follow us on FacebookRSS FeedFollow us on Twitter

Auto Focus Testing – Sony A77 vs Canon 5D Mark II in low light @ SonyAlphaLab

"Here’s what you need to know about the auto focus systems and aperture in order for this test to make sense. When slr’s or slt’s like the a77 are trying to focus, the aperture of the lens is always open to widest aperture until the shutter button is pressed. Then the camera then adjusts the aperture to whatever setting you have, and takes the picture.  This all happens in a micro-second as you would imagine.

You may have noticed this about the aperture on some cameras when using the DOF (depth of field) preview button. What that button does is set the aperture to the actual value you have set, hence giving you an accurate depth of field preview."