09-19-2010, 04:46 PM
[quote name='evilthought' timestamp='1284913675' post='2924']
And I explained to you why it's not gimmicky. There are many situations where you can use 7 fps without need for continous AF, like here
![[Image: 7fps-lorikeet-6400-160th-70300-210-6p3.jpg]](http://www.photoclubalpha.com/wordpress/wp-content/uploads/2009/11/7fps-lorikeet-6400-160th-70300-210-6p3.jpg)
Besides, you can always release the shutter button and press it again and the camera will AF again with first shot again.
That's outright nonense. You claim to know that without ever even touching the A55/A33. According to IR review, A55/A33 AF tracking matched that of 7D in their tests (and A55/A33 do have AF in 10/7 fps modes).
[/quote]
If you claim it is nonsense, go complain to dpreview (who actually REALLY tested the AF tracking performance).
We read:
"[color="#8B0000"]On paper, the SLT A55 should be an ideal tool for shooting fast action. It can shoot at 10fps with continuous autofocus. The A55 also has a trick up its sleeve that even the Canon EOS-1D Mark IV cannot match - because its mirror is fixed, the AF sensor can operate full-time, without interruption. This should ensure more accurate continuous AF performance, since the camera is constantly being fed data with which to make the necessary calculations.[/color]"
Then we read:
"[color="#8B0000"]That's the theory, but unfortunately it isn't born out in practice. We have found that when presented with fast moving subjects (we shot a range of subjects, including cyclists on a track), focus accuracy is far from 100%. In 10fps mode it is clear that the A55's AF system is simply unable to predict subject position accurately when presented with fast-moving subjects at relatively close range, and in a typical sequence of images of cyclists on a track, whilst the zone of focus shifts from frame to frame, it is almost always slightly behind the intended subject.[/color]"
We continue to read:
"[color="#8B0000"]Even when it finds its mark, the A55's auto exposure/ISO system (which is set by default and cannot be adjusted in 10fps mode with continuous AF enabled) appears to be using a simple 1/focal length calculation to determine the ideal shutter speed. This is fine for eliminating camera shake but is not always fast enough to freeze fast-moving action (which is what many people will be trying to do with 10fps bursts).[/color]"
"I[color="#8B0000"]n our shooting, we've found that in good light, at the long end of a 70-400mm lens, the A55 will aim for as low an ISO sensitivity setting as possible - typically sets a shutter speed of no higher than 1/500sec. This is fine for static subjects, but not always fast enough to ensure sharp images of a fast-moving cyclist or soccer player, even if the AF is accurate.
If you want to take control over exposure but still shoot fast bursts it is necessary either to switch to single-servo AF or leave the dedicated 10fps setting and select continuous shooting (6fps or 3fps) in one of the other exposure modes.[/color]"
No, it is not a good implementation. Why you keep insisting it is great, I am not sure. Might it be that you have a Sony, and feel compelled to defend it, no matter what?
To me that A55v 10fps mode (and 6fps mode in lesser degree) is not something desirable. Better get a 60D, D7000, 7D or D300s if a fast burst mode is needed.
And I explained to you why it's not gimmicky. There are many situations where you can use 7 fps without need for continous AF, like here
Besides, you can always release the shutter button and press it again and the camera will AF again with first shot again.
That's outright nonense. You claim to know that without ever even touching the A55/A33. According to IR review, A55/A33 AF tracking matched that of 7D in their tests (and A55/A33 do have AF in 10/7 fps modes).
[/quote]
If you claim it is nonsense, go complain to dpreview (who actually REALLY tested the AF tracking performance).
We read:
"[color="#8B0000"]On paper, the SLT A55 should be an ideal tool for shooting fast action. It can shoot at 10fps with continuous autofocus. The A55 also has a trick up its sleeve that even the Canon EOS-1D Mark IV cannot match - because its mirror is fixed, the AF sensor can operate full-time, without interruption. This should ensure more accurate continuous AF performance, since the camera is constantly being fed data with which to make the necessary calculations.[/color]"
Then we read:
"[color="#8B0000"]That's the theory, but unfortunately it isn't born out in practice. We have found that when presented with fast moving subjects (we shot a range of subjects, including cyclists on a track), focus accuracy is far from 100%. In 10fps mode it is clear that the A55's AF system is simply unable to predict subject position accurately when presented with fast-moving subjects at relatively close range, and in a typical sequence of images of cyclists on a track, whilst the zone of focus shifts from frame to frame, it is almost always slightly behind the intended subject.[/color]"
We continue to read:
"[color="#8B0000"]Even when it finds its mark, the A55's auto exposure/ISO system (which is set by default and cannot be adjusted in 10fps mode with continuous AF enabled) appears to be using a simple 1/focal length calculation to determine the ideal shutter speed. This is fine for eliminating camera shake but is not always fast enough to freeze fast-moving action (which is what many people will be trying to do with 10fps bursts).[/color]"
"I[color="#8B0000"]n our shooting, we've found that in good light, at the long end of a 70-400mm lens, the A55 will aim for as low an ISO sensitivity setting as possible - typically sets a shutter speed of no higher than 1/500sec. This is fine for static subjects, but not always fast enough to ensure sharp images of a fast-moving cyclist or soccer player, even if the AF is accurate.
If you want to take control over exposure but still shoot fast bursts it is necessary either to switch to single-servo AF or leave the dedicated 10fps setting and select continuous shooting (6fps or 3fps) in one of the other exposure modes.[/color]"
No, it is not a good implementation. Why you keep insisting it is great, I am not sure. Might it be that you have a Sony, and feel compelled to defend it, no matter what?
To me that A55v 10fps mode (and 6fps mode in lesser degree) is not something desirable. Better get a 60D, D7000, 7D or D300s if a fast burst mode is needed.