as others have said, the lower the f stop the more light the lens lets in. lower is almost always better, (But makes lenses bigger and heavier). The amount of l

as others have said, the lower the f stop the more light the lens lets in. lower is almost always better, (But makes lenses bigger and heavier). The amount of light halves as the f stop goes up, but its in steps. 1.4/2/2.8/4/5.6 . so the difference is about 1/2 stop, not huge. As you close the lens iris (the f stop # goes up) you get more of the image "in focus", so focus doesn't need to be as precise. But you'll need a minimum shutter speed so moving objects in the frame don't blur. wikipedia has a good photo example of this. https://en.wikipedia.org/wiki/Depth_of_field#Effect_of_lens_aperture https://en.wikipedia.org/wiki/Depth_of_field#Effect_of_lens_...