What’s a lens hood? A lens hood is the plastic tube that you attach to the end of your lens. Today, most DSLRs come with a hood however most amateur photographers don’t seem to know what to do with it. We're here to tell you to
USE THEM! Just attach it to the end of your lens and off you go! So why should you use your hood? The answer is simple because it (generally speaking) doesn’t do any harm to your image however not having it can sometimes have ill effects. The purpose of the hood is to create a shadow over your lens from bright light sources like the sun or spot lights. When these light sources hit your lens at odd angles it may create lens flare which will give you either strange bright spots on your image or a dull looking image.
If you do not have a lens hood you might consider buying one. Be sure to choose the one that is specifically designed for your particular lens. IF you have the one designated for your lens and you notice that the corners of your image are dark or black, this is because you either have the wrong hood or you have mounted it improperly. Just remount it and make sure that it is seated properly.
If you have a small point and shoot or a lens that you are unable to attach a lens hood onto, simply use your hand to create a shadow over the lens. Simple!