« on: November 07, 2012, 10:57:40 PM »
First off, if i understand this correctly then f2.8 on 7d is more like f2.8*1.6 = f4.4ish on FF. Appreciate it if someone could correct me on this.
I think you are correct. The light gathering is the same for the lens, if they are the same focal lengths. For instance, a 31mm or 30mm lens on crop sensor will gather the same light as a 50mm lens on full frame, at the same aperture. If you are using the exact same lens for crop sensor on a full frame camera, the focal length would be wider and more light will be gathered. The bokeh or out of focus blur would also be affected by the crop factor.