Get a 70-200/4 - love it, then one day really need f2.8, feel
dissatisfied, buy a 70-200/2.8. Later feel the need of IS and upgrade
to the IS version.
Also get the 24-105/4 - love it, then one day really need something
faster, get a 24/2.8, 50/1.4 (preferably a Zeiss), plus an 85/1.8. But
keep the IS zoom.
Then one day see what an 85/1.2 can do, feel dissatisfied with the
85/1.8 and upgrade to the L version.
Also notice how abysmal the 24/2.8 is, and upgrade to the L. Then one
day really need something wider than the 24/1.4 and feel dissatisfied.
Look around confusedly. Test some bad Canon zoom lenses and feel
dissatisfied some more. Someone shows you a Zeiss 21 and you buy it
becuase it makes your work look wonderful. But feel a bit dissatisfied
with the waveform distortion.
Then one day you make the mistake of trying a 135/2 and of course you
have to have that.
Then one day you need something longer than the 200/2.8 IS and you buy
the 300/4, but it doesn't have IS, so you upgrade to the 300/4 IS.
Then you find that you're not using the 70-200/IS much because it's so
big and heavy, so you buy a 70-200/4 because it now seems so light and
sharp. And you sell the Zeiss 21, too, because it's worth so much
money now, and it doesn't render straight lines. And someone tells you
that the 300/4 non IS is much sharper than the 300/4 and you're not
sure whether to believe them, but it makes you feel slightly
dissatisfied with the IS version.
Then you think: wouldn't it be great if I could sell all this junk and
just buy one really great long, fast zoom lens? And you look hard at
the Sigma 120-300 f2.8 and you try it but it's too heavy and that
makes you feel dissatisfied.
So you look at the 100-400IS and you think: that's the answer to all
my problems! But you try it and you find it's not very sharp and that
makes you feel dissatisfied, so you get a Sigma 100-300m f4 and it's
great! And you use it a lot but eventually it makes your arms tired
and it's soft at the long end and it doesn't have IS and that makes
you feel dissatisfied.
Then one day you have to do a shoot in the rain, and you worry about
your 5D because it's not weatherproof (and that makes you feel
dissatisfied) so you try the 1Ds II and it's GREAT. And then you find
that none of your wide angle lenses are sharp in the corners and you
wish you hadn't sold your Zeiss 21mm and that makes you feel
So you sell everything, go on holiday, come back and buy a 350D with
the 17-85IS lens and find that it does almost everything you need it
to do anyway, except the viewfinder is rubbish (and guess how that
makes you feel?) and it's a bit flimsy, and then you start to think
the long end isnt long enough and then someone tells you that the
Sigma 18-50/2.8 is a lot sharper, or the Tamron 28-75mm and you read
all these posts praying for Canon to release the new lightweight full
frame 17-300mm f2.8 L IS but that just makes you feel dissatisfied
becuase it turns out to be just a rumour, and then you decide to take
up painting. Enjoy.