It may seem like my long, winding exploration of webcams has stalled, but I assure you that’s not the case. I’m moving as fast as the industry will permit. The fact is that the industry just isn’t moving very quickly.
Back in October 2013 I first penned something about my hunt for a USB 3.0 webcam. At that point there were basically none to be had. A few months later when Vaddio presented their Huddlestation product on VUC472 they mentioned that USB 3.0 capable chip sets for such devices were anticipates later in 2014.
Well, it’s now well into 2016 and where are the USB 3.0 webcams? I actually get asked this question quite a bit, most recently in a tweet from George Ou of ZDNet.
— George Ou (@GeorgeOu) March 10, 2016
While I responded to Mr. Ou, the question comes up often enough that I’d best address it here in the open.
There are some USB 3.0 webcams available. These tend to take the form of PTZ cameras for use in video conferencing situations. Minrray is a leading manufacturer of such cameras. Their North American presence (Minrray.com) is fronted by Conference Room Systems, an AV reseller in Pennsylvania. CRS offers a line of cameras branded as PTZ Optics.
True to their word, Vaddio now offers some USB 3.0 connected cameras. Their ClearShot 10 (pictured, $1700 ) is a fine example. A remote controlled PTZ camera with a 10X zoom range, it has both USB 3.0 and Ethernet connectivity. Its sibling, the RoboShot 12 ($3400) adds Gigabit Ethernet with POE+ support and HDMI video output.
What Does USB 3.0 Get You?
Both these cameras give us some insight into what’s possible when leveraging the increased bandwidth of a USB 3.0 connection to the host computer. The Ethernet connection delivers an H.264 encoded 1080p30 stream via RTSP. The USB 3.0 connection supports uncompressed 1080p60. Both connections are active simultaneously, which makes it possible to centrally monitor the compressed feeds while also making an uncompressed local recording to a computer.
Basically the USB 3.0 connection allows software that’s not written to leverage on-camera compression (UVC 1.1 allows MJPEG, UVC 1.5 allows H264) to achieve 1080p60 operation.
That was not what George Ou was seeking when he posed his question via twitter. He was seeking a webcam that could deliver a 4K uncompressed stream. More specifically, he sought a camera capable of 4K (3840 x 2160) in 4:4:4 color space. His aim being to down-sample that to a more optimal 1920 x 1080p at 10 bit color depth. Shutter Angle has a nice article on why you might wish to do this.
Sampling – 4:4:4 vs 4:x:x
Mr. Ou’s desire for 4:4:4 color sampling is notable. All the webcams I have used (many more than a normal person) sample the video frames in some kind of 4:2:2 or 4:2:0 manner. Most “video” is conveyed at 4:2:2, or even 4:2:0 sampling, where the amount of resolution in the color planes is dramatically less than the luminance portion of the image. This has long been done to conserve bandwidth and storage. It’s based on the understanding that the eye is much more sensitive to the brightness of the image than its color. A high-resolution black and white image can be overlaid by color at reduced-resolution and the eye thinks the image looks fine.
There are times when full-resolution in the color channels is helpful or even necessary. The most common being when recording green screen scenes to be composited in post-production. Recording in 4:4:4 is used to ensure that the compositing process is a clean and seamless as possible.
In reality, the matter of color channel sampling breaks down into two paths, driven by application:
- The superior imaging provided by 4:4:4 sampling (even 8:8:8 on rare occasion) is used for production applications, where sustaining the image quality is paramount.
- Lesser sampling schemes are deployed in distribution of the finished work, like encoding for DVD, Blu-Ray or streaming.
Mr. Ou’s goals were lofty, hardly what you’d consider “a webcam.” They had a lot more in common with the BlackMagic Design Production Cameras, although none of those cameras provide USB 3.0 connectivity. A high-end camera feeding a 4K capture card or USB 3.0 capture device is mostly like to meet his requirements.
The simple fact of the matter is that at this very moment in time there still aren’t any 4K webcams commercially offered.
Ok, there may be one…sorta…from Altia Systems. This company, just a few years old, makes a USB-connected camera designed for video conference applications. It delivers a 3840 x 1080 pixel panoramic video stream . The camera actually stitches together the streams from a trio of 1920 x 1080 sensors to create the panoramic stream. It’s not a single 4K sensor.
In truth, the Panacast 2 camera ($995) is novel. The extra large image size allows it to synthesize a kind of PTZ (they call it ePTZ) functionality without the cost of complexity of PTZ hardware. The client application thinks it’s dealing with a normal UVC camera, but the “shot” can change in respond to UVC PTZ commands. It works with any client app that would use a webcam.
The Panacast 2 camera has a USB 2.0 connection. It’s ability to deliver MJPEG compressed frames enables 3840 x 1080 pixel, 4:2:2 sampled, 8 bit frames at 30 frame/sec in around 100 mbps. That assumes 20:1 compression as I’ve described previously.
The Panacast 2 camera is reminiscent of the Polycom CX5000/5100/5500/8000, except that it’s not tied to Microsoft Skype-For-Business. Also, with a field of view of 180 x 54 degrees it’s panoramic, but doesn’t deliver a full 360 degree field of view.
I gather that Conference Room Systems will be announcing their next generation of cameras next week. There will surely be some USB 3.0 connected models offered. Although I doubt very much that they will offer 4K resolution. It’s more likely that they move into on-camera H.265/HEVC compression to reduce the bandwidth requirements for all the existing video formats.