[Recovered Thread: 39066]

[SimonP]

In Imaging-resource's tests a85 is faster than a75 (focusing). Why? Does one megapixel difference have impact on shutter lag?

[JimC]

A variety of factors impact Autofocus Times (lighting levels, amount of contrast in the subject, focal length, focus distance, etc.).

So, when you see Autofocus Times quoted, don't assume that a camera you buy will function identically (chances are, it will be worse insome conditions, compared to the times you see in some tests).

Autofocus Times can even vary with the same camera model, taking photos in the same conditions, simply due to calibration and component tolerance differences.

As close as these models are in Dave's tests, I doubt there would be any real world differences in Autofocus Times.

[Sivaram Velauthapillai]

Has the hardware changed? I haven't checked but maybe the A85 uses the newer DIGIC chip while the A75 uses an older one?? maybe?? :?:

[JimC]

Sivaram Velauthapillai wrote:

Has the hardware changed? I haven't checked but maybe the A85 uses the newer DIGIC chip while the A75 uses an older one?? maybe?? :?

Nah, I don't think so. The A75 even tested faster on some parts of the tests. But, they are close enough that I doubt you'd see any real world difference in Autofocus Lag between them.

It's probably just the way one camera handled his particular focus chart versus the other, in the conditions that they were tested in. In real world conditions, the opposite may occur (too many factors influence Autofocus Speed).

For example, Steve's results with the A75 and A85 were about the same:

A75:

The all-important shutter lag (delay from pressing shutter until picture is actually captured) is about 0.5 to 0.7 seconds, a little faster than average thanks to its robust autofocus system.

http://www.steves-digicams.com/2004_...s/a75_pg7.html

A85:

The all-important shutter lag (delay from pressing shutter until picture is actually captured) is approx. 1/10 of a second when pre-focused and 6/10 of a second including autofocus.

http://www.steves-digicams.com/2004_...s/a85_pg7.html