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You are here: Home / The Last Word / 18/3.8 Super-Elmar corner smear with a7R & a7RII

18/3.8 Super-Elmar corner smear with a7R & a7RII

August 12, 2015 JimK 2 Comments

We’ve seen in the two previous posts that the Sony a7RII does wonders for the color casts that beset the a7R when used with short, pseudo-symmetric rangefinder lenses. Since the sensor stack is still the same thickness, I don’t expect any improvement in corner smear, but it’s certainly worth testing.

I attached a Leica 18mm f/3.8 Super-Elmar-M ASPH to each camera and made an aperture series of this scene, shown at f/8:

a7RII
a7RII
a7R
a7R

Both images were developed in Lightroom with daylight white balance. The actual balance is quite different even in the center of the image. The greater falloff of the a7R and the magenta corner casts are evident.

Checking the center at 300% magnification:

a7RII
a7RII
a7R
a7R

Similar sharpness.

Now the lower left corners, with a one-stop boost in exposure.

 

a7RII, f/3.8
a7RII, f/3.8
a7R, f/3.8
a7R, f/3.8

The a7RII is maybe a hair better. It could be my imagination.

a7RII, f/5.6
a7RII, f/5.6
a7R, f/5.6
a7R, f/5.6

Sharpness is about the same.

a7RII, f/8
a7RII, f/8
a7R, f/8
a7R, f/8

Same sharpness.

a7RII, f/11
a7RII, f/11
a7R, f/11
a7R, f/11

Same sharpness.

a7RII, f/16
a7RII, f/16
a7R, f/16
a7R, f/16

Same sharpness.

I’d show you color cast pictures through the Expodisc, but the lens front element prevents using the Expodisc with the hood off, and the hood prevents getting the Expodisc close enough to the lens.

 

The Last Word

← 24/3.4 Elmar color casts with a7R & a7RII 24/3.8 Elmar corner smear with a7R & a7RII →

Comments

  1. Bert Hensen says

    August 14, 2015 at 10:14 pm

    Jim,
    I understood the A7rII has an 18Mp APS-C mode.
    Do we still have anything to complain about regarding corner smearing, color cast and vignetting shooting the more difficult rangefinder lenses in this mode? Except for less pixels and the crop factor.

    Reply
    • Jim says

      August 15, 2015 at 7:53 am

      I suspect that will get rid of vast majority of the corner smear. Unfortunately, I have dropped and damaged by worst-case corner smear lens, the 28/2.8 Elmarit-M ASPH. I do have the pictures for the last runs, and I can do some crops and look at them. Right now my plat is quite full, though.

      Reply

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