AF System

[Dolby]

Just when I thought I was getting to grips with AF and the greater number of points, I now see there are different types of points :/

Is cross hair AF that much better than a dot or line?

 

[MadMailMan]

What camera have you got? My Canon only uses the dor AF if the lens is f/2.8 or wider. The cross hair is normal. I would think Lline would be usefull if you are trying to shoot something moving that would make a straight line passed your position. So I guess what I'm trying to say is it all depends on what you are shooting.

 

[fwwwn]

Have a look at this page. It's outdated, but explains it well. Cross-type is merely two line-type sensors intersecting each other, arranged like a '+' or an 'x'. This allows that specific point to focus on horizontal or vertical edges/objects more accurately/quicker. The center point cross-type AF in most recent Canons is extra sensitive at f/2.8 or faster, but still works normally up to f/5.6.

 

[koffiejunkie]

I'm pretty sure both my 40D and 50D's manuals say all 9 focus points are cross type at f/5.6, and the center point is additionally sensitive (three lines intersecting instead of two) at f/2.8.