<p>I've been looking at the 70-200 F2.8 IS Cannon lens as well as the Tamron SP 70-200 f/2.8 Di VC USD for use in wedding photography and, as a sports and outdoor portrait lens. The Tamron is getting some great reviews at a much lower price point. However I am really wanting to stick with Cannon L series glass. So here is my question. If I want to save a little change on the purchase why shouldn't I go with the Cannon 70-200 f/4.0 IS instead ? We are talking one stop of light gathering. Could I not easily compensate for that by say, by bumping the ISO up one ? I have no problem spending the money for either 2.8 lens but I ask why spend the extra if one doesn't have to.<br> Thanks in advance,<br> Michael</p>
