Teleconverters ?

[Mitcon]

Hi all,

New member here & also new to photography in general. Just got a 350d the other week & I'm enjoying it already. I'm shooting birds mostly atm, I have the kit lens & a 75-300II usm. Thinking of getting a Bigma shortly.

Question I have is about teleconverters. I know that I will lose a couple of stops of light & AF with these lens. I'm thinking of getting one but wanted to know the difference between the 4 & 7 element ones & which is better ?

Cheers
Mitcon

[Wildman]

Look at the stickies on TCs on this site. In general, a 1.4 TC will lose you one stop and a 2.0 TC will lose two. Depending on your camera and lens, this might make auto-focus marginal, or even impossible... Also, compatibility of lenses with TCs is discussed. Take a look at it and avoid buying the wrong thing.

eg. with a 1.4 TC, an F/4 lens will act like an f/5.6 which is the smallest a DReble or 20D can reliably autofocus. A 2.0 TC will act like an f/8 lens and will fail to autofocus. The number of elements in the TC doesn't seem to have much effect as far as I've read.

[condyk]

Wildman is right ... check out the sticky!

I used the Kenko Pro 300 1.4 on a Bigma and it worked well ... you need lots of light and lose mAF but you know that. The Kenko Pro's are great value and more flexible that the Sigma and Canon versions as they can be used with more lenses. Popular choice on this forum. Scores something like 4.68/5 on user review site, similar to the Canon and Sigma's.