Cytat:
Zamieszczone przez
kichu1979
to nie chodzi o lacznie pomiaru swiatla z aktywnym czujnikiem af, ale o wykorzystanie danych pochodzacych z czujnika ekspozycji przy pracy autofocusa - tryby automatyczne, sledzenie itd. np. Nikonowskie sledzenie 3D, ktore opiera sie na informacji o kolorze podawanej systemowi AF przez czujnik espozycji (1005-polowa matryce RGB), albo tryby Auto Area, gdzie np. o decyzja na co ostrzyc moze byc zalezna od tego czy pucha za posrednictwem czujnika ekspozycji wykryje w kadrze 'skin tones' lub nie i w jakim otoczeniu
Canon implementuje to teraz w 7D - chwalac sie nowym czujnikiem ekspozycji i jego powiazaniem z AF (iFCL)
A wlasnie ze nie :D iFCL oznacza cos innego.
Cytat:
Canon 7D's new AF system is tightly linked to the Metering system, much like recent Nikon systems, and even the concepts are similar; but the uses are not the same.
First the new meter has 63 zones, and they are linked to the 19 autofocus points. Sound familiar? The metering sensor has two layers: the top is sensitive to Red and Green, and the bottom layer to Blue and Green. So it can measure a full spectrum of RGB, rather than just luminosity; and when it compares the data between the AF system and its own color system, the Canon 7D has a better understanding of the image area; not only what colors there are, but what is where.
Nikon uses this same type of data to track objects moving through the image area, augmenting their continuous focus mode. Canon does not.
The color information also becomes important when trying to focus more accurately when shooting under unusual light sources, like sodium lights, whose unusual spectrum often fools AF systems into backfocusing significantly. When light sources like these are detected, though, the Canon 7D can compensate.
A ponizsze z
Cytat:
Like most good ideas, the core of this one is very simple, but that's the nature of most good engineering: If you've identified the subject as being located a certain distance away from the camera, nearby objects that are close to the same distance are most likely part of the subject, too. Thus, rather than simply relying on a spot AE reading centered on the primary AF point, or blindly combining exposure information from a cluster of AE points in some arbitrary geometric grouping around the active AF point, the Canon 7D instead gives stronger weighting to exposure sensor segments that lie beneath adjacent AF points showing a similar distance reading.
