Focus

All camcorders have auto focus system to ensure that the subjects that we are shooting are sharply focused. The systems use infra-red beams fired from beside the camcorder's lens to measure the camcorder's distance from the subjects. Some others camcorders use the method through the lens(TTL) where the image sensor detect the image sharpness.


AUTO FOCUS

The systems can interprete what the lens sees and keep the shot always in focus. An auto focus works firing infra-red beams to the subjects. The infra-red reflected back to the image sensor in the lens. The camcorder measure the time take by the infra-red beams to return back to the sensor. With the times, the system will calculate the distance. Then the focussing ring of the camcorder will adjusted by an electric motor.

However in certain situation, auto focus setting cannot be used, because the subject that we are shooting becomes inaccurate. In other words the subjects are not accurately focussed. To overcome this problem, we should use manual focussing.


The situation where auto focussing is not effective:

• Shooting subjects through the bars or netting. Auto focus will focus the bars in the foreground not the subjects.

• Subjects are under low light situation. The infra-red systems have difficulty to measure the distance of the subjects.

• Subjects that are move very fast. The subjects will cause a temporary lost of focus.

• Subjects that are placed at the edge of the frame.