Webcams are typically optimized for indoor use, and can appear washed out when pointed outside. There are brightness and contrast settings that may be accessible from the software that came with your webcam, or through third-party applications. You may need to adjust the exposure, which is not always available (though there may be third party software that works with your webcam; people have also been known to put a pair of sunglasses in front of the webcam lens! Keep in mind, however, that cutting back exposure will make your images look darker when the sun goes down. In fact, if you need to record video over a long period of time during the day, a network camera would probably work much better. Recognition accuracy will decline when contrast is not good.