I've a Tamron 75-300 LD , it's a nice lens.
But on many reviews they say Sigma's is better.
I also have Tokina 28-70 for my Canon 300D as well but end up 28mm is not
wide enough after 1.6X factor. So, I need to buy a Tokina 12-24mm for
landscape shot. If you not going to spend any more for lens in the future. I
suggested you buy 18-200mm lens otherwise you should get two lens instead
for better optic result. But I'm sure you will found 28mm X 1.6
( =45mm ) is not wide enough for everyday use.
Hope it's help.

JL

Stick with Canon lenses.

*****************************************************

"Vietnam is what we had instead of happy childhoods."

                            Tim Page in
                            "Dispatches"
                            by Michael Herr

AFAIK the auto-focus on your 350D will not work for lenses lower than F 5.6.
And 11x zoom?? Can't be any good, can it?

Better, but Canons L lenses are the best... But require a lot of $$$ :-/

For a new comer I would advise the AF 18-200.

Reasons :
1. single lens you do not have to cary more than one lens.
2. You do not have to change lenses which reduces the dust problem.
3. 18 mm (1.6 times results in 29 mm) which is a nice Field of View to have.
   28 mm (1.6 times results in 45 mm) this is not enough wide angle.
4. One lens has only one size of filterthread so no double filters (pola for
example)
   are needed.

Two lenses will probably have more quality, but how much quality do you
need.
If you can't decide that before hand you might as well start of with the
single
lens and if that does not give you enough quality go from there.
(Going from two lenses and deciding that you need more quality does not
make making decisions easier).

Because I allready had some lenses from my previous camera's I now have
ended up with three lenses. With quite some overlap and sometimes I wish I
just had one single 18-200.

Ben

What made you choose Canon? Have you purchased the body yet? What don't you
like about Nikon's offerings?

If you are a beginner I strongly recommend you get the Tamron 18-200 and
don't look back.
The Canon is as good as any digital SLR for your purposes.
Because this lens and camera combo is easy to use you will use it to make
more pictures and the more pictures you make the more you will learn. There
is no other way to know if you need or want other lenses. The most important
thing in learning photography is to make a lot of pictures and not worry
about changing lenses, which is better, etc. By modern criterion the lenses
e.g. Cartier-Bresson used were terrible but I would venture he was a better
photographer and made better pictures than almost any troll on this
newsgroup, including moi.
The Canon dSLR kit lenses basically suck anyway: they are the poster
children for chromatic and linear distortion. The Tamron is no worse and
probably better at the wide end and very good at the medium and longer
ranges for all practical purposes.

If you are looking for a single-lens solution, and are not committed to the
Canon body yet, you might want to investigate the Nikon D50 + the new 18-200
image stabilised lens. (Where I am the prices work out quite close for this
against the 350 + Tamrom 18-200, might be different where you are)

So what kind of photography do you do, and how high is your
budget?

1. Lenses with a large zoom range only get that by
  sacrificing something, e.g. speed, quality, ... but mostly
  quality.  
 
  Ok, there are some which don't sacrifice quality that much, e.g.
  Canon's 28-300mm L lens, but ... where other 28-300mm
  lenses cost $260 or $400 (USD, adorama.com), you pay $1900
  (refurbished) to $2200 (new) for that one.

2. The reasons you'd want a single lens with a huge zoom
  range --- even though it diminishes image quality --- are:
  - convenience (Not lugging around many lenses e.g. during
    hiking or holidays)
  - environments rather averse to changing lenses
  - needing to switch between tele and wide angle immediately.

3. You are aware that 28mm will only give you a viewing angle
  of a 45mm lens with the 350D?  (1.6x crop factor)
  If you want wide angle at all, that's _bad_.

We need your budget and what you shoot.  BTW, have you bought the
camera, if not, why did you choose it (this may give insights if
there isn't a better matching camera for you)?

If I was you, and really had money, and would shoot all round,
I'd probably take
- a 20D or 30D (depending on the budget), or even a nice 1D :-)
- the vertical grip (with an extra battery to fit)
- a good  flash (550/580 EX) or two (add one or more 420/430/550/580,
 depending on budget, for slave operation)
- A good charger and enough batteries for all these flash units
- a few *light* tripods (for the slave flashes!)
- a sturdy, yet lightweight tripod with a good head (for the
 camera)
- a fast low-light lens, e.g. 50mm f/1.4 (the f/1.0 is a bit too
 expensive :-)) or 35mm (which looks more like a classic 50mm
 on a 1.6x crop body)
- an 10-22 EF-S for all your really wide angle needs (16-35mm
 equivalent)
- a 16-35 f/2.8 L or 17-40 f/4 L for those wide-angle to normal
 wants
- a 70-200 f/2.8 L IS for nice tele operations
- a teleconverter (1.4x, and probably 2x too) for that 70-200
- a couple memory cards and a fast card-2-HD system for
 unloadingtake
- maybe even a nice 400 or 500 or 600mm --- if I needed it
 and had the money.
- add in a real macro with 1:1 capabilities --- maybe even a
 macro flash for it.  Failing that, a 250D or 500D acromat and
 rings can give some macro capabilities, as well.
- oh, a replacement focussing screen might be nice, too.
- Don't forget a large and comfortable bag, one to take all your
 stuff -- and you probably want to rest the weight not only on
 your shoulder.  A backpack is good for that, but a top-loading
 bag with belt allows you to balance the weight and get and
 change gear on the go.
- probably a polarizing filter could be useful.
- don't forget a good RAW converter and time to polish your
 images.
- you _really_ need a back-up policy in place and working,
 lest you loose your precious images.
- There are lots of other things: tilt-shift lenses, soft lenses,
 200mm f/1.8 lenses :-), more non-tele IS lenses, ...

That being said, the most important thing is experience.
(Just look at what the photographers had to work with 50, 70,
100 years ago --- and some of the images are still hauntingly
perfect!  Ok, most of the bad ones never survived.)

The second most is liking your equipment, even if that means
buying only one *good* lens --- that may even be a non-zoom
(which is _usually_ sharper, contrastier, faster, lighter and
cheaper, too).  A lens you don't like you won't use, so it's
worth nothing, no matter how cheap.

The third: No matter what equipment you get, somebody will
trump you --- even if you buy a xxxK$ xxxMP digital back on a
medium or large format camera and extreme $$$$$ lenses.
Don't let that turn you off.  Learn the limitations of your
gear, then learn to work around them and with them.  It's
dark?  Use a flash.  Don't like the red eyes?  Bounce the
flash over the ceiling and/or use slave flashes.  Can't use
flashes (e.g. museum or landscapes or too foggy air)?  Try a
tripod, monopod and/or IS, try with higher iso, use your fast
lens, etc.  Go to point 1 and get experience, or at least
ideas from how others do things.  Think about framing ---
everything in the center is ... suboptimal.  Think about
using light, colour, shape, form, diagonals, ...

-Wolfgang

Canon efs 17-85 IS.

It might be the only lens you need.  Mine is on my 20D most of the time.  (I
have 5 other lenses)

I think that it is important, when changing camera systems completely,
that you lose as little as possible. You've become accustomed to
certain things, and you come to rely on them, whether or not you
realize it.

The S5500 has a few things that you might have become accustomed to
that are worth pointing out:

-a 37-370mm (35mm equiv.) zoom range
-a 2.8-3.1 max aperture
-4 Megapixel

Obviously, the larger chip, faster performance, and reflex viewfinding
of the XT (or 20d... which doesn't cost too much more and is much
"nicer") will give you a significant improvement, and the 8 megapixels
will give you more to work with in post. This is important to think
about.

The concern here is that you're looking at an 18-200mm lens that would
give you an effective range of 29-320mm. A loss on the telephoto end,
but to be honest, a very small one (30mm at that end of the zoom range
is a minor difference). So the lens may feel like a good replacement
for the ranges you're used to, but consider the aperture. The tamron
opens up to a 3.5 on the wide end (meaning you lose 2/3 of a stop) and
a rather-ridiculous 6.3 on the tele end (meaning you lose two stops
from what you're used to). This is not an insignificant amount of light
loss. As some have pointed out, autofocus might not even work at the
tele end of that lens, where it is arguably most essential.

This concern alone should rule out the 18-200. Pictures you're used to
getting will be lost simply because you don't have the light. Even if
you do, loss of autofocus could make those pictures unusable.

If you've been happy with the wide end of your lens, and see no need to
go wider, you can look for a lens that has a 24 at the wide end. This
suggests the Canon 24-105 f/4L IS, which would effectively be a 38-168.
168 is plenty long, you'd lose only a stop at the wide end and even
less at the long end, you'd more than get that back with IS (except for
depth of field, though with the larger chip you're probably still
better off if you like to throw the background out of focus). If you
occasionally need to get closer, you can crop and probably still have
an image larger than the 4MP you've been using. You'd also have a
fantastic lens that would last a long time an retain its value. I'll
say nothing about the quality of Tamron and Sigma glass (okay, I'll add
that build quality is generally shoddy), but they certainly don't hold
value.

Do you need to get longer because you shoot tele most often? Then
consider something else (perhaps the 70-300 4/5.6 IS, or the 70-200
f4L), and also get a wider lens.

I'll sum up anecdotally by saying that when I bought my first SLR, I
opted for a slow sigma superzoom (28-200) and my pictures suffered. It
wasn't until I bought a fast 50mm prime that I began to get great
pictures. Loving, as I do, that kind of shooting, I recently found it
necessary to grab a 28mm 1.8 prime that I could use as a fast normal
prime on my 20d, in addition to my other three lenses. I'd recommend
it, but that kind of shooting may not be for you. Consider it.

But I'd reckon that a 6.3 aperture is a kind of shooting that is even
less for you.

Research your glass and don't get cheap. If you're already spending all
of that money, spend the little bit more that you'll need to get a good
lens. The analogies of expensive cars and cheap tires aren't just a
joke or hyperbole; the lens makes the picture at least as much as the
camera does, and I'd say considerably more.

I'll close by saying that others' suggestions of investigating other
camera systems is a good idea. I wrote speaking of Canon both because
you stated the XT and because I have Canon gear. But Nikon has some
great options, and Pentax has alot going for it as well (both offer
less ability to regain lost telephoto reach through cropping, however).
If you view the camera as merely a box to hang a lens on, it make sense
to find the lens that will work best for you and then consider which
box offers enough features to get great pictures from that lens.

Good luck with your purchase,

Will