« on: Today at 09:37:38 AM »
Can someone please explain dumb me what does focus at "-3ev" actually mean? Thanking in advance.
Exposure values were initially used to merely compare exposure settings, and settings independent of film speed. EV0 was defined as 1sec at f/1. In this context, it is assumed to be at 100ISO (ISO100, aka light value). EV0 light would require f/1 at 100 for 1 second or equivalent to properly expose. EV-3 is three stops darker, or f/1 at 100 for 8 seconds, or f/0.7 at 200 for 2 seconds, etc. In other words, it's dark.
Thx much. So 6d center point would focus better in low light?
As per the theory, yes.
However, I find that EV3 is the extreme of low light and I'm not sure what can be shot handheld.
I'm sure AF at EV-3 is useful to some people, but as far as I'm concerned I don't shoot too often in extreme low light. When I do, I (a) use the tripod and AF is pretty much irrelevant; OR (b) use AF assist with a speedlite.
PS: I'm sure someone will come along denouncing me for not trying the AF at EV-3, but personally, I haven't found it too useful. I'm also yet to be faced with a situation where my 6D could achieve AF and the 5D3 could not.