libertyranger said:
Okay, I've spent some time researching this tonight, but I'm still not too sure. So how is this cross type AF point on the 6D different from the cross type AF point on the 5DII or T3i?
The 5DII and T3i have a center point with one horizontal f/2.8 line and one vertical f/5.6 line - that makes the cross. The f/2.8 line is more accurate, but only works with vertically-oriented features. Worth noting is that all of the 39 cross-type points on the 1DIV are this type, too. for this type point, it's a cross
only with an f/2.8 or faster lens (and only half f/2.8-accurate), with an f/4 or slower lens, it's just a single vertical line (although there are f/4 exceptions on the 1-series).
The 1D X, 5DIII, 7D, 40-60D, and T4i have a dual cross center point - an f/5.6 cross in a '+' shape with and f/2.8 cross in an 'x' superimposed. This point type is fully cross type with any lens down to f/5.6.
The 6D center point has an f/5.6 cross in a '+' shape with a single f/2.8 horizontal line '-' superimposed. It behaves like the first type (5DII etc.) with an f/2.8 or faster lens, but is better in that it remains cross type down to f/5.6.
Hope that clarifies.