Sigma Lenses For Canon 50d
Tamron 18-270mm or Sigma 18-200mm or 70-200mm?

I have a Canon 50D and currently have 2 lenses, 50mm f/1.8 and 17-50mm f/2.8 and planing for a canon 60mm f/2.8 macro soon. so my question is that I get the 18-270mm, 18-200mm or 70-200mm lens for my next? Are different major? that you think will better photos? here are some links to the objectives they spoke: http://www.amazon.com/Tamron-18-270mm-3-5-6-3-Aspherical-Nikon/dp/B001DYC0CS/ref=cm_cmu_pg__header http://www.amazon.com/Sigma-18-200mm-3-5-6-3-Optical-Stabilizer/dp/B000NOSCGM/ref=cm_cmu_pg__header http://www.amazon.com/Tamron-70-200mm -Macro-Digital-Cameras/dp/B0012GLHL2/ref = Cm_cmu_pg__header Thank you thank you

With the lenses you already have I guess the quality is what you are after and that quality is more important than comfort. If that is correct then there is no doubt that the three objectives that the list will be more happy with the Tamron 70-200mm (although there are other options that I have not listed). Why? The two other objectives that list are good and desirable, are the type of lenses you would use every day when you go out with the camera and only worry about anything else. They adapt quite well (especially over the Tamron) so that they can throw at them. However, the quality is not going to be perfect, both in the wide end and eventually going to notice on TV that the issues insignificant results. The 70-200mm that lists a much better performance is lower throughout the zoom range, with far less distortion at both ends of its range. If I'm wrong and really want a lens that does almost everything, but at a cost of some quality then go with the Tamron 18-270mm. It is a very "convenient" target to have!