Just hired a lens Canon 100-400 is l

[Mike.P]

I have the 100-400mm and 400mm and take them both when going to an airshow. I tend to use the zoom for prop planes, helicopters etc and the prime for anything moving fast. I prefer the flexibility of the zoom but the prime is certainly sharper even at f5.6.

Couple of shots with the 400mm 5.6 on my 7D

BAC Jet Provost - Bournemouth Air Festival 2013 by Mike.Pursey, on Flickr

Tucano - Bournemouth Air Festival 2013 by Mike.Pursey, on Flickr

 

[thatone1967]

What I really need, more than anything, is the L series glass, rather than Image Stabilisation.

 

[RichardTaylor]

The Canon EF 400mm f/5.6 L USM lens doesn't have image stabilisation.
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Is it a need or a want?
I know lots of guys who shoot without L series glass, and come back with great results. Most of them are Nikon shooters. I sometimes do it myself, with Canon cameras, depending on what and where I am shooting.