Buy now or wait?

[Loswr]

Having said that, the 70-300L vs 100-400L is a difficult choice. The 70-300 has all the improvements in IS and AF, but you lose the long end. I want to get one or the other at some point for sports (cross country, track). Anyone have experience with both and have suggestions?

Fundamentally, I think it's not as difficult as it seems - it comes down to whether or not you need that extra 100mm (and secondarily if you want to be able to attach a Canon TC). If you do, the 100-400mm is the better choice. Else, the 70-300mm is a nicer lens. I used a borrowed 70-300 L for a little while, and it handles very well - the compact size is nice, the IQ is excellent. I've considered getting one to use for in inclement weather (vs. the 70-200/2.8 IS II + 1.4x/2x TCs), and possibly for travel use as a compromise between the two larger/heavier white zooms. But since I swapped my 300/4 IS for the 100-400mm specifically to get the extra 100mm, I can't see the 70-300mm as a replacement for me.

As for sports use, both lenses are f/5.6 at the long end. Probably for running events, which tend to be daytime where you can hope for good light, it's ok.

 

[wickidwombat]

Thanks neuroanatomist, that's the kind of info I needed. I feel much more informed now. That article even made me reconsider purchasing the 100-400mm f4-5.6L. Seems to make more sense to go with the 70-200mm f/2.8 as planned then use the money I was going to spend on the 100-400mm to buy a second camera body to keep a second longer or larger aperture lens mounted.

This is my philosophy I have the 70-200 f2.8 IS II on my 5Dmk2 and keep the 300 f4 IS on my 1D mk3 awesome combo IMO and i keep the 1.4 teleconverter in my pocket incase i need a little more reach on the 300.
the things i love about the 300 f4L IS are its light, its skinny (I take off the tripod mount dont need it and it takes up space. the built in hood is great its fast both in aperture and focus speed. definately consider this lense with a TC in place of the 100-400 if you are considering having a 2 body aproach.

I have been considering getting a 7D to keep attached to the 300 for the extra reach and the fact they ar eso cheap now but all the reports of bad high ISO performance has me thinking i might wait and just deal with the extra weight of the 1d 3 and the different batterys for a while longer because i like being able to shoot at 1600 iso and even 3200 at a push and it sounds like the 7D really struggles in this department

 

[tron]

I guess it depends also on how light you want to travel. I have just bought a 100-400 (yes I know perfect timing, just before the next
version was announced!) and although it will overlap with my some of my lenses (70-200 f/4L IS, 300mm f/4L non-IS, EF1.4X II)
I do not regret it. I will be easy on some occasions to just grab my 24-105 and 100-400 and go...

 

[tron]

I guess it depends also on how light you want to travel. I have just bought a 100-400 (yes I know perfect timing, just before the next
version was announced!) and although it will overlap with my some of my lenses (70-200 f/4L IS, 300mm f/4L non-IS, EF1.4X II)
I do not regret it. I will be easy on some occasions to just grab my 24-105 and 100-400 and go...

Let me correct myself: Just before the next version was rummored not announced! It is different! Plus the price of the new lens (if indeed 2800$) would be way off.