Deep Hidden Meanings? EOS 6D/3D?

[Flake]

BTW the Canon image is here http://obj.fotosidan.se/obj/docpart/3e/3ed0a5c3decfdbfd917915cb08fec949.jpg

 

[tzalmagor]

The much vaunted low light performance of the D700 is crippled by an autofocus at f/5.6 which gives up way before the 5D MkII with it's more sensitive f/2.8 centre spot.

An f/2.8 spot requires four times more light than an f/5.6 spot in order to work, so wouldn't it be *less* sensitive ?

 

[Flake]

The much vaunted low light performance of the D700 is crippled by an autofocus at f/5.6 which gives up way before the 5D MkII with it's more sensitive f/2.8 centre spot.

An f/2.8 spot requires four times more light than an f/5.6 spot in order to work, so wouldn't it be *less* sensitive ?

Does it? Why? an f/2.8 lens lets in four times more light!

 

[tzalmagor]

The much vaunted low light performance of the D700 is crippled by an autofocus at f/5.6 which gives up way before the 5D MkII with it's more sensitive f/2.8 centre spot.

An f/2.8 spot requires four times more light than an f/5.6 spot in order to work, so wouldn't it be *less* sensitive ?

Does it? Why? an f/2.8 lens lets in four times more light!

As far as I understand, or maybe misunderstand, an f/2.8 spot is one that needs a lens with max aperature of f/2.8 (or wider) to work. That would mean that f/5.6 would not give it enough light to focus, while f/2.8 would.

 

[Flake]

Not quite right, it does need a lens with an f/2.8 aperture to work, but that's partly because the AF system calculates depth of field more accurately. It's also the reason why the Sigma f/1.4 performs worse on a Canon body than it does on a Nikon, which is less affected by the focus shift on stopping down.

The informal tests we did showed quite a bit of difference, as soon as we lost daylight and twighlight went a bit dark the Nikon just wouldn't focus on anything that wasn't under a street lamp, we never did find out where the Canon gave up, it didn't get dark enough!

 

[neuroanatomist]

The much vaunted low light performance of the D700 is crippled by an autofocus at f/5.6 which gives up way before the 5D MkII with it's more sensitive f/2.8 centre spot. A friend & I took both cameras out at night both of them had Sigma 70 - 200mm f/2.8 lenses on, she ended up so frustrated that the Nikon refused to focus lock on anything when the Canon was quite happily managing.

I think this is a misunderstanding of the way the f/2.8 vs. f/5.6 AF points work. There is a certain minimum amount of light an AF sensor needs to achieve a focus lock. From your description, that threshold is higher for Nikon, meaning the Canon can AF in less light than the Nikon. Low light AF performance derives from the sensitivity of the pixels in the AF sensor (usually reported as an EV value). That sensitivity will apply to all of the AF points on the sensor, independent of orientation or whether the sensor is active with f/2.8, f/4, f/5.6, or f/8 light flux.

Canon refers to the center f/2.8-sensitive AF point as 'high-precision' not 'high-sensitivity'. The comments that the f/2.8 sensor is less sensitive are, in a way, correct - those sensors require more light to function, but with that additional light, they are able to deliver a more precise focus measurement. Note that on the 1-series bodies, that high precision center AF point requires f/4 light flux, instead of f/2.8 light flux (i.e. it still requires more light than a f/5.6 point to achieve higher precision, but not as much more as the f/2.8 center points on lower level, non-1-series bodies).

Indirectly, there may be some benefit from the high-precision AF point for low-light AF - the f/2.8 sensor will achieve lock on a subject with lower contrast because it's using more of the available light (even though in absolute terms, it's less sensitive).

 

[mikeeick]

So, what kind of birds are these? Storks? Herons? Cranes? I hope that this isn't about an "egrettable" new camera.

They are Great Egrets. D'oh!

YES, they are. Thank you! Finally one to name these birds right after all these comments with storks, cranes and so on.
(On the original photo there are in fact even some more species to see if you look closely: 3 Spoonbills on the right, 1 Grey Heron and some Grey Geese. No cranes, no storks... Unfortunately all of these birds are covered in the Canon invitation by the orange textbox.)

For all of you who want to learn more about the Great Egret or Great White Egret: http://en.wikipedia.org/wiki/Great_Egret

 

[gmrza]

Sometimes it is right in front of your face....

1. Canon likely has shown a pictures from the advertising for the new camera.

2. Canon always has only photographs taken with the new body except for those photographs of the camera itself.

3. The photograph of the cranes is taken in low light with a very wide angle lens.

4. The only low light wide angle lens is the 16-35 f2.8 and it is only wide angle on a FF body.

Therefore, new camera is FF. Eithere that or they are going to announce a new printer.

Now if I could only count the pixels.....

I doubt the photo was shot with a wide angle lens. At least in my opinion, the photo exhibits some
perspective compression, plus the point of view is almost on top of one of the egrets. You would
need to be standing almost on top of the egret to shoot this with a wide angle. If you did, you would
see perspective distortion from the wide angle. Instead, the perspective is somewhat compressed.
I would say the should was taken with a telephoto, rather than a wide angle... - and I wouldn't
read anything into that either.

 

[able]

I doubt the photo was shot with a wide angle lens. At least in my opinion, the photo exhibits some
perspective compression, plus the point of view is almost on top of one of the egrets. You would
need to be standing almost on top of the egret to shoot this with a wide angle. If you did, you would
see perspective distortion from the wide angle. Instead, the perspective is somewhat compressed.
I would say the should was taken with a telephoto, rather than a wide angle... - and I wouldn't
read anything into that either.

I agree about the telephoto. It's difficult to get close to birds for a wideangle shot unless the photographer sat in a blind and waited for the shot.

Could this be shot with a camera featuring a internal HDR option?