Loxia 21 f/2.8 vs. SEL1635Z

Discussion in 'Sony Alpha E-Mount Lenses' started by WoodWorks, Jun 24, 2016.

  1. WoodWorks

    WoodWorks Super Moderator Subscribing Member

    Dec 12, 2012
    Ashland, OR, USA
    Here is a comparison between the Loxia 21mm f/2.8 and the SEL1635 f/4.

    The Scene:

    There wasn't a significant difference between the center of the images, so I'm just posting the upper right and lower left corners. These were manually focused on the knot on the tree in the center of the frame. All are shot with my A7II, on a sturdy tripod with the IBIS turned off, and a 2-sec. timer on the shutter.

    The Loxia is on the left, and the 16-35 on the right.

    Upper right at f/4
    UR F4.jpg

    Lower left at f/4
    LL F4.jpg

    Upper right at f/5.6
    UR F5.jpg

    Lower left at f/5.6
    LL F5.jpg

    Upper right at f/8
    UR F8.jpg

    Lower left at f/8
    LL F8.jpg
    • Informative Informative x 4

    DYNOBOB TalkEmount Regular

    Feb 9, 2016
    Cincinnati, OH
    The zoom looks equal (better?) in UR, I wonder what accounts for LL? Do you see yourself keeping the 16-35?

    Last edited: Jun 25, 2016
  3. Jefenator

    Jefenator TalkEmount Top Veteran Subscribing Member

    Nov 23, 2012
    Oregon, USA
    Thanks for sharing!
    I wonder if field curvature might be factoring in - the zoom compares pretty well in the more distant corner once it's stopped down. (Or there might be decentering - that other corner does seem a bit weak, and come to think of it, that doesn't really look like OOF to my eyes...)
    FWIW my default landscape aperture setting on full-frame is f/11.
    I've been leaning toward the Loxia for size but those more useable wider apertures might really tip the scale.
  4. addieleman

    addieleman Passionate amateur Subscribing Member

    Nov 13, 2012
    Ad Dieleman
    Thanks from me too!

    Lloyd Chambers shows that field curvature is apparent at smaller apertures like f/8. Certainly could be the reason why the lower left corner of the Loxia is sharp despite being much closer than the focus point. Judging from the upper right corner the two lenses are remarkably close once the zoom is stopped down a bit.
  5. WoodWorks

    WoodWorks Super Moderator Subscribing Member

    Dec 12, 2012
    Ashland, OR, USA
    I'm pretty sure the reason the lower left is softer is because of the slope in the landscape. The left side is closer to the camera than the right. Here are both lower corners at f/4, the 16-35:


    And the 21:


    They both show the same deviation. But the 21 clearly does a better job in the corners.
    • Informative Informative x 2
  6. WoodWorks

    WoodWorks Super Moderator Subscribing Member

    Dec 12, 2012
    Ashland, OR, USA
    Oh yeah. There will be plenty of times when I'll want to go out with the 16-35 / 24-240 combo instead of my primes. Horses for courses, as they say.
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