Whats the point of a Lens Hood?
All lenses come with one of these but whats the point? When should you use it?
When should you not use it?
It just gets in the way!
What does a lens hood do? The lens hood is designed to stop stray light getting on to the front of the lens and causing lens flare.
Why do they look different? Generally speaking a wide angle lens will have a hood with a wavy edge and a telephoto lens will have one like a tube. The key thing to understand is that the lens hood is designed for and is right for that lens and if you ever need to replace it then you need to get the correct one.
When should I use the Lens Hood Almost all the time as it has a number of advantages and roles a.- It will stop lens flare b - It will protect the glass at the front of your lens - big positive c - If you are working fast and changing lenses and you bag can manage it then you don't need to refit the lens cap when you put the lens with the hood fitted in the bag (does depend on how well organised your bag is and what you are doing) d - To get it out of the way! Typically the lens hood will come fitted to the lens but the wrong way round which is to aid storage. If you leave it like this it hinders how you hold and interact with the lens, so by not fitting it it becomes a problem.
When should I NOT use the Lens Hood a - When using a built in flash on a DSLR style camera as the lens hood will cast a shadow b - On a studio or portrait shoot as it can make a lens intimidating c - When you need to be unobtrusive as removal of the lens hood will make the lens less visible