Canon 70D (stand-alone) video test
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Nowadays, full HD camera is not only high-end DV Only has the function of using SLR camera Video has gradually become popular. Canon EOS 70D It can bring players 1080p full HD video shooting, and cooperate with its full pixel dual core CMOS AF technology and touch screen The application of can make players' shooting more accurate. Next, let's take a look at this camera The effect of live shooting.
1080p full HD video capture（ Original download ）
1080p full HD video capture（ Original download ）
1080p full HD video capture（ Original download ）
1080p full HD video capture（ Original download ）
1080p full HD video capture（ Original download ）
From the perspective of video shooting effect, Canon EOS 70D It is still quite good. Both the focusing speed and the image quality have met the author's previous expectations. Such image resolution is enough to meet the needs of ordinary family users. Interested friends can click on the original film download To watch the original video.
Canon 70D (stand-alone) video test
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Due to the use of DIGIC5+image processor, the ability of EOS 70D to shoot video has been greatly improved. The EOS 70D supports 1080P full HD video recording at 91Mbps bit rate. In fact, we have opened the concept of "full HD", which is too virtual to be true. There may be some parameters you have never heard of, but these parameters are the key to determining the image quality and performance. Generally speaking, 99% of cameras adopt the 8bit 4:2:0 sampling mode, but the compression mode and code stream are different from them.
The video function of 70D is also outstanding among current SLR cameras
The first element is the compression method. The EOS 70D in my hand supports intra frame compression. What's the difference between intra compression and inter compression? In fact, the author would like to put two technical drawings, but they are not as straightforward as the following group of pictures.
Interframe compression
We all know that a video is composed of continuous pictures. If the parameter is 1080/30p, it means that the video contains 30 still pictures per second. Each still picture is called a frame. Intra frame compression means that the machine only considers the data in this frame, and does not consider the redundant data between frames. In plain terms, it is similar to the compression method when we take a still picture.
Inter frame compression, that is, most of the compression methods used by the SLR actually only compress the data that changes on the screen between two frames. One advantage is that the video volume can be effectively reduced. The disadvantage is that the data of the two frames before and after the compression is associated, so the image quality will be lost when editing a single frame picture in the later stage.
Small changes are hard to catch. Have you found them
Canon EOS 70D's code stream is up to 90Mbps when intra frame compression (ALL-I) is selected. Since speaking of the code stream, the higher the code stream, the smaller the compression, the better the picture quality, the more information to be retained, and the larger the later space, but it will greatly increase the video volume, so Canon EOS 70D adopts dynamic coding.
Schematic diagram of VBR coding principle
What is dynamic coding? The machine will adjust the bitstream within a certain range according to the complexity of the video picture. The schematic diagram above is very illustrative. When the picture is not complex, it is encoded with a lower bit stream. In the case of complex pictures, many people, or people doing a lot of movement, a relatively high bit stream coding is adopted, which is VBR dynamic coding. The peak bit stream of EOS 70D is 90Mbps.
Canon 70D (stand-alone) video test
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