A method for reducing an effect of a video artifact includes adjusting a phase of a second imaging device's video clock signal so that a phase of the second imaging device's video synchronization signal matches a phase of a first imaging device's video synchronization signal. An endoscopic system includes a first imaging device, a second imaging device, a light source, and a controller that reduces an artifact in an image produced by the first imaging device. In some embodiments, the first imaging device faces the light source.