Home Forums Gear Photography 2X multiplier

I have a Canon 100-400 IS lens, and I'm thinking on getting a 1.5X, or 2X multiplier for it. Any suggestions on a good one to buy? I tried one out at a local camera store, and found that it didn't function on auto focus. Are they all that way?I had to put it on manual and focus it that way. Thanks.

Get the Canon EOS 1.4x or 2x teleconverter, you should have full functionality in terms of autofocus, exposure and IS. They're expensive, but so was your lens. Putting a cheap teleconverter on a good lens is both a waste of money and a waste of a good lens.

http://www.bhphotovideo.com/c/product/732113-USA/Canon_4409B002_Extender_EF_1_4X_III.html

Not quite that simple, At 400mm that lens is a 5.6 aperture lens. By adding the extender you are effectively changing the aperture to f8 or f11 and unless you're shooting a pro body it will not auto focus.

Yes, I'm very much aware that a teleconverter will slow my lens down. And clarity over long distances will be affected too, but anytime you shoot through lots of air, that's going to happen, with any lens. I can counter the slower lens speed with increasing my ISO, so not worried about that. Increasing ISO doesn't do much to the grain like it used to with film.
I'm shooting a 40D now, and will be getting a 70D, once they are released. The word has it that the 70D will be released later in April.
But it does make sense to get a good converter to go with a good lens. I'm not going to go with a cheaper after market converter to put on my 100/400 IS len. You get what you pay for, as they say.
Thanks for your info.

I am interested to see your results.

I have used Canon multipliers with L series glass for a few years. From a 300 F 2.8, 70-200 F 2.8 IS, or my favorite a 135 F 2.


Buy the Canon and don't look back. I prefer the multiplier with fixed lenses for several reasons. Image quality degrades with the multiplier, a faster lens helps offset the loss.

You can't be using a 100-400 indoors to any successful degree, really nor should you, so the multiplier may be of some advantage to you in bright light.

ISO is not a fix all for having a 'slower' lens, sure it may help in a pinch, but it is a crutch that does not address the real problem.


Hope this helps