Your camera’s Shutter Priority (Tv) mode gives you control over whether a subject motion is sharp or blurred. When using telephoto lenses the old school rule is to use shutter speeds that are the equivalent of the reciprocal of the lens’s focal length is one place to start. When using a 300mm lens, 1/250th of a second makes a good starting point but I typically use 1/500th of a second to ensure sharpness.
Unlike Program mode (the “P” does not stand for professional) you should make sure that the available aperture range is sufficient to provide a correct exposure at the selected shutter speed. If the aperture value flashes in the viewfinder and LCD panel, it means the selected shutter speed is too fast or too slow for an adequate exposure. Select a different shutter speed until the aperture number stops flashing.
Tip: If shutter speed isn’t matched to the speed of the subject’s, some blur will be seen in the image. The direction of motion is also important. If the movement of a person is walking at an average pace at a distance of a little over 16 feet from the camera is to be frozen, use the following shutter speeds as reference points:
- 1/500 sec for movement perpendicular to the optical axis
- 1/250 sec for movement on a diagonal
- 1/125 sec for movement parallel to the optical axis
If the object is moving faster, the exposure times have to be correspondingly shorter. If you want blurred movement, longer exposure times are required.