Cameras
http://www.adorama.com/alc/article/50mm-lens-shoot-out-f18-or-f14

Interesting. Of course, they don't mention that the 1.4s have better AF and build. I think some of the comments do. For me, it doesn't change anything: if I ever want a 50mm, I'll buy a 1.4. More because of the AF than anything else.

Comments

  • MomaZunkMomaZunk Registered Users Posts: 421 Major grins
    edited January 15, 2011
    I have the Nikon f1.4G. It is extremely slow AF. My 18-200mm 3.4-5.6 is faster at focusing.
    I like the quality and low light performance, got to use it at the Children's museum today with the kids. Just have to exercise a little more patience to get the shot.
    I have not used the Nikon 1.4D or 1.8 to compare. I wanted the fastest since this was a lens I would keep, but wish I had tested it before I spent the $450.
  • craig_dcraig_d Registered Users Posts: 911 Major grins
    edited January 15, 2011
    It doesn't sound to me like the people at DxO have any understanding of lens design. Light does not flow in a straight line from the aperture to the sensor, so the quotes about larger apertures leading to more oblique angles of incidence at the sensor are simply inane. Even for wide-angle lenses it wouldn't make sense, because all lenses on SLRs have to place the rear element far enough from the sensor as to not be hit by the reflex mirror when it flips up. Light does not come into an SLR's body at horribly oblique angles, and in any case modern digital sensors have microlenses above each photosite to bring as much light as possible to the sensor. The comments from DxO take none of these facts into account.

    I have used Canon's EF 50mm f/1.4 and f/1.8 lenses. In general I don't find apertures greater than f/2 all that usable, not so much because of reduced sharpness as because of increased spherical aberration and insufficient depth of field. But every once in a while you find yourself in some incredibly dark situation where f/1.4 is the only way to get a reasonable chance at a decent exposure without using a flash.

    The main differences between the Canon f/1.4 and f/1.8 lenses are build quality, autofocus, and bokeh. The f/1.8 (the current II version) is very cheaply made; the f/1.4 is much better. The f/1.4 has a USM autofocus motor and focuses quickly and silently. The f/1.8 does not have USM and focuses somewhat noisily but still reasonably quickly. The f/1.4 does a good job of locking focus even in very poor light, while the f/1.8 tends to get lost in poor light. The f/1.4 has eight aperture blades, giving octagonal bokeh, which are less distracting than the pentagons produced by the f/1.8's five blades. The f/1.8 II is also unpleasant to focus manually because not only do you have to flip the A/M switch, but the focus ring is at the front edge of the lens, is very thin, and has a cheap feel to it. The f/1.4 lets you focus manually at any time and its focus ring feels much nicer. The f/1.4 also has a distance window, which the f/1.8 II lacks.

    There is also, of course, the older, original EF 50mm f/1.8, which you can find used. It is better built than the II version and has a distance window, but is otherwise pretty much the same.

    So for Canon, I think the extra cost of the f/1.4 lens is well worthwhile. I haven't used anyone else's modern autofocus 50mm lenses, so I can't offer an opinion about Nikon, Pentax, etc.
    http://craigd.smugmug.com

    Got bored with digital and went back to film.
  • philtherowerphiltherower Registered Users Posts: 49 Big grins
    edited January 16, 2011
    I think build is something to worry about, but only with the new ones: the old one I just got, which is made in Japan, is half metal build and it feels quite substantial. So if you can find one for a good price, I think it'd be better to go for the 1.8 and buy a wider prime on top of it
  • studio1972studio1972 Registered Users Posts: 249 Major grins
    edited January 16, 2011
    craig_d wrote: »
    It doesn't sound to me like the people at DxO have any understanding of lens design. Light does not flow in a straight line from the aperture to the sensor, so the quotes about larger apertures leading to more oblique angles of incidence at the sensor are simply inane. Even for wide-angle lenses it wouldn't make sense, because all lenses on SLRs have to place the rear element far enough from the sensor as to not be hit by the reflex mirror when it flips up. Light does not come into an SLR's body at horribly oblique angles, and in any case modern digital sensors have microlenses above each photosite to bring as much light as possible to the sensor. The comments from DxO take none of these facts into account.

    It could be that the micro lenses are part of the problem. If light is coming to the sensor from a larger variety of angles (as it would be with a wider aperture) the micro lens may well not direct all of it onto the sensor sight. I think the testers probably do have a good understanding of optics BTW. I agree that the angles should not be very oblique, but they would be more so than with a slower lens.

    Still wand a 50mm 1.2 though.
  • ripbobripbob Registered Users Posts: 41 Big grins
    edited January 16, 2011
    If you're on a shoestring budget, you can't beat the price of the 1.8, but I'd get the mark I for the build quality.
  • JustinThymeJustinThyme Registered Users Posts: 112 Major grins
    edited January 17, 2011
    50 1.4 hands down even over the 50 1.2L
    The 50 1.8 is OK for the extremely budget minded but its plastic build, slow AF and 6 blade aperture leaves a lot to be desired.
    When tossing the build quality aside the AF and difference in bokeh from 6 blade to 8 blade makes a huge difference in IQ.
    The 50 1.2L has a superior build quality but it only tops the other to from f1.2 to f2, after that the 50 1.4 is sharper and past 2.8 both the 1.4 and 1.8 are sharper.
    Canon CPS Gold Member
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