I have lens hoods for all my lenses. I'm in the habit of always bringing them with the lens of choice, and usually feel that it should stay on in case the shooting conditions make it necessary. From what I understand, lens hoods prevent peripheral light from hitting the lens at an angle, which otherwise can result in a blurring of edge detail.
Is this correct? How many of you always have your lens hoods on your lenses, or under what conditions do you feel they're not necessary? Is a lens hood quite unnecessary when in telephoto, say at the 40-70mm range on a telephoto lens, but quite necessary in 17mm? I have a Sigma 17-70mm, and I was thinking that since the lens extends outwards to a substantial degree, the effects of unwanted light would be negligable at the telephoto end of things.
This is my situation: I take a lot of photos in the water, in sunny conditions with the camera angled downwards to the water. I rarely use wide angle for my purposes on this particular occasion, it's usually between 40mm and 70mm. The lens hood that came with my lens is a tad too compact, and I find it challenging to put the cap back on after I remove it. I realised that the quickest way to get it back on is to take the lens hood off and put the cap back on, then snap the lens hood back on (then back into my camera bag until my next subject). I'm already putting my camera at some risk when I trudge through water with it for hours, so I soon gave up on the lens hood juggling after a few attempts and shot without it for the rest of the day.
Your thoughts? Thanks in advance.