When did big become bad?

Started Jul 20, 2010 | Discussions thread
Great Bustard
Forum ProPosts: 23,497
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Re: im here to remind you
In reply to Rriley, Jul 25, 2010

Great Bustard wrote:

Now, just how is the camera supposed to know what I want to focus?

Rriley wrote:

what better way than a wide distribution of focus points

Totally agree, but with the following qualification:

What better way than a wide distribution of accurate and precise focus points

But this qualification is largely unnecessary, of course, if we're talking about photos where the whole of the scene is within the DOF.

if you cant trust your AF deep DoF photography from your camera, you have to make a judgement as to how much speed you want to sacrifice by going to another aperture setting. The totality of it can mean that you will inordinately raise ISO, conceding noise and DR

Again, I'm a bit confused. I've never had difficulty with accurate AF for a deep DOF scene. My difficulties with AF have come from using outer AF points in low light at extremely shallow DOFs.

But, let's consider the following scenario -- you have a lens with strong field curvature and you want to focus closely with the subject near a corner, but no AF points nearby, and the DOF you're shooting is not nearly enough to cover the error from a "focus and recompose" technique.

Well, that field curvature must be pretty strong to go make focus and recompose from the nearest AF point still a problem. However, I have to say that's a pretty unique shooting situation, no?

Still, if those are the types of photos you take, then, for sure, the FF AF scheme is not your friend.

Not any mode, actually. I'd be pretty disappointed if I got an image that was sharp corner-to-corner in Av mode when I selected f/1.2.

sure, you want to be able to shift AF points to where your desired focus point is, even if its in the corner or edge. That will take a wider AF array than we see right now on FF

Absolutely. As I said in an earlier post, there are times that it's an issue for me. Shoot, just making the AF diamond an AF rectangle would help out a lot.

Indeed, there are many limitations to compacts. But, if the rumor of Nikon's 4x mFT-like camera materializes, then, dare I say, that may well be the system that you and others would really sing the praises over (assuming, of course, that unlike mFT, corner sharpness is not an issue).

good luck with those assumptions

To be honest, I was surprised to see the poor corner performance of mFT lenses. The Sigma DP1 and DP2 are stellar, as are many, if not most, compacts.

we're way ahead of you there
http://forums.dpreview.com/forums/readflat.asp?forum=1022&thread=35878188

Andy Westlake does not attach the importance to corners that many in this forum do, with the Panasonic 45 / 2.8 macro review being one example.

P.S. For Tyrone: so long as the gulls remain subsonic, it's not an issue.

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