Canon Extender EF 2x III Converter

[Alan46]

Hi people,
I was considering buying a Canon 2X converter to use with my EF100-400 F4.5-5.6 IS USM.
I plan on using it for motorcycle racing and hopefully good sunny weather.
I reilise that I could be losing auto focus if conditions are not as bright as I hope.
Just wondering if anybody has had any dealing with the converter and wishes to share experience.
Or what I'm really asking is should I buy one...
Thanks again in advance.

[JonnyM]

I've used this combination once at the MotoGP in Catalunya last year so not a great deal of experience. I did need to increase the iso to 800 a few times to keep the shutter speed/aperture combination, so bright conditions are ideal (cloudy and raining in Spain!). I was using it with a Canon 60d so had even more telephoto capabilities. As you probably know teleconvertors work better with prime lenses and you may well do better with the Canon 1.4x. I also used the 2x convertor with the Canon 300mm L f2.8 which worked well together.

I'll post a few images of the racing to illustrate later on.

Jonny.

[Alan46]

Thanks Jonny, much appreciated.