I was shocked to find no simple way to change basic webcam settings (gain, exposure, etc.) from the command line on Windows. After much time spent looking at existing approaches, I finally gave in and wrote this little program.
An earlier C# version of this program is CamParamSharp.
// List available devices.
CamParam.exe
// Output
0 HD Pro Webcam C920
1 OBS Virtual Camera
// List properties for a device.
CamParam.exe device 0
// Output
Pan 0
Tilt 0
Roll 0
Zoom 100
Exposure -5
Iris -5
Focus 15
Brightness 128
Contrast 128
Hue 128
Saturation 128
Sharpness 128
Gamma 128
ColorEnable 128
WhiteBalance 4200
BacklightCompensation 0
Gain 64
// Set exposure and gain for device "0".
CamParam.exe device 0 gain 64 exposure -5
// Output
Exposure -5
Gain 64
The basis of this program is heavily influenced by CommandCam.