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p*********r
发帖数: 4593 | 1 Here is a set of video showing the auto focus performance for the 7
mirrorless cameras.
http://dc.pconline.com.cn/pingce/evil/1211/3085571_5.html
EM5/GX1/V1 are faster than others. | e**n
发帖数: 5876 | 2 看了一下, EPL5和GX1最快. J2次之. J2对焦有明显的拉近拉远找焦点的过程. EPL5和
GX1就几乎没有.
【在 p*********r 的大作中提到】
: Here is a set of video showing the auto focus performance for the 7
: mirrorless cameras.
: http://dc.pconline.com.cn/pingce/evil/1211/3085571_5.html
: EM5/GX1/V1 are faster than others.
| w*********g
发帖数: 10097 | 3 这个测试结果并不能支持你说v1的对焦远超同济的理由阿：
发信人: playForever (playForever), 信区: PhotoGear
标 题: Re: 现在微单比较好的型号是什么？
发信站: BBS 未名空间站 (Mon Mar 11 14:54:28 2013, 美东)
The best part for V1/J1 or whatever Nikon 1 system models is
its fast autofocus, especially continuous auto focus. Its continuous auto
focus is as good those $2000-3000 level DSLRs.
EM5 is good at high ISO picture quality, but continuous auto focus sucks,
only is good at taking still subject photos. Not good for the moving
subjects and not good for video recording.
【在 p*********r 的大作中提到】
: Here is a set of video showing the auto focus performance for the 7
: mirrorless cameras.
: http://dc.pconline.com.cn/pingce/evil/1211/3085571_5.html
: EM5/GX1/V1 are faster than others.
| p*********r
发帖数: 4593 | 4 Go read dpreview for the GX1 review(attached in the following)
GX1 and EM5 have the same problem of continuous auto focus.
V1 sets new performance bar in term of continuous auto focus for the
mirrorless system. The main reason for the V1 having fast continuous auto
focus is it has phase detection in addition to the constrast detection AF.
Sony NEX-5R and NEX-6 also have both(hybrid detection), but somehow Sony
didn't do good job(no major improvement in auto focus).
--------------Copy from the dpreview for GX1--------------------------
AFC tracking
When set to AFC mode (continuous autofocus) the GX1 employs its contrast-
detection AF to track the subject. Based on the tracking performance of
previous G-series models we were not expecting miracles here, and our
experience of shooting has proven that our caution is justified. Results
were on par with what we experienced with the Panasonic Lumix DMC-G3.
We found the GX1's AFC tracking to be most successful in well-lit scenes
with subjects of strong contrast that move rather consistently. When panning
the camera in order to keep the subject relatively close to the central
area of the viewfinder/LCD screen, we were only able to reach success rates
as high as 50% with very slow moving subjects. In and of itself, we feel
that AFC tracking on the GX1 is a reasonable option as long as you set your
expectations accordingly. Yet, with the introduction of the Nikon 1 V1 and
its benchmark setting AF tracking capability, the GX1- like most other
mirrorless and even entry-level DSLRs - is now looking up at a new standard
of performance.
--------------------------------------------------------------------------
-------------------------Copy from dpreview for the EM5--------------------
Autofocus speed / accuracy
Olympus claims that the E-M5 offers the fastest autofocus in the world when
paired with the 12-50mm F3.5-6.3 lens (at least for for single focus
acquisition), and we have little reason to doubt that. The focus is near-
instant in good light and only drops off in very low light. Being based on
contrast detection (that directly assesses the sharpness of the image),
there's little reason for concern about accuracy - a principle borne-out by
the hundreds of correctly-focused images we've taken.
However, despite Olympus' claims about improvements in continuous autofocus
and subject tracking capability, we found the system too slow and
unpredictable to develop much enthusiasm about. If you're careful about
making sure the camera has locked onto a subject, you can expect to get a
couple of sharp shots out of a burst but the results are patchy and, for the
kinds of 'grab the moment' shooting you'd want it to work for, the results
simply aren't reliable enough. The EM-5 is far from unusual in this respect
(Continuous AF isn't a strength of contrast-detection AF), but for such an
expensive model, and one for which Olympus is pushing the continuous AF
capabilities, it's a disappointing result.
Tracking is a particular disappointment. If you specify an AF point, the
camera will usually 'lock-on' to the correct subject but it gets very easily
distracted. No matter how distinct the subject might appear (being the only
red item in the frame, for instance), the camera will often decide it's
much more interested in the background after a couple of frames. This,
combined with the continuous AF's hunting, means you simply can't rely the
system to get your shots in focus.
Unhelpfully, the camera doesn't indicate that Continuous Autofocus is not
available in high-speed (9 fps) mode, and during shooting, you may never
realize. With continuous tracking AF activated the focus tracking target
will still move around the viewfinder as you capture your high-speed images,
but the clue lies in the hundreds of out-of-focus shots that you'll end up
with - the camera might behave like it's trying to track the subject, but
focus is actually fixed at the first frame of the burst. To get tracking AF
you have to shoot in Continuous L mode. |
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