[Tom Bombadur]

Steht zwar ganz oben in meinem ersten Posting, aber hier noch einmal

Canon 75-300 USM IS 4.5/5.6

Bei einem Cropping ergibt sich folgende Brennweite: 120-480mm Brennweite








Technische Details:


Image Stabilization (IS)
As already mentioned, this is the first Canon IS SLR lens, and according to Canon the IS allows you to handhold the lens at shutter speeds that are two stops slower than otherwise possible. In accordance with the classic "1/focal length" formula a camera with a 300 mm lens, for example, must have a shutter speed of at least 1/300 sec, but if you use a 75-300 IS at 300 mm Canon claims that the camera can have a shutter speed of about 1/75 sec. In my opinion it is difficult to say precisely how well the IS works in all situations, but Canon’s claim seems to be fairly realistic. However, IS is no replacement for proper technique, so if you shake the camera the photograph can be blurred even if it was taken with IS, and a photograph that is taken at a slow shutter speed without IS can be fairly sharp if you hold the camera still enough. The IS of the 75-300 neutralizes both vertical and horizontal camera shake, so unlike some more expensive IS lenses it has no special IS mode that allows you to pan with the IS turned on. Also, unlike the IS of some "L" series telephoto lenses it does not work properly if the camera is mounted on a tripod, but it works fine with a monopod, and then the shutter speed can be at least 2-3 times slower than would otherwise be required without IS.


The USM motor
Unfortunately the USM motor is of the "micro ultrasonic motor" type, and unlike USM lenses with "ring ultrasonic motors" it has no "FTM" ("full time manual focusing"), so you have to press a small button on the lens to switch from autofocus to manual focus. This can be a problem on Canon bodies that have trouble with autofocus in low light conditions (e.g. EOS D30), because if the autofocus fails because of low light you can’t switch to manual focus as fast as with lenses with FTM. Fortunately the problem only occurs under fairly poor light conditions, and normally everything works fine. Also, it is of course not all Canon bodies that have problems focusing in low light, and with EOS 1v, EOS 3 etc. the lacking FTM probably won’t be important.

http://www.canon.de/pro/fot/slr/obj/...1_4.0_5.6isusm