Can only have 2 cameras?? I can't have 3 why?

[gmrsradio]

Hi

I want to add another camera, but when I try, I get a black screen. I can run 2 cameras without a problem. So is OBS limited to 2 cameras?

Thanks

 

[Harold]

Some models of camera do not allow multiple of the same model to be in use at the same time.
USB hubs break cameras.

 

[gmrsradio]

I should have said I am not trying to run the same model of camera. I am using a power USB hub. I have been playing around with it and looks like just 2 I can run for whatever reason.

 

[Harold]

USB hubs, powered or not, do not work with cameras.

 

[gmrsradio]

hummm i think my other 2 are plug into the hub humm i think. I will have to check now. lol so basically if a computer doesn't have enough USB ports then what does a person do?

 

[Harold]

If it's a laptop, there's nothing you can do
If it's a desktop, you can buy USB controller cards.

 

[gmrsradio]

ok thanks

 

[Lawrence_SoCal]

For those looking for some technical details
- Issue is USB Root Hub bottlenecks. Depending on computer (and no, this is almost never published/advertised) you can have different quantity and quality USB Root Hub (some controlled by CPU, and then others... the others being sometimes good, sometimes not)
- external USB hubs - often low-quality chips inside... which then is a problem

For a laptop, if you have a Thunderbolt port (or new USB4) and Thunderbolt dock (quality, again, not necessarily lowest cost item), or a high quality USB4 hub, then you might get something that works. But for a laptop, that hub/dock still goes into a single port, and depending on quality of motherboard components... may or may not work.. sorry, wish there was a clear/easy answer, but not in this case.

 

[gmrsradio]

Ok thanks for the tech info, that is good to know!

 

[gmrsradio]

After messing around for a while, I got 3 cameras to work, so I want to post how I am doing this to help others out:
My old laptop has 3 USB port, so I took the webcam and the document camera and plug them into the laptop. The other USB port that is on the laptop I plug into a power USB hub. Now my 3 camera is a digital microscope which has outputs for USB or HDMI. So I bought an HDMI to USB capture card and I plug this into the USB power hub. So far this seems to work, however I have not run this setup for a long period of time. Once I do, I will post here to let ya know.

i hope this helps people and maybe it will give them some ideas on how to get 3 cameras to work.