If you listen to folks on Facebook, you might think that lens hoods are designed as some form of mystical lens protection. They’re often touted as the alternative to UV filters as a way to defend your lens against the evils of the world that might otherwise turn it to glass dust.
But, no, their primary function is actually to flag stray light from entering into your lens and causing flare. In this video from Adorama TV, photographer David Bergman talks about lens hoods, when you might want to use one and when you might not.
As mentioned, light sources hitting the front of the lens can cause flare. Even if they’re not in the shot, they can hit that front element, bounce around inside, and then you get those bright spots. It can even wash out your entire image and reduce contrast. Great if you want to use it for creative purposes, and by all means discard the hood in those instances. But otherwise, it’s best to keep it on and avoid the flare.
Do note, though, that when the light source is directly in the shot, as it is in the image at the very top of this post, a hood isn’t going to help you. There’s no point having lens hoods that actually appear in the shot. And if the hood isn’t in the shot it’s not going to block the light. So, you get flaring. Hoods are to prevent flare from lights hitting your lens element from outside of the frame.
Ok, yes, lens hoods may help also a little with protection from scratches, and it’s rarely a bad idea to keep one on your lens, unless you have a reason to take it off. But, they’re not going to prevent your lens from being destroyed. And it’s never been a thought I’ve entertained when choosing when to use or not use one.
For me, it’s always about flare control and preventing flare from happening. But, if it makes you feel better, sure, your lens will become invincible.