Hacker News Reader

Comment by dekhn | Hacker News Reader

I have an alternative approach that I discovered recently while building a microscope with a webcam driven by linux.

Nearly all modern cheap webcams are UVC-compatible and they work with linux. Different models expose different functionalities, but I ended up with this: https://www.amazon.com/dp/B07R489K8L

It does 1600x1200 25FPS YUYV (as well as a wide range of other resolutions and FPS) uses the C/CS-mount lens standard (easy to buy a wide range of high quality lenses). It doesn't have a microphone but you should be using an independent mike anyway. Has software control of exposure color temp, and gain, which is great for various lighting conditions.

You read the data through USB, not HDMI. The one thing I haven't managed to do is autofocus, but imho, for webcams you want to set a fixed focus around your head anyway.

Works with all video conference programs, and OBS studio (I actually import the video in OBS and then create a virtual camera).

View on HN

I looked at similar cameras a while ago (Mokose brand), but never got around to it because I was unsure of the lens. Especially field of view (is it wide enough angle?), but also overall quality. I saw a sample somewhere with a dark ring along the edges of the final image.

Did you have any issues with that? Do you have a rough approximation of what zoom setting you're using and what FOV it gives?

I'd love to get a better camera than the built-in laptop one, but also don't want to shell out $1500 plus the hassle of a DSLR…

I use a Mokose 4k USB webcam with a 5-50mm zoom lens that cost under $100 for the set.

I experimented with a huge variety of mounting options before settling on a SmallRig adjustable arm clamped to the top of my monitor mount, so it peeks over the top of my monitor, basically where a built-in webcam would be.

To me it’s the best compromise between control, quality, and price. Having physical control of zoom, focus, and exposure is amazing. Meetings start up instantly, no software to mess with.

To be fair I spent another $150ish trying various mounting options, but those are shared between the camera, mic (Rode NT-USB), and lighting. Eventually I gave up on the camera light and fixed my room lighting. A more frugal person could get a similar setup for $250 all in.

I didn't have good luck with the included lens for web camming. It's a zoom lens with focus and aperture, which is silly for most video conferencing.

Alternative C- and CS-mount lenses are easy to buy https://www.amazon.com/Neewer-Aperture-Compatible-Mirrorless... and will focus near your face and have plenty of light. People will say your background blur is amazing.

Will that lens connect directly to a c-mount frame? You don’t need an adapter that will reduce the field of view so your face fills the entire thing?

> I have an alternative approach that I discovered recently while building a microscope with a webcam driven by linux.

Do you have a web page somewhere describing your linux webcam microscope?

Not really. It's unclear if the time invested in documenting the design is worth it yet. I haven't decided if it would be useful. For now, I recommend looking at OpenFlexure or Flexiscope (there's one other one that's good but I forget the name).

The idea is fairly simple. It's a basic construction kit for simple microscopes (just LED, lens, objective, tube, and camera, all mounted to an aluminum extrusion post using 3D printed parts). Then some inexpensive XYZ stages to move the sample holder holder around for large FOV and focus stacking.

Everything else is just cobbled-together from python, but see MicroManager for a tool that can drive an open source microscope.

I have a very similar hardware setup and love it. What benefits does OBS provide for your video conferencing? If it’s worth the extra hassle I might need to look into adding it.

I use it for the chroma keying in VC software that doesn't support it, like Meet (which has a machine learning system that tries to identify the background). I often present other windows and using OBS is often more ergonomic than connecting and presenting a second window; I can composite a transparent version of my head over what i'm presenting. Or present my whole screen, etc. Basically, twitch streaming for video games and other stuff changed how I do VC.

How do you do present window sharing to a Meet call?

Using OBS gives you a very flexible way to stack a window capture with video sources, composite them, etc, yes, but your output is then routed through the virtual camera driver and sent to Meet as a regular webcam feed.

So because Meet thinks it's just a webcam feed, your coworkers will just see your shared window as a tiny video tile downsampled on the sending end down to 720p, and the only way they have of seeing it large is to pin your video tile manually.

Is there a trick here where you got OBS to output the composite feed to a chromeless window then you share that as a regular application window presentation?

This looks like it should compare favorably to the "real" camera + HDMI capture card solution. The lens is always the most important part of any camera setup, so if you get the right lens, you're probably gold.

Ehh. After a certain point that's true, but a lens doesn't help much with a garbage sensor, particularly one that has to be compensated for with huge exposure changes. (This is the core of why webcams are disappointing, not the lens.)

I use a GH4 or G9 with a USB3HDCAP at my desk because I already have them and the glass, personally, and I know the sensor is not going to be a trailing problem behind the (cheap!) glass that I use.

The sensor is an IMX179 which is a mainstay. I believe the sensor area is smaller, and probably higher noise than a DSLR or mirrorless, but for VC use, it's probably not going to make a difference.

Yeah, I looked--I am not a fan of most of the IMX series, but if it works for you, (unironically) great!

In my case, the "lens" is a microscope objective and a long tube, but I've also tested it as a webcam.

Arducam has a bunch of C-mount lenses, https://www.amazon.com/stores/page/35052708-55DC-4832-A0B6-A... as well as nice USB webcams that let you choose from several sensors. https://www.arducam.com/sony/imx477/

Do you have a sample image from that camera? I bought a similar board, same sensor, with the intent of attaching a nicer lens to it, but quality is dogshit. Absolutely horrendous, like a Nokia phone from 2001.

Reply on news.ycombinator.com