Monday, February 02, 2015

Sony A6000 - a seven lens comparison

It seems that I'm still on a roll.

Since I already had the test setup in place, why not compare some more of my manual focus lenses against the modern Sigma EX DN E autofocus using the Sony A6000?  Why not look at the center of the scene as well as an extreme edge?  I'm retired and have nothing better to do, right?

Scene setup ~ Sigma f/2.8 30mm at f/4

The comparison setup didn't change.
  • Sony A6000 camera, ISO100, "A" mode, "standard" image style settings, shot in RAW format
  • Big sturdy Manfrotto tripod
  • RAW images converted to jpg at 100percent quality using Sony's software - no image adjustments were made at the time of conversion
  • 600x600pixel segments were taken out of each file - no adjustments to the image were made during the cut/paste process
The following two comparison files are quite large.  So click on them and they'll take you to Flickr where you can download and view the full-rez images.

Sony6000-  Seven Lens scene center Comparison

Sony6000-  Big Lens scene edge Comparison

My comments on these comparisons should be obvious.  The new Sigma 19mm, 30mm, and 60mm (not shown here) f/2.8 EX DN E/Art lenses are incredible from wide open all the way across the field to the very edges of the frame.  These are "keepers".

I think I can see where the old Nikkors have a few challenges, even on the smaller than full frame APS-C sized sensors.  I'm not sure why the edges fall off as badly as they do when the lenses are shot wide open, but they're pretty obviously bad.  My conjecture is that either the lenses were designed for speed and resolution at the center (which is common for designs of that period), and/or there is a fair amount of field curvature that is throwing the edges of the frame out of focus in these 2D scene comparisons.

No comments: