Quote Originally Posted by sedwards View Post
Here is another question then. If i have a crop sensor and shooting 300 mm is 1/320 shutter speed my minimum or hould i multiply by 1.6 ? I will post some of my pics tonight when i get home .its mostly when things are far and im at 250+ mm that i find it is not sharp at all. Even in bright sunlight ive tried from f6.3 to f11 and cant see much of an improvement. Im hoping thats the best this lens can do and an L series will give me more sharpness , or maybe ill get lucky and find out im just doing it wrong lol
The rule of thumb without IS is 1.6x the focal length for a minimum shutter speed on a crop body. It's just a rule of thumb though. Some people have surgeons hands and still subjects and can pull off slower shutters. But the shakier your hands, and the more your subject is moving, the more speed you need. This really starts to come more naturally with lots of experience.

Also, subjects that are moving laterally require a much faster shutter to stop motion, whereas subjects moving towards you dont require quite so fast a shutter.

It will be very helpful to see some of your images and the corresponding exif data. People should be able to help you a lot with those two things.