Using a "proper" camera as a webcam

Since I'm still mostly using my old Macbook (late 2014) and a Sony A7II + (Sony FE 55mm f/1.8), I soon realized that with a basic USB capture device (a UVC device that exposes an uncompressed video as webcam) I couldn't get anywhere past 360p with 24fps, and even then, CPU was skyrocketing.

Next I tried to utilize an Raspberry Pi that I have to stream the video, but using VLC as well as FFMpeg and few other streaming products, all did not do well when it came to resolution, fps and latency.

At the same time, I researched some existing USB capture devices, and while Elgato seems like the popular choice, non of their USB capture devices perform hardware h.264 encoding, so the bottleneck remains the host machine.

The only two hardware brands that I found at the time (around a year ago) that made USB capture devices with on-board h.264 encoders were Blackmagic and Magewell.

I went with the Magewell USB Capture Gen 2 which seemed to do exactly what I wanted and no more than that. I was able to find for ~$80 and it has worked perfectly since — no latency or missing frames at 1080p. It also has a very nice management console that let you tweak the (hardware) encoding (enable/disable mirror mode, crop frame and more).

EDIT: another thing that I tried was to use Sony Imaging Edge Webcam — a USB driver that turn Sony cameras into UVC (webcam) device. It works pretty well but has a max resolution of 1024 x 576. Not what I was looking for but still I remember it as being equal or even better than combining a cheap HDMI to USB devices that don't do hardware encoding with OBS for virtual camera.

I'm am at a loss as to why this guy is comparing said camera to cameras in the region of £600-1300. if they could produce 20x the quality, then it might be a wothwhile comparison, but they evidently cannot

the C920 has inbuilt hardware h264 encoding (for £30!) which the majority of video streaming and conference platforms will thank you for, freeing up your processor to focus on network quality - which is far more important than choice of camera

the C920 also outputs its nicely pre-encoded stream at 1920p, so I'm not sure why this guy is testing at 720p. perhaps he doesn't realise this and is why he is surprised by the wider angle. perhaps his £600-1300 "proper" camera or HDMI-to-USB only outputs at 720p. who knows. maybe if he'd have spent less time faffing around with desmurfification and Moire he'd have noticed this in the settings

I was expecting an article comparing the C920 to an affordable proper camera with some ffmpeg wizardry, but all I got was a wishy-washy amateur photographer with a stable internet connection and lots of money to burn

In any case I find if you sit close to your camera, 35mm is a good FOV that will fit in your head and shoulders. The background blur for f/1.8 works well if you enable Servo Autofocus with Face Detect. It will momentarily get confused if you step out of the frame and back in again, but it can track a face pretty well after that.