Hi all, I`m looking for some advice. I have an F70 which I have been using for nearly a year to photograph retrievers at work in the field. Because they are often 30-50 metres away, I neeeded more than a 200 mm, so I recently invested in a Tokina f4.5 100-400 zoom. I like the lens, and it is fairly easy to handle as zooms of that length go, but some of my shots are blurred, and I don`t know whether it is through subject motion or camera shake. I`m wondering if anybody could suggest a shutter speed or shutter speed/aperture combo that might work. These dogs are usually on the run, and some of them get going quite fast. Lighting conditions are rarely a problem, since the shooting is done outdoors. The guy at the camera store advised me to shoot at a shutter speed of one over the focal length of the lens, in this case one four-hundredth of a second. Will this suffice, or should I go higher? Any advice would be appreciated, since people sometimes buy these photos from me, and I can`t afford to mess them up through blurring. Thanks, Paula
