Sorry about the long post. Due to finances this will be a few months away so I've got all the time in the world to think about it, but i want something with a bit more reach than my 70-200. I'm currently considering:
Canon 300 f/4L IS
Canon 400 f/5.6L
Canon 100-400 f/4.5-5.6L IS
Tamron 200-500 f/5-6.3 Di LD IF
While the shortest of the bunch, the 300 will have the best IQ, widest aperture and IS.
The 400 will reach a little farther, and still have wonderful IQ, but lose a stop and IS.
The 100-400 still has great IQ, a reasonable wide aperture although not fixed, and IS but is the most expensive.
The Tamron wont quite match up optically, but would be the most versatile focal length as its the only zoom and the cheapest of the bunch. Does anyone have experience with this lens? (I don't know much about tamron)
These lenses are all in the 1000 dollar range give or take a couple hundred, if there are any other lenses i should consider, throw them into the mix. Any and all input is appreciated.