"EV" means exposure value, and is an indication of the amount of light. The system was developed by a German photographer and shutter maker named Friedrich Deckel in the 1950s. At any given exposure value there are a number of ISO, aperture, and shutter speed combinations, known as equivalents, that will give the same exposure.
EV -3 is pretty dim, and many cameras' autofocus systems will not be able to lock onto a subject with so little light; so the 6D's AF capability in low light is pretty astounding. It would be great for wedding and event photographers, and anyone doing a lot of existing light photography.
For an idea of how dim EV -3 is, if you were using an f/1.4 lens at ISO 100 you'd need a shutter speed of 15 seconds. It's about as much light as a moonlit night.
The regular AF sensors work by locking onto areas with distinct patterns and comparing the phase shift as they rack focus. (Live View Focus uses a different method, Contrast Detection.) "Cross-type" sensors can work with either vertical or horizontal lines on subjects, making them more accurate with a variety of subjects.
BrianO wrote:
"EV" means exposure value, and is an indication of the amount of light. The system was developed by a German photographer and shutter maker named Friedrich Deckel in the 1950s. At any given exposure value there are a number of ISO, aperture, and shutter speed combinations, known as equivalents, that will give the same exposure.
EV -3 is pretty dim, and many cameras' autofocus systems will not be able to lock onto a subject with so little light; so the 6D's AF capability in low light is pretty astounding. It would be great for wedding and event photographers, and anyone doing a lot of existing light photography.
For an idea of how dim EV -3 is, if you were using an f/1.4 lens at ISO 100 you'd need a shutter speed of 15 seconds. It's about as much light as a moonlit night.
The regular AF sensors work by locking onto areas with distinct patterns and comparing the phase shift as they rack focus. (Live View Focus uses a different method, Contrast Detection.) "Cross-type" sensors can work with either vertical or horizontal lines on subjects, making them more accurate with a variety of subjects....Show more →
Thanks for the clear explanation!
For comp arising, do u also know the EV's of other camera's autofocus? For example the 5D3 and 30D?
When I tested the 6D, Canon offered a darkened cave beside the (photokina) booth.
I did a test shot with 50mm 1.4 at ISO 12.800 (as far I remember). I did not really recognize any motive, just realised some less darker spots I targeted upon. The AF grabed immediatelly without any hunting and I did the picture. Watching the screen I recogniced I was shooting something like a collection of boxes glued to the "caves wall" and zooming into the picture I could read the text printed on them! It looked razorsharp (in focus). That felt mind blowing (my mind, of course ).
There is another element other than just EV - it's the general effectiveness of the focus system and whether a point is cross or non cross (or dual cross in the 5d3/1dx AF system).
I've never really believed the 5dii's (centre point) AF system was effective in particularly dark conditions. It was "OK".
When I tested the 6D, Canon offered a darkened cave beside the (photokina) booth.
I did a test shot with 50mm 1.4 at ISO 12.800 (as far I remember). I did not really recognize any motive, just realised some less darker spots I targeted upon. The AF graped immediatelly without any hunting and I did the picture. Watching the screen I recogniced I was shooting something like a collection of boxes glued to the "caves wall" and zooming into the picture I could read the text printed on them! It looked razorsharp (in focus). That felt mind blowing (my mind, of course )....Show more →
PhilDrinkwater wrote:
There is another element other than just EV - it's the general effectiveness of the focus system and whether a point is cross or non cross (or dual cross in the 5d3/1dx AF system).
I've never really believed the 5dii's (centre point) AF system was effective in particularly dark conditions. It was "OK".
Maybe Ralph is correct about the 6D. It just may be a truly outstanding camera at about 2K; price most surely to settle lower. It has piqued my interest in this camera.
WesN wrote:
Canon Museum says 5DII is -0.5 (obviously the center point), no mention of the outer points.
In my opinion, I doubt they go as low as -0.5 EV. I believe 6D is the first camera ever that Canon reveals the sensitivity of the outer focus points that are not cross-type. One test that I'd like to do if I could get my hands on both 5D2 and 6D is to test them side-by-side on the performance of the outer focus points. If they have the same sensitivity, I guess we're all screwed by Canon, big time.
And yes, the outer points are no cross-type, but in my experience they worked very fine compared to those in my 5D II. I did this test on photokina, Wahoowa, even it was quick and basic.
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