Lens Hood Questions

[Groucho]

sometimes i use them sometimes i don't. now that i have some better low light lenses and more noiseless iso i'm trying to get back in the habit. before sometimes they cut out to much light so i was constantly putting on taking off anytime i walked under shade or something which was very annoying so often it was easier to leave them in the bag.

The lens hood should not affect the exposure of a scene in any way - it's not like you're forced to bump up the ISO when you mount a hood. It should make zero difference except for reducing flare from stray light, not the light that comes into the lens. (The coatings take care of those.)

 

[jann1033]

The lens hood should not affect the exposure of a scene in any way - it's not like you're forced to bump up the ISO when you mount a hood. It should make zero difference except for reducing flare from stray light, not the light that comes into the lens. (The coatings take care of those.)

you'd think so but if i was under somewhat dense shade with my 70-200 f4 lens I'd usually have to take off the hood to get a high enough shutter speed. I knew it was the hood since as soon as i took it off i could get the shutter speed i needed ( championship deductive reasoning on my part there) that was with my xt. i haven't been in that situation with my 40d yet so i'll have to see if that is the case with that camera. the hood for that lens is a round rather than petal hood which i thought must be the problem since most of my other hoods are petal hoods. it was annoying at any rate.

 

[MICKEY88]

you'd think so but if i was under somewhat dense shade with my 70-200 f4 lens I'd usually have to take off the hood to get a high enough shutter speed. I knew it was the hood since as soon as i took it off i could get the shutter speed i needed ( championship deductive reasoning on my part there) that was with my xt. i haven't been in that situation with my 40d yet so i'll have to see if that is the case with that camera. the hood for that lens is a round rather than petal hood which i thought must be the problem since most of my other hoods are petal hoods. it was annoying at any rate.

I'm with Groucho on this one,,, my 80-200 has a round hood and I've never notced it having an effect onexposure..you're metering off of the subject area, not the lens front element surface

I think the clouds moved while you were removing your hood....