Spyder Lens Cal™ provides a fast, reliable method of measuring the focus performance on your camera & lens combinations. It allows photographers to obtain razor-sharp focusing or check to see that their lenses are working at their peak performance. This device is compact, lightweight & durable, with integrated level & tri-pod mount. The Problem Photographers have enjoyed the benefit of autofocus for 25 years now, but many still struggle with its accuracy & repeatability. The Solution Many newer DSLR cameras now offer a method to correct this issue: they allow you to store auto-focus correction data for several of your most important lenses Features & Benefits Fast, easy solution for your interchangeable lenses & recent DSLR bodies provides razor-sharp auto-focusing, using modern DSLR autofocus micro-adjustment technology Compact, lightweight & durable, with integrated level & tri-pod mount, making this the most convenient way to adjust your own camera gear Save time & hassle of sending your equipment in for service. Now you can check or calibrate your own lenses Accurate & repeatable Calibration of your lenses & recent DSLR bodies Worthwhile investment to ensure your camera is focusing your lenses as precisely as possible