The Smarter Focus ToolSpyderlenscal™ provides a fast, reliable method of measuring the focus performance on your camera and 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 and durable, with integrated level and tri-pod mount..The Problem:Photographers have enjoyed the benefit of autofocus for 25 years now, but many still struggle with its accuracy and repeatability. Auto-focus is a great convenience, especially in fast shooting situations. But typically the first step in reviewing files from a shoot is tossing all the images where the focus isn''t quite right. This can be motion blur or other issues, but one of the most frequent causes is auto-focus error. We tend to blame this on the camera choosing the wrong object, or the wrong point on the object as the focal point, but there is another possibility, one we hate to consider, given the price of the hi-end lenses we use: the auto-focus of our lens may simply be off. When you take a simple shot of a flat object perpendicular to the camera, and it still isn''t quite as sharp as it should be, you have to accept that this may be the cause.