JVC GY-HM650和未来相机的形状
JVC's GY-HM650 is a new three-chip CMOS camcorder with computer-like functionality that enables Inter网 connectivity and a second encoder that enables shooting and storing two different formats to SD card, or storing one format and transmitting live streaming video. Part 1 of this 2-part review details the mechanics of the online and dual-codec capabilities. In the second, we'll look at the GY-HM650 as a traditional camera and test quality and usability.
The key hardware differentiator between the JVC GY-HM650 (下面的图1) and virtually all other ENG cameras comes down to a simple full-sized USB port, plus the hardware and software necessary to leverage its functionality. 具体来说，USB接口等., allow the camera to communicate wirelessly, whether via a wireless 网work or via 4G LTE. That lets the camera stream live while storing the video at full resolution to an SD card, 或FTP现有的文件，同时拍摄. It also allows you to control the camera from any computer, 调整重点, 变焦, 还有其他参数.
图1. JVC GY-HM650, USB接口有4G调制解调器.
To implement the live streaming functionality, JVC had to add a second encoder to the camera. 当你不直播的时候, you can use this second codec to encode and store SD or web video to the second SD card, 虽然第二流编码选项是有限的. 尽管如此, the second codec and online aspects of JVC’s new camera makes the GY-HM650 alluring to any shooter tasked with shooting on location, 或者用于流媒体, or otherwise has to quickly transfer video files from point A to point B. 在某些情况下, this new functionality eliminates the need for an on-camera encoder/4G transmitter, 价格从500美元到5美元不等,000或更高.
这是两部分回顾的第一部分. 在第一部分中, I’ll describe seeds and feeds and detail the mechanics of the online and dual codec capabilities. In the second, I’ll look at the GY-HM650 as a traditional camera and test quality and usability.
速度和进给
The GY-HM650 is a 12"x8"x5" camcorder that weighs about 5.3磅，包括电池. It’s a three-chip camera with three 1/3-inch 1920x1080 CMOS imagers. The fixed lens is a Fujinon 23x 变焦 lens, with a 35mm conversion of 29mm-667mm.
摄像机可以同时编码为MPEG-2和H格式.使用MOV, MP4, MXF和AVCHD包装的264格式. Inconveniently for those who have to write about the camera, the specs for each codec/wrapper combination are all different. 以下是一些亮点. For those shooting AVCHD-formatted video, you have four modes: HQ (1920x1080 @ 24 mbps at 59.94/50i)， SP (1920x1080 @ 17 mbps在59.94/50i)， LP (1440x1080 @ 9 Mbps在59.94/50i)和EP (1440x1080 @ 5mbps, 59.94/50i). 记录H时.264 into a QuickTime wrapper, you can record into 1920x1080/59.95i (50i PAL)或23.98p.
值得注意的是，这里没有H.264 mode compatible with 720p recording, so if you want 720p, 你必须用MPEG-2存储 format. 因为以60fps录制只能在720p模式下使用, 如果你想拍慢镜头, 你必须用MPEG-2存储. That’s not terrible; I still shoot quite frequently in HDV, 哪个是MPEG-2, but almost always shoot at 720p in AVCHD mode when available.
SD模式只有H.264在QuickTime包装，存储在720x480/59.94i (720x576/50i PAL) at 8 mbps in either 4:3 and 16:9 aspect ratio. Web modes are limited to 960x540 at 5 Mbps, or 480x270 at 1.2 Mbps，都是29.97p, 23.98便士，或者25便士.
相关文章
In performance testing, the JVC GY-HM650 produced exceptionally sharp quality. It offers very good manual controls and outstanding auto-mode performance, and shoots very well-balanced pictures in a range of lighting conditions.
爱国者联盟, a Division 1 conference with sponsored championship competition in 24 sports, has purchased 30 JVC GY-HM600 ProHD cameras as part of 10 portable video production systems to stream live coverage of sporting events from its member schools to its digital 网work, 与Campus Insiders合作
JVC's new GY-HM600U ProHD camera incorporates very high-quality components, 有一系列有用的特性, 在我的测试中拍摄到了非常清晰的视频. If you're in the market for a sub $5,000 camcorder, the HM600U should be on your shortlist.
Shawn Lam和Dave Walton讨论JVC GY-HM650 2.0, JVC's newly updated dual-card/dual-codec ProHD camcorder with built-in FTP and live-output capability and a 23:1 Fujinon lens.