What is a Low Light Lens? Well it is more of a term that we have used to describe a lens that is more able to handle darker situations than say a kit lens. This means that the maximum aperture (the size of the whole that light passes through) is bigger (a smaller number as it is a fraction of 1. ie f4 is 1/4 f8 is 1/8th is a good way to think of it) so it takes less time to get a full exposure.