In this auto focus comparison with the Sony A77, A580, and Canon 5D mark II, I’m going to see what these cameras can do in low light with little to know contrast. Last time I did this test it was quick and not the most thorough. This time I set up the the “lab” a little better with three different contrast points on the box, and then just the low contrast card board itself. I also put a clear ornament box to the right just to see what happens with that.
Check this out, and please fire away if you have any questions or comments!
The Bottom line with the AF:
The Autofocus on all three cameras performs very well. Not surprisingly the ~$2200 5D Mark II does the best on plan cardboard, with the ~$2000 A77 doing almost as good. The A580 performed about the same as the A77 on the cardboard, but its not equipped with an AF Illuminator like the A77. It relies on the flash for this, and I did not use that.
I hope you guys got something out of my efforts here, and thanks for your patience. As I continue to learn and review some of the best equipment available today for photographers, I’m going to hit a road block here and there. Often these simple “lab” type test will prove which camera, lens, or equipment performs best in a given situation. In this case, poor lighting a low contrast subjects 
Firmware Upgrade Fixed this issue considerable on the Sony A77!! Get it here >>
Your support is greatly appreciated as we run this site in our spare time and are not paid. We can however, make a small commission if you click a product link that your interested in. That click will then give us credit if you choose to purchase any given item. This has no effect on the cost of the product, and is a simple way to give back to SonyAlphaLab.com for the effort and info we provide.
Also, be sure to keep following us on Google+, Twitter, RSS-feed, or Sign up for Email Updates!!
Direct Shopping Links – Thanks for your Support!!
BHPhotoVideo | Amazon – US, CA, UK | Adorama | Ebay – US, CA, UK, DE, FR, ES
Thanks,
Jay
About the Author
Loading ...
Regarding the a580: why Face Detection turned on while focussing on a box?
I forgot to turn it off
Sorry about that.
LOL. Maybe it makes a big difference.
By the way, how did you manage to get the live histogram?
It made absolutely no difference last time I tested it, but I still wanted it off for this test regardless. As far as the live histogram on the A77 goes, you need to cycle through the lcd display modes by pushing the display button on the back a few times.
Best,
Jay
Tested mine as well and Getting the same result as yours.
Thanks for the comments Sky
Sorry, I meant the a77 histogram.
Thank you for the answer, Jay. Have a nice sunday.
would it be the 5D2 is using Contrast detection during Live view? VS Phase detection on the A77?
my understand is that Contrast detection is more accurate but just slower?
Phase vs contrast… not only that it’s faster…
while using cotrast detection, Your AF engine has to overshoot when it’s looking for best contrast, than after passing best contrast distance and loosing it, it goes back to the highest contrast measured distance …
phase detection just has the “right” distance… the beam is launched, it comes back to the camera, and the camera knows the right distance… no searching or “sniffing” for the highest contrast…
Cadam,
Thanks for the comments and sharing the info on Phase vs contrast! I did not know that the phase needs the beam or that the contrast worked that way. Makes sense!!
Thanks,
Jay
Thanks Frank!
I think your correct, but Matt’s info about the AF sensors being larger and the huge advantage of light seems to be more of a factor in this particular random scenario I created for a focus test.
Thanks for the comments!
Jay
I found both videos interesting.
Why not compare to “the best” – specially as the specs says the A77 should be better than 5D.
Also – even if the “mirror free” a77 is using just 30% of the light, it still should be better (compared to specs).
I find it a fair thing to test these cams against eachother on these conditions, and as Jay I wonder a bit why “all this new technology” seemes to lack compared to some “elder” ones..
regards
Chris
Thanks for the comments Chris
Jay