Understanding Aperture (F-stops)
Aperture is the size of openings in the lens.Its an adjustable hole in the lens,Its just like human eye,we need to open more eye to see in low light and need to shrink pupils in more light.it can be narrowed or widened to control how much light passes through the lens.
Aperture is measured in or denoted as F-stops.f/2.8,f/5.6,f/16.
Larger aperture means opening is large like f/1.4
Smaller aperture f/16 small opening
Smaller the f-stop no. the larger the aperture.
In the darkest environment we need to open the aperture and in situation of bright sunny day we have to close the aperture ring to desired no.
Above pictures clearly shows when we click at large aperture opening ie f/2.8 more light entered into the camera results it burns the image and make it over exposed.While at f/8 we got optimum exposure and got clear picture in terms of light & colour.Otherside when we clicked at f/22 then it makes picture darker because of smaller aperture opening causes less light enters into camera.
Diffrent lenses have diffrent aperture openings all depands how your lens is manufactured.