In Canon lenses, what are Image Stabilizer, Ultra Sonic Motor and Luxury Line for?
Image stabiliser: Does what it says on the tin. Corrects shake using a gyro sensor and motor within the lens. It is most effective at longer focal lengths and / or longer exposures. IT WILL NOT correct motion blur by the subject & IT WILL NOT give you extra light to work with, the laws of physics still apply. USM motor: Faster focusing and quieter than non-USM. Ring type USM (usually L lenses) are exceptionally fast focusing given a decent body to work on. All current EOS cameras have good AF, the higher up the range the better and better it becomes. Luxury line: The L series. Almost always (though there are a few exceptions) weather proof, usually with the use of special optical elements to correct optical flaws. Conceived and constructed for Pro use. Canon make some excellent non L lenses, but the pick of the bunch are here.
