Question / Help Confused about Webcams

[Alex C]

Hi everyone,

I am trying to record video in HD. Just simple video, not streaming, and not trying to broadcast anything I'm doing on my computer. After doing some research and watching what people had to say, I ended up buying a Logitech HD C920 webcam. I figured it would be more versatile (and inexpensive) compared to a point-and-shoot type digital camera with camcorder functionality.

What I don't understand is why I have to mess with all of these encoding settings just to get decent quality? Why can a tiny handheld camera with very little processing power capture HD video and even give it to me as a finished mp4 file, but this HD webcam needs loads of processing power from my computer for encoding? I've followed the guides on the site for getting higher quality video, but it slows my computer down significantly and I end up with chunks of pixelated or frozen video while the encoding catches up (my computer isn't terribly slow either, I have 8 GB ram and a quad core, with dedicated graphics card). I understand why I needed to change the visual settings- brightness, exposure, gain, etc. - that all makes sense. But why can't I just simply plug in my webcam and record a video that looks like the preview does? Why all the extra nonsense? I am just having a hard time wrapping my head around the whole thing.

Any insight/explanations or advice for getting better quality without slowing my computer too much would be very much appreciated.

 

[GiacoAV]

Hello,
It's effectively weird that you have all this problem, but will try to answer to all of your questions.

• Firstly : If your camcorder/camera is better than a webcam in therm of video quality it's normal! tiny cameras means tiny sensor, which add more noise to your vide feed. Also with a webcam you don't have much space to store chips for de-noising, capturing and processing of the video feed, which camcorder and cameras have. Finally, a webcam need to send the video feed to your computer as fast as possible, so this include video quality compression and loss, cameras and camera don't care about that because you save it on a sd card, so they have time to process.
• Secondly : You have to configure your webcam before filming because, as i said : no place for processing chip! Most of camcorders are entirely automatic, exposure, gain, colors and white balance are set automatically with care!
• Lastly : If you have slowing down, it's again normal because your computer has to cache your webcam feed to your hard drive or RAM and send it back, so the solution for minimizing lag will be to slow down the resolution to 1280x720, it should partially resolve the problem!

In hope that I've answered all of your questions! If you have another, don't hesitate to ask!

 

[Alex C]

Thank you for the quick reply. So if I understand you correctly, cameras/camcorders have built-in chips that allow them to process and encode quickly, and then write to an SD card without as much compression. Meanwhile my webcam has to use my computer for all that processing, and it has to compress a lot of data to send it via USB. Is that right?

So basically, my webcam will never record as high quality as a point-and-shoot digital camcorder? If only I had known that a month ago before I bought this. :P

 

[GiacoAV]

You understanded everything! The best webcam ever will be the comming SUB2r, a webcam made for streamers with streamer who transmit uncompressed video feed through usb 3.1 (it's obviously compatible with 3.0) or to buy a camcorder and a capture card

Links :

• SUB2r
• Internal capture card (for desktops PCs)
• External capture card (for both desktops and laptops but with a minimal loss of quality)

In hope that i've again answered to all of your questions!

 

[Alex C]

Yes, thank you. I am disappointed but at least I understand more what's going on and can make my future decisions accordingly! Thanks for the info.

 

[GiacoAV]

No problem! See you next time!

 

[Boildown]

People often have problems with the C920 or any of the logitech web cams. Usually the problem is solved by not using the 1080p mode. Drop it down to 720p or lower. My suspicion is that the UBS bus isn't fast enough to carry all the data at 1080p (and I think the web cam is a USB 2.0 device, so it has to operate at this speed even if plugged into a USB 3.0 port).