what's it like to hand hold at 400mm?

ie, should i forget about using it without a tri/mono pod?

Heavy! But not unmanageably so - I use it handheld all the time and find carting a tripod around rather cumbersome. That's what IS is for, after all.

Wot he said ^^^

Very well balanced hand held.

I use a monopod a fair bit and it works well with that combo - takes the weight if you are in one position for any length of time (ie waiting for something to shoot)

Not using mine on a 1D (I've got a 5D), but I find I can usually hand hold it at 400mm when the IS is turned on. When it's windy (or I'm tired) a monopod does help...

Agree with the above - I only bother with a monopod if I'm holding it to my eye for a while, otherwise hand held is fine.

I never carry any support (too lazy) but I have some decent shots with the lens at full whack. I have only a 350D though. As the others have said, conditions do play their part - and the wind can be a problem.

But it's relatively light in weight and even for a scrawny git like me, I can manage it for a full day's worth of shooting.

This pic, scaled down is at 400mm, handheld, in windy conditions at Newport Wetlands.

http://img.photobucket.com/albums/v655/MiltonMallard/IMG_0804resized.jpg

And this is the subject, from the same pic, cropped and sharpened a bit.

http://img.photobucket.com/albums/v655/MiltonMallard/IMG_0804cropped.jpg

A nice pair (of gadwells).

So you can see, it's a great lens... but, if there's natural support, or a hide, I'll still use it, as it improves clarity further.

excellent, cheers.

I'm off to the states early next month, so was thinking of making use of the cross rates :)

started thinking about the 70-200 IS f/2.8 too :(

is a 70-200 still okay with a x1.4? can i still use autofocus?

I think so. It's the darker lenses that have a problem - that should be fine.