Canon USA
Occasional Contributor
Posts: 5
Registered: ‎11-14-2012

"AF Working Range" & "Metering Range" question

[ Edited ]

I am confused by two technical terms in the camera specs, can anyone please explain the meaning and real life impact to me :-o ?

1. According to the specs, the 6d has an expanded "AF Working Range": "Center AF Point: EV -3 to 18 (at 73°F/23°C, ISO 100)" - see

  • Since afaik all metering is done though the lens, (how) does the max. open aperture of the lens influence this af working range?
  • Since the -2ev of the 5d3 is supposed to be nearly moonlight, does a -3ev rating make a difference for real life shots like darker wedding receptions or shots in dim-lit clubs?

2. The "Metering Range" for the 6d (and 60d btw) is "EV 0-20 (at 73°F/23°C with EF 50mm f/1.4 lens, ISO 100)", for the 5d3 "EV 1-20 (at 73°F / 23°C with 50mm f/1.4 lens at ISO 100)" ....

  • Since a lens with a smaller max. open aperture will bump up the min. ev of the metering range, how does the difference between 5d3 (1-@f1.4) and 6d (0-@f1.4) matter for real life shots say with lenses of a max. open aperture with f2.8 or f4?


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