Why does it happen that when I take a picture of some product or person, only one portion is sharp and the rest gets hazy. I was facing this

we are often fascinated by the long white (actually a light grey or beige) lenses from Canon. These white lenses are all large...

Some lenses are slower than the others. However, there could be a few possibilities. The lenses generally are unable to focus on plain...

Some lenses are slower than the others. However, there could be a few possibilities. The lenses generally are unable to focus on plain...