Focal length dictates the depth of field that a lens can achieve. For example, a 300mm standard lens on a 10x8in camera has the same depth of field as a 300mmm telephoto lens on a 35mm camera. Digicam lenses have a minimum aperture of around f8/11 due the small circular field of illumination necessary to cover a typically small sensor. Any smaller and all manner of lens abberations begin to creep in.
Hope this helps William Curwen =============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE
