@Murphy “ una precisazione : l'accuratezza dell'autofocus non dipende dalla grandezza del sensore. Magari uno legge e pensa che sia così. „
Potresti essere il volontario che approfondisce questo sito che afferma il contrario www.falklumo.com/index.html :
“ 1.3.3. DEFOCUS BLUR
As noted [camera equivalence] , blur due to defocus increases like ~crop^2!
I.e., the effect on effective resolution depending on sensor size s is:
MPfocus = ~s^4
As soon as focus accuracy is up to µm accuracy, equivalent cameras perform the same. The above formula is valid for an AF module which is (basically) shared across bodies, like Nikon D300s and D700; or Pentax K-5 and 645D.
The impact of sensor size on focus accuracy is even stronger than with lens center resolution.
My personal opinion is that the accuracy of focus (both automatic and manual) is the strongest single argument in favour of full frame over APSC.
I.e., the required engineering precision of a 36 MP full frame AF is not more than that of an equivalent 7 MP APSC camera. To cope with that, APSC cameras must simply be stopped down more (in equivalent terms). „
L'autore di LumoLabs è un imprenditore tedesco con un un PhD in fisica teorica (come Angela Merkel, per intenderci). È rigoroso come quasi tutti i fisici, ma IMO non ha il dono della chiarezza