This is a small library for controlling webcam properties such as focus, zoom and exposure. It's intended for use with the Logitech C920, but it will work with other USB cameras too.
Also included is a Windows application for controlling the camera properties. This is similar to the advanced settings page of the Logitech camera control utility but supports storing presets and customising which settings get displayed.
This project was built using Visual Studio 2015 Community, and depends on Directshow.net.