Hi group,

This comes up from time to time, in fact I've just caught the tail end
of a similar thread, so apologies for any duplication, but...

I have a 10D and have been using a Tamron 28-300 zoom for just over a
year. It's not been bad, but I've had some iffy experiences with the
lens (focusing / clarity problems). Then I tried a friend's Canon
28-135 IS lens and thought the IS was *great*. So I started thinking
about replacing the Tamron with something altogether higher quality.

I've also found the 28-300 is a bit limiting on a APS-C sized sensor
such as the one in the 10D because it's not wide enough for some of what
I want to do.

I mainly do travelogue & candid portrait (ie, non-studio) photography;
also some landscape, but nothing the 28-300 hasn't been able to cope
with. I already have a Sigma 17-35 and Canon 50mm F/1.8, but neither of
these see a huge amount of use compared to the long zoom. (Needless to
say, I never have the 17-35 with me when I need a wide angle shot.) I
tend not to have a tripod with me most of the time, hence the appeal of
IS.

I'm currently considering 2 possibilities:

1) Canon 28-300 F/3.5-5.6 L IS

2) Canon 24-70 F/2.8 L plus Canon 70-200 F/2.8 L IS with extender

Neither of these options is remotely cheap, so I really want to make
sure I get this right first time! I also don't want to be buying lenses
again in 3 years or so when the 10D is old hat and I'm looking at a 16mp
digital slr for $1500

On the one hand, I like the idea of a single lens, as I don't like
changing lenses all the time (dust, extra weight, possibility of
dropping one). This puts the 28-300 in a good light. But, it's a darn
heavy lens to lug around *all* the time (for example, I'm doing candid
shots at a wedding in December). And 3.5-5.6 isn't a particularly
spectacular aperture in the scheme of things, although the IS gives you
a couple of extra stops.

On the other hand, the second option appeals because of the large
aperture throughout the range - it'd give me 24-200 at F/2.8 and 140-400
at F/5.6 with a 2x extender. But then I'd have to change lenses when I
wanted to move up and down the range. And would I always have the right
lens with me? I also like the fact that both these lenses are rated
very highly for optical quality by people who use them, and the 70-200
seems less prone to dust because of the rotational zoom action. The
24-70 would also give me a little extra space at the wide angle, but at
the same time, it doesn't have the IS which I find so appealing.
Finally, with things like weddings, I wouldn't have to lug the bulk of
the longer lens around unless I thought I was going to need it.

Does anybody have any comments on this decision, based on previous
experience with any or all of the above kit?

There is an option 3) Canon 24-70 L plus Canon 70-300 F/4.5-5.6 DO IS,
more limited but a lot cheaper, if anybody has comments on the 70-300
lens.

Thanks,
David.