Hesitation 70-200 F4 L ou 70-300 IS USM ?

[fmangeant]

euh ... je susi pas bien sur que recadrer sur un capteur 12 Millions de pixels améliore les choses, j'ai cru lire de tres mauvaises critiques sur le capteur du 450D mais je laisse au specialistes de confirmer ou pas ...

"Très mauvaises critiques" ? D'après dpreview.com :

Pros : Superb resolution, good per-pixel sharpness (especially in raw files)

Conclusion : Canon may no longer be the automatic choice for the entry-level SLR user, and I possibly wouldn't recommend it over a Nikon D60 or Olympus E-420 for absolute beginners or anyone wanting 'point and shoot' access to well optimized JPEG ouput. But if you want to move to the next level of image quality and performance, and are prepared to take control of parameters (and ideally shoot raw) to get the best possible results, the EOS 450D is an easy recommendation.