I agree with HDNitehawk that terms like "super telephoto" and " ultra wide-angle" are more marketing terms than scientific classifications.

However, most UWA definitions kicking around out there agree that these are lenses wider than 24mm in the 35mm format, or rectalinear lenses (i.e. not fish eye) with a diagonal angle of view of 90-degrees or wider. This is consistent with the definition I offered above.


Why 90-degrees? One source I've read says that 90-degrees is used as the magic breaking point because it is twice the angle of view of a "normal" or "standard" lens.