Canon Tele Extender

[frank]

I seen some talk on Tele extenders but I got the impression that the canon 1x4 tele extender will only work with L Lenses, am I wrong or would it also work for example with a Sigma Zoom 70-300mm f/4-5.6 APO DG Macro. If so how much degradaiton is there.

 

[grumpybadger]

The Canon extenders will only work with certain Canon extenders. Those that have them speak highly of the Kenko teleconverters which will work on other lenses.

Teleconverters will degrade the image (or magnify the weaknesses in the host lens) so cause some degredation with all lenses, zooms are more susceptible.

You also lose a stop of light on a 1.4x and 2 stops on a 2x. So, with your Sigma you will lose autofocus with all but the top Canon pro bodies (1 series)

 

[frank]

Thanks grumpybadger, think I'll forget them for now then.