03-18-2011, 01:19 PM
[quote name='Klaus' timestamp='1300449572' post='6929']
What you showed us was a comparison of two different camera (which is fine) with two different lenses (which is not fine).
Sony 70-200G:
"It is fast (although not as fast as in the Zeiss ZA 24-70mm f/2.8), near silent and very accurate. "
Canon 70-200/4L IS:
"The lens features a ring-type USM drive resulting in a near silent and very fast AF."
"fast" vs "very fast" just to highlight the important words here. That's a subjective comment to some degree but obviously yours does also qualify as such.
A while ago we discussed internally how to come to a definitive conclusion regarding the DSLR AF capabilities. Technically you require identical lenses with identically capable lens firmware (which is already a no go) under identical lighting conditions (which means indoor).
The only relatively meaningful lens for a more formal test would be a Sigma 70-200/2.8 HSM II which is available on all platforms.
Regarding the indoor test scene - our discussion ended when considering taking pictures of a Merklin train approaching the camera. :-)) Technically this may be even fine to some degree though. However, we dropped the idea because it isn't really reflecting a typical field scene which would be a point of criticism, of course.
In our opinion such burst shot comparisons are a waste of resources because you can't keep the set of parameters valid enough.
[/quote]
The Sony 70-200mm f2.8 G is the best the Sony platform has to offer in this area. The 70-200mm f4 L USM is not... both the f4L IS USM and f2.8L IS USM II are noticeably faster.
If it is true, that the Sony 70-200mm f2.8 G SSM is slower (how do we know that? The camera has a big influence on how fast a lens focusses too.. my 450D is slower in focussing than a 7D or an 1D for instance), that then again does not make the A55v (the one in that "test" from IR) very good at tracking, its lens being ones of the things that hold it back.
Even if the 70-200mm f4 L USM is faster, it is still mounted on my 450D, with less light and at a closer distance. And the shots still are better in focus on the whole.
I would not say that my 450D is better than average suited for sports photography, though.
You can not use a 3rd party lens and think you level the playing field, lens wise, either. The firmware of the lens will be different for each mount, and for some mounts it may be more "compatible" than others, like you mention yourself.
If you assess cameras and their tracking ability, in whatever scenario, you will have to pick a good lens for each platform, even if that means that for one platform the lens is better than the other. That is what it is about, of course, testing the camera with a mounted lens.
So, yes, there were differences...
- The distance reported by IR was not the real distance, which made me end up shooting the car closer by. Advantage for the A55v here.
- I shot very late in the day, sun was low and covered. And back lit the scene/cars. Advantage for the A55v/IR test.
- I used a f4 lens, not an f2.8 lens. This means that my camera did not use its f2.8 high precision sensor.
So, still, when not everything was the same (In fact,. the only thing that really was the same was the subject (car) traveling towards the camera at approximately the same speed), my 450D with lens seems to cope better tracking the subject in this particular scenario.
Of course, it may well be that the IR "reviewer" was even less capable than me, and completely ruined the A55v + 70-200mm f2.8 G shoot. And that that is the reason for the not so great results in that not very taxing test.
It might even also be possible that the A55v reviewer from dpreview was using the camera all wrong, making him come up with a wrong conclusion of the AF tracking capability.
What you showed us was a comparison of two different camera (which is fine) with two different lenses (which is not fine).
Sony 70-200G:
"It is fast (although not as fast as in the Zeiss ZA 24-70mm f/2.8), near silent and very accurate. "
Canon 70-200/4L IS:
"The lens features a ring-type USM drive resulting in a near silent and very fast AF."
"fast" vs "very fast" just to highlight the important words here. That's a subjective comment to some degree but obviously yours does also qualify as such.
A while ago we discussed internally how to come to a definitive conclusion regarding the DSLR AF capabilities. Technically you require identical lenses with identically capable lens firmware (which is already a no go) under identical lighting conditions (which means indoor).
The only relatively meaningful lens for a more formal test would be a Sigma 70-200/2.8 HSM II which is available on all platforms.
Regarding the indoor test scene - our discussion ended when considering taking pictures of a Merklin train approaching the camera. :-)) Technically this may be even fine to some degree though. However, we dropped the idea because it isn't really reflecting a typical field scene which would be a point of criticism, of course.
In our opinion such burst shot comparisons are a waste of resources because you can't keep the set of parameters valid enough.
[/quote]
The Sony 70-200mm f2.8 G is the best the Sony platform has to offer in this area. The 70-200mm f4 L USM is not... both the f4L IS USM and f2.8L IS USM II are noticeably faster.
If it is true, that the Sony 70-200mm f2.8 G SSM is slower (how do we know that? The camera has a big influence on how fast a lens focusses too.. my 450D is slower in focussing than a 7D or an 1D for instance), that then again does not make the A55v (the one in that "test" from IR) very good at tracking, its lens being ones of the things that hold it back.
Even if the 70-200mm f4 L USM is faster, it is still mounted on my 450D, with less light and at a closer distance. And the shots still are better in focus on the whole.
I would not say that my 450D is better than average suited for sports photography, though.
You can not use a 3rd party lens and think you level the playing field, lens wise, either. The firmware of the lens will be different for each mount, and for some mounts it may be more "compatible" than others, like you mention yourself.
If you assess cameras and their tracking ability, in whatever scenario, you will have to pick a good lens for each platform, even if that means that for one platform the lens is better than the other. That is what it is about, of course, testing the camera with a mounted lens.
So, yes, there were differences...
- The distance reported by IR was not the real distance, which made me end up shooting the car closer by. Advantage for the A55v here.
- I shot very late in the day, sun was low and covered. And back lit the scene/cars. Advantage for the A55v/IR test.
- I used a f4 lens, not an f2.8 lens. This means that my camera did not use its f2.8 high precision sensor.
So, still, when not everything was the same (In fact,. the only thing that really was the same was the subject (car) traveling towards the camera at approximately the same speed), my 450D with lens seems to cope better tracking the subject in this particular scenario.
Of course, it may well be that the IR "reviewer" was even less capable than me, and completely ruined the A55v + 70-200mm f2.8 G shoot. And that that is the reason for the not so great results in that not very taxing test.
It might even also be possible that the A55v reviewer from dpreview was using the camera all wrong, making him come up with a wrong conclusion of the AF tracking capability.