I'm currently looking at a couple different lens options and right now I'm between a Canon 70-200L F4 IS USM and the Canon 100-400L F5.6 IS USM. I'm really not sure if I need it to reach out as far at the 400, but it would be nice at times. Anybody have any thoughts?

70-200. Great focal lengths. Having that extra reach of a 400 would be nice but you might find yourself limited if it is your first long lens. Plus at 5.6 it is a really slow lens. Probably would find yourself in more situations where you needed that extra light.

That's understandable. As for the 70-200, I know the 2.8 is insane, but the 4 is much more in my price range, in your opinion, which would be better for shooting mainly outdoors? <BR> <BR>I figure with either of these, I could also add an extender to get that extra bit of range, but that really slows things down too, so many options....

I have somewhat of the same delima, I have decided on the 70-200 F4 but can't decide on the IS for the extra $400. Pro's / Con's???

Pro's of the f4 L IS: <BR> <BR>IQ (especially at f4) - best of all the Canon 70-200 L's. <BR> <BR>IS, which can really help get keepers in some situations and with teleconvertors onboard. <BR> <BR>IQ with a 1.4X TC onboard is unbelievably good and doesn't slow the AF down at all. <BR> <BR>I had a pretty good 100-400 but it didn't have that IQ "POP" that you'll get with the 70-200. The pump zoom is OK once you get used to it but will never be as fast as a twist zoom IMO. Since the 70-200 with a 1.4X on is still better IQ wise then a 100-400 and smaller, I'm pretty happy now just owning the 70-200 and my 400 primes to cover those ranges. <BR> <BR>(Message edited by richd on October 19, 2008)

i have owned both the 70-200 f4 and the 70-200 f4 IS. <BR> <BR>the IS version is worth the extra money in terms of image quality. it is also a very light weight lens. <BR> <BR>if you dont shoot a lot with a big zoom then then the non IS version is still a awesome lens and a bargain at $600 new ( i shoot 80% of the time with my 24-70 f2.8 )