Quote:
Originally Posted by
AHorseNamedJeff 
New lens hood just arrived. Heres a little comparison of before and after:
Because of where you are aiming, these two shots are exposed differently. The second one is slightly darker and the sky isn't blown out because you are pointing more towards the sky and the camera adjusted the metering. It's also steady so there's no motion blur, and that makes it look clearer. Otherwise I don't see a difference, and that makes sense since it looks like you are standing in the shade.
A hood only has an impact on your image if you would normally have light reflecting off the front element or filter of your lens if the hood wasn't there (look at the front of your camera, is the lens glass in light or shadow). It eliminates lens flare/glare from the sun or street lights outside of the image area by acting as a well engineered shade that will cover the lens as much as possible without getting in the way of the image (less so on zooms because it can only shade enough for the wide end of the zoom). In a pinch if you don't have a hood you can do the same thing with your hand or a piece of paper, though you have to be paying attention to the glare in the first place, which can be hard through a viewfinder. A hood will also protect the lens from debris and spray though somewhat, which is nice.
Personally I rarely use lens hoods, mainly because I find many of them inconvenient to carry in my bag, and I use polarizer filers a lot, which is really difficult if you have to remove the hood to adjust it. I have payed for that from time to time with a shot lost to glare. The one time I use the hood a lot is with the canon 70-200 outdoors, because the 70-200 is very easy to accidentally pick up glare and hard to shade by hand.
Good luck exploring the camera, hope to see some cool photos posted here soon 
Edited by devwild - 3/9/13 at 7:37am