I'm looking to buy a new lens or two for some baby photography I'm planning on shooting soon - with natural light only. I'd also like to use these lenses for a Colorado vacation in a week and some indoor/outdoor sports photography. After reading tons of reviews, I've been bouncing back and forth with a lot of these, and would appreciate any input! (I'd like to stay under $1000) Tamron 17-50mm f/2.8 Tamron 24-75mm f/2.8 Canon 85mm f/1.8 Canon 70-200 f/4L 1&2. Is the 17-50mm worth the extra cash over the 24-75? 3. Can I get away with using my 50mm f/1.8 over the 85mm f/1.8? If so, I can spend the cash on the other lens. 4. I wonder if there's any use for the 70-200 L lens at all in baby photography, since the focal length may be too large and aperture too small for indoors. How's the Bokeh on this? Mainly, I'd like this for my Colorodo vacation. Right now, I have an XTi w/kit lens and 50mm f/1.8. Thanks!!!