Canon UK - EF 100-400mm f/4.5-5.6L IS USM

Hi,
I'm thinking of upgrading my old Canon EF 75-300 to the Canon EF 100-400mm f/4.5-5.6L IS USM, has anybody out there got this lens, is it worth the money and the upgrade? Also will this give me enough reach for Bird telephoto photography? Or will I need a Converter?
Will the converter have any effect upon the image quality?
Thanks

Hey trebor,

It's definately a good upgrade, giving you that extra 100mm to reach those birds. Not only will you achieve greater zoom, but you'll notice that your images will be pin-sharp, as oppossed to the 75-300mm lens. It's not a very fast lens, and definately performs better in good lighting conditions, but then again, you're probably used to that with your existing telephoto. (Keep in mind, that the Image Stabilization is going to 'effectively' turn your 4.5 lens into a 2.8 )

I've had one user claim that his images are crystal clear at 395mm, but not as clear while at the full 400mm... I have yet to see this for myself, but worth playing with once you own it (or even before for that matter). I've also been cautioned about the pull-style zoom. Apparently it can create a vacum and pull dust onto the sensor... again, I have yet to see this. I know many people with this lens who have never made that complaint; however, it would seem logical given the pull-style zoom mechanism.

This lens is my next purhcase, so I've researched it carefully (based purely on discussions with current owners of the lens and on their experiences) - you get to see a lot of these lenses at the bird sanctuary. It sounds like a solid purhcase and an excellent upgrade from the 75-300 (which is the same jump I'm making).

All and all... it's a Canon L-series lens... you can't go wrong! (and it's sexy)

Oh BTW - with regards to the teleconverter... Canon makes a special one for this lens specifically... I'd stay away from third-party manufacturers to ensure you don't lose your auto-focus and to maintain optimal image quality. Don't buy more than a 1.4 converter.

Hi Pete,
Thanks for the detailed info - you've convinced me!
Thanks again