On Mon, January 5, 2009 10:37, PhotoRoy6@xxxxxxx wrote: > Isn't the difference between older lenses and digital lenses the size > of > the lens? ie the digital lenses can be made smaller (and cheaper) since > they > only have to cover the area of the sensor be it C-APS size or 4/3 format > size? Digital lenses will therefore be limited if one then goes to a full > size > 35mm sensor camera later on? Nikon calls them "DX", Canon "EF-S" -- they cover only the smaller sensor areas. These lenses won't fill the film frame (or full-frame sensor) (at all focal lengths; some of the zooms cover full-frame through part of their range, but not all the way to the wide end). But that's not the only difference. Digital sensors are more sensitive to the angle the light comes from, so designs have tried to give shallower exit angles (quite a challenge for some wide-angles). And the the sensor is shinier, so reflections back from the back lens elements are more of a problem, so better coatings or whatever have been applied to reduce that problem in some lenses. I wouldn't promise this list is complete, either. -- David Dyer-Bennet, dd-b@xxxxxxxx; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info
