Check the camera’s own live USB mode
Check your camera’s manual for a USB webcam (UVC) mode and any software it needs on the computer. Camera makers publish their own webcam apps, for example Sony's Imaging Edge Webcam and Canon's EOS Webcam Utility Pro; check that your model is on the app's list. A USB socket used for files or charging doesn’t mean the camera can stream over it. Select the documented mode and check the actual available resolution in your application.
If live USB is supported, try that path before adding capture hardware. Confirm the audio source separately so a camera microphone does not duplicate your main microphone.
Still choosing? Best camera for streaming sorts the cameras we cover by whether they have a USB webcam mode, a long zoom or a larger sensor.
Use clean HDMI when USB is not the path
For an HDMI capture path, check that the camera sends live video and that its overlays can be removed. Match the camera’s mini, micro or full-size HDMI connector to the capture input. Check the camera’s continuous-operation and external-power conditions.
Add the capture device as an OBS Video Capture Device source and choose a supported mode. The camera capture checker records the prerequisites you still need to settle.
Check a full session
Record with the camera, power and app arrangement you will use. Include focus changes, movement and the duration you need. If it stops, use the camera shutdown checks. A brief clean preview does not prove that the feed stays up. Using a phone instead? See use your phone as a webcam.