03-24-2012, 03:07 PM
Going from f/5.6 to f/2.8 will allow you to use 4x shorter exposures. But you must remember the depth of field will also change too. If that isn't too important, then also consider a prime instead. For example, a 50mm f/1.4 at f/1.4 would need 16x less exposure time than f/5.6.
<a class="bbc_url" href="http://snowporing.deviantart.com/">dA</a> Canon 7D2, 7D, 5D2, 600D, 450D, 300D IR modified, 1D, EF-S 10-18, 15-85, EF 35/2, 85/1.8, 135/2, 70-300L, 100-400L, MP-E65, Zeiss 2/50, Sigma 150 macro, 120-300/2.8, Samyang 8mm fisheye, Olympus E-P1, Panasonic 20/1.7, Sony HX9V, Fuji X100.