Prior to the most recent Teams update, my webcam properly adjusted the brightness during Team's video calls. Following the update everything appears dark on video conferences and adjusting the settings appears to have no impact on the issue.
Microsoft Teams Version 1.1.00.10955 (64-bit)
Microsoft LifeCam Cinema Driver Version: 10.0.16299.15
I'm having the exact same issue. I can be in a meeting in Teams and toggle between my Lifecam Cinema and the OEM camera in my laptop and they are night and day (pun intended). The Lifecam is extremely dark.
Hi Ron. So my IT department actually came and installed a new video card in my PC. That appeared to fix the issue, but after a couple of weeks the same exact thing happened. Camera appeared very dark in Team's meetings and elsewhere. It actually ended up being the Microsoft camera itself. They recently ordered me a new one. After we replaced the video card and the issue occurred again, we realized that it was actually the physical camera. Not sure if yours is still under warranty, but since your laptop camera is working it sounds like you may be experiencing the same problem. Best of luck!