Possible Duplicate: What types of noise can be present in digital photographs? I've few questions related to noise found in digital images. There are topics on this forum on underexposure ...
Let's say we shoot with a DSLR camera and we have two interchangeable lenses. Lens #1 has aperture f/X, X between 1 and 2 (see below). Lens #2 is f/4.5. Same focal length and other characteristics as ...