Prosumer cameras typically allow the zoom range to be extended via converters. Converters are add-on lens adapters which expand the picture angle or make it more narrow. For instance, fitting a 0.8X wide angle converter on a 35mm lens will result in a 28mm picture angle. A 2.0X telephoto converter on a 100mm lens will give the picture angle of a 200mm lens. Converters often cannot be used across the whole range of a zoom lens and sometimes only at the end of the zoom range because they would introduce vignetting. Also, the internal flash may no longer work properly because the converter will cast a shadow and/or the flash sensor is covered by the converter.
This article is written by Vincent Bockaert,
author of The 123 of digital imaging Interactive Learning Suite
Click here to visit 123di.com