Part of my interest in the A99 stems from the general consensus is that Sony sensors have superior dynamic range to Canon’s sensors. As you will see from my test shots albeit relatively high ISO, the differences are surprisingly minimal.
The test was done with a Sigma 35 on the 6D and the Sigma 50 on the A99. To test the shadows I pushed the Shadow slider in Camera Raw by a full stop and pushed exposure by half a stop. To test highlights retention; leaving the shadow adjustments in place, I dropped the highlight recovery by a full stop. All pics were taken at 1600 ISO- 1/60 shutter speed - F/2 aperture.
First up are the unedited images opened in Camera Raw
Canon 6D Shadows
Sony A99 Shadows
Canon 6D Highlights
Sony A99 Highlights
Conclusion: Comparing the attached pics, the real life dynamic range performance between these 2 sensors is about equivalent. Canon’s sensors have come a long way since the 5DMK2, the shadow banding issues are essentially gone. To my eyes the shadow performance of the 6D is actually better than what I got from my 5DM3. Again, comparing the 6D and A99, dynamic range is not a differentiating factor, if anything just going by this test the 6D is overall slightly better with a small edge going to the A99 in highlight retention.