1.4 Tele Converter

[Stubbs]

I understand there are some Canon lenses that can not use a teleconverter. I have a Canon 75/300 IS and would like to use a 1.4 or 1.7 converter as these can be used with AF I am told. I presently have a Kenco 2X which is not the greatest when used with this lens and it will not AF. Can I use a 1.4 or 1.7?

[OviV]

The canon 1.4x and 2x will not work with that lens. They primarily work with L lenses although I believe not with all of them. The 1.4 will cost you one stop and the 2x will cost you two stops. That means that if you have a lens capable of a max apperture of 2.8, you will only get 4.0 with the 1.4x and 5.6 with the 2x. Unless you have a series one camera that can focus up to f8 you will lose auto focus at anything above 6.3.

Ovi

[CyberDyneSystems]

Hi Stubbs,. welcome to the forum :)

For additional info on this subject.. please take a look at the -=EOS STICKY=- at the top of the frum. there is a wealth of info re: T-cons :)