Take one telephoto lens for wildlife such as 100-400, and wide-angle for landscape, you should have many choices.

I don't have one yet but I am seriously considering it. The reviews I've read on this lens have been very favorable.

For stock, lenses like that have a far too wide range > color aberration - vignetting - softness - speed. Stock has much higher technical requirements for the image than assignment or editorial, even print.
You're better off with a 50mm prime for models, and something 100-300 for tele. You can replace the prime by 18-50 or 18-70 when you like landscape and models both. One size doesn't fit all in stock, alas.

I own the kit lens that came with my Canon Rebel XS, and I was wondering which type of lens I should add if I plan on doing some outdoor photography.  I want to go to a local national park, and I'm split between buying a telephoto lens and a wide angle lens.  I don't have a ton of money, so I'm only going to buy one new lens this summer.  Any suggestions?

You didn't say what you budget is, so that makes it hard for me to give you advice on a lens.  I own the Canon 17-40mm f/4L ($700) and it is a nice lens that is good for large landscapes and big skies.  I bought it in particular for waterfalls because many of them are large and I can't get back far enough to include the whole waterfall in one shot.  I recently purchased the Canon 24-105 f/4L IS ($1100) which is a good all around lens.  I also own the Sigma 70-300 f/4.5-5.6 APO DG Macro lens ($180) that isn't as good of quality as the L lenses.  It's noisy, slow to focus, and isn't as sharp, but for the price I think it was a good buy.

I would recommend staying away from lenses that have a large telephoto range as they tend not to be as sharp.

I use Tamron SP AF17-50mm 2.8 I shoot real estate, landscapes,isolated product photography 

So are wide angle and telephoto just the same lens?  There isn't two separate lenses for each?  It's just the specs I need to be looking at...

Yes one lens which is able to go as wide as 17 mm up to 50mm with a fixed fstop of f4 or 2.8

When you are using the lens 28-135 3.5-5.6 at its shortest focal length (28mm) the aperture is indeed f/3.5--a fairly fast lens. But as you zoom out toward 135mm the lens speed decreases and you're shooting with an f/5.6 lens

I hope I explained it correctly

I highly recomend start with some reading, its obvious you have no idea about lenses. Its hard to choose something if you dont know what you want.

For budget/quality compromise its probably best solution Tamron 17-50/2,8 and for tele Canon 70-200/4, both not really expensive and both pretty good.

Canon also makes a 28-200mm lens you could check out for under $400.  There you have the 28mm which would be a nice wide angle for nature photography and a 200mm if you wanted to zoom in on something.  It would be as high quality as if you bought a lens with shorter zoom but if you want just one lens and was to spend under $500 it could be a good choice.

Canon 28-200mm f/3.5-5.6

Quote from: leaf on May 05, 2009, 02:30

There you have the 28mm which would be a nice wide angle for nature photography and a 200mm if you wanted to zoom in on something.

28mm on a Rebel is not that wide for landscape I would say. A Canon or Sigma 18-200 or the Tamron 18-270 are probably better suited, at least from a focale range point of view: there is a huge difference between 18 and 28mm.

ah yeah, you are right.  i didn't even know canon made an 18-200.  If your main concern is being able to shoot 'everything' that would be a better lens choice.

Xalanx: I disagree, sorry. Best price/value wide lens is Tokina 12-24/4 which smashes Canon EFS 10-22 into pieces and still costs HALF! EFS 10-22 is way overpriced lens with average optics, I dont see any reason to pay 100% more then for Tokina 10-17, Tokina 12-24 or Sigma 10-20 to get disputably same or even worse quality. Check eg. dpreview.com to see detailed tests and reviews.

I wouldnt choose ultrazooms like 28-200, 18-200 etc. as they MUST be compromise in optical quality. Really noticable CA, distortions and not really good sharpness are absolutely normal with them and with ultra-pixel-peepers inspecting photos on micro insanely even over 100% is this big problem. Good zoom lenses cost about $400 and up for each and I dont think that set Tokina 12-24/4 + Tamron 17-50/2,8 + Canon 70-200/4 for about $1100-1300 altogether is too much. You would pay 2-3x more for original Canon lenses to get about the same quality.

Btw. absolutely best lens for outdoor photography is Zuiko 12-60/2,8-4,0 SWD but that doesnt fit to Canon  Choosing basic zoom for APS-C Canon is a really big problem, as there are no really best options, only compromises. Its pity the biggest DSLR producer in the world wasnt still able to deliver suitable zoom, only way overpriced stuff like 17-55/2,8 and EFS 10-22 with disputable quality and pretty bad focal length for 17-55 (there is NO tele starting under 70mm except Tokina 50-135/2,8!)

I shot with 10-22 and with tokina 12-24 and with the new tamron 10-24. So I'm speaking from personal experience. And my opinions are quite close to what the review sites are saying. photozone, fredmiranda, etc.

Things are like this: 10-22 beats tokina (not to mention sigma) in sharpness and distortions. Tokina would have been good if it wouldn't have been so catastrophical regarding chromatic aberrations. It's simply annoying. And it's noticeably softer in corners than the canon. Yea sure you can fix some of the CAs in lightroom or camera raw in PS. But I'd rather prefer not to. Also if you shot in the smaller focal length (12mm) you can get purple fringing in the left side of the image and blue fringing in the right side

the tamron 10-24 is the "el cheapo" version of canon 10-22. Unfortunately sharpness and CA performance are nowhere near the Canon. It's a compromise, if you want to pay less. But you get what you pay for.