I have a Canon EF 70-300mm f/4.0-5.6 IS USM Lens and I would like to a bit more reach.
I am torn between
Sigma 150-600 C
or may be a second hand Canon 100-400 like this as some reviews imply that this could be almost as good
EXCELLENT Canon 100-400mm USM Telephoto Lens eBay
or maybe my existing lens with a teleconverter
This will be used mainly with a Canon 350 D or Canon 550D for birds/mammals any ideas?
The more I read the more confused I get