Quote Originally Posted by mike_d


Ahh... That makes sense. Yeah this lens will be used for my sons soccer but for other things as well that is why i thought the 70-300 IS would be good too because it has the IS and the lower end L lens doesn't.
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<span style="font-size: 9pt; color: #000000; font-family: Verdana;"]The IS will be great for the "other things" but for sports such as children&rsquo;s soccer you'll probably want a shutter speed at around 1/250 to stop the action. At shutter speeds that fast the IS won't be very helpful but if you are taking shots of the huddle or where the subjects aren't moving too quickly the IS will really shine because you'll be able to shoot at speeds at around 1/30 which is way too slow to handhold the 70-200 f/4 non IS. Some people can hand-hold at slower shutter speeds but the rule of 1/focal length is a great rule of thumb. Remember that rule was created based on 35mm film/sensors so you will need to apply the 1.6X FOVCF to your Canon T1i. Here's an example:<o></o>


<span style="font-size: 9pt; color: #000000; font-family: Verdana;"]To hand-hold a 200mm lens on a 35mm sensor you would need a shutter speed of 1/200<o></o>


<span style="font-size: 9pt; color: #000000; font-family: Verdana;"]To hand-hold a 200mm lens on a 1.6X FOVCFsensor you would need a shutter speed of 1/320 (200 * 1.6)