08-28-2013, 09:37 AM
Thanks for the input,
I agree with your and Canon explanation about advantages of their new system. While such
system offers
1.huge AF cover area - nice feature for video
2.solved/reduced split prism blackout problem – it allows to work with A=11. Nice feature for video
However such advantages should comes at certain cost. In this case I suspect the they reduced the maximum “baseline distance” used in their PD. If this is true – the new system offers the potential of bad AF accuracy esp with fast glass :-)
E.g Canon 10D,20d,30d…..60d offer 2,8 max baseline only for AF central point.
Pro camera
has 2,8 AF area only around image center and they have huge AF sensor
There is no camera that offers baseline distance higher that 2,8. That is why all SLR
suffer somehow with focus accuracy for 1,4 and faster lenses. E.g. Canon and
Nikon specifies very good the AF accuracy with such fast glass. E.g. Canon 1D III+
50/1,2 L
There are some physical lows – You cannot make sharp AF point at image corner with big baseline
/2,8/.
I still puzzling the new canon split focus design - what is the output of such convex desing insted of rounded prism
Theory, theory….. The better way to prove it is to search for real life experience. E.g wait for Dpreview
With Kind Regards,
Miro