On 8/11/2012 2:17 PM, Chuck Norcutt wrote:
> I'm glad to hear that there's apparently nothing not understood now.
LOL! There is certainly a universe of stuff I don't understand. :-) I do
understand CDAF a little better now.
> I didn't say anything at the time but when you first posted this "problem"
> I wondered why I could never recall seeing anything similar with either
> my Minolta A1 or Samsung WB650 which both, of course, have CDAF. And,
> in terms of digital technology years, the Minolta is already ancient
> history.
>
> I suppose it should also show the mid-range focusing problem where it
> focuses on whatever shows greatest contrast but not necessarily the
> correct depth.
Not simply greatest contrast, but some combo of level of contrast and area it
covers within the AF area.
The E-M5 has 35 focus areas covering about the same image area as the 11 of the
E-PL1, and so each area is smaller, and
it has fewer problems.
The Sammy doesn't say. There are 45 possible AF point settings, but they
overlap a lot, so the actual area is rather
large. G11 and S100 specs say 9 points, but you can set them to Normal or
Small, and Small covers much less area than
the Sammy AF point(s). Like the Sammy, they can be moved all over the place,
but I never do. :-)
> But perhaps I've never seen that on these small sensor
> cameras with their very large depth of field. Oops. Wait a minute.
> With the Samsung racked out to its 350mm equivalent focal length I do
> sometimes get a mis-focused image. I attributed that to operator error
> but now it occurs to me that, despite the small sensor, depth of field
> is not so great at 350mm equivalent. Still operator error I guess but
> of a different kind than I expected. I'll have to pay more attention to
> where the focus actually lands and why.
I think you are right that it works much as with the Oly live view mirrorless
ILCs, but small sensor DOF makes it less
obvious. The smaller sensor areas on my Canon compacts make them more likely to
focus where I want.
In Focus Moose
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What if the Hokey Pokey *IS* what it's all about?
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