SQF results were Excellent at all three tested focal lengths -- a big improvement over the pretty good non-IS version. Good distortion control, too, with Slight barrel distortion (0.18%) seen at 70mm, Slight pincushion (0.20%) at both 135mm and at 200mm (0.29%). Light falloff was gone by f/4.5 at 70mm, by f/6.3 at 135mm, and by f/5.6 at 200mm. This is no macro lens, although at 200mm it achieves a respectable 1:4.35 magnification (45.5 inches). At 135mm, it gets to 1:6.33; at 70mm, 1:11.4. With IS at 200mm: All testers could gain up to 3.5 stops. Lowest gain: 1.5 stops. Highest gain: 3.5 stops.