Quote Originally Posted by bburns223
the 300 f/4 is as sharp at f/4 as the 100-400 at 300mm f/5.6. Plus, the 300 f/4 is $500 cheaper.
Quote Originally Posted by neuroanatomist
...but, the 100-400mm achieves 400mm f/5.6 with better IQ than the 300mm + 1.4x TC, and provides the ability to go shorter if necessary.

This has been one of the more heated debates on the forum next to the 70-200mm f/4.0 L IS vs the 70-200mm f/2.8 L IS, small pixel IQ vs large pixel IQ, the EF 24-70mm f/2.8 L vs the EF 24-105mm f/4 L IS, etc, etc. Let's not lose site that ALL Canon <span style="color: #ff0000;"]L glass is outstanding! We're lucky that we have so many options to agonize over. In the end you choose the tool that you feel will help you achieve your photographic goals. It's hard enough comparing zoom ranges of the exact same focal length (see above) let alone primes vs zooms. If you're the one doing the buying then choose the tool that you feel will help you achieve your photographic goals. Getting opinions from the members of this forum is probably the best thing you can do (after reading all of Bryan's reviews 1st!) to help you determine what will best suit your needs. For some of us that will be the EF 24-70mm f/2.8 L. For others it will be the EF 24-105mm f/4.L IS.


Sorry for the off topic rant :-)