What aperture should I use?
2) In general I always use F8 for my aperture on landscape shots, however I would be comfortable using F11 but have never felt the need to go that high. F8 extracts all of the detail that I need from my image, without causing any diffraction. Diffraction is as stated earlier, a softening of your image due to bends in the light rays hitting your sensor pixels. It can not be avoided, and the narrower the aperture, the greater your diffraction will be. Often times, beginner photographers do not realize how much Depth of Field is provided at lower apertures such as F8. They are more than adequate, and will help you achieve your best results.