Lens hood producing shadow?

[db83]

I have a Canon 24-105L on a XSi (450D). I'm new to shooting with lens hoods, so I guess the first question is: should I be shooting with the lens hood on when using the flash?
I did that for some shots and noticed a semi-circle of black that comes from the bottom of the picture. Is this normal? Is it possible that my lens hood is damaged (bent) since the camera rests with some weight on the lens hood?

[korman]

This happens on my camera (Olympus in my case) too at the wide angle setting. It just means, the built in flash is mounted too low and doesn't work with the hood. With a proper flash in the hot-shoe,the problem isn't there.

So best just take off the hood when using the pop-up flash in those settings where you get shadows. I doubt there's another solution.

Korman

[db83]

Ok, I was just making sure that it wasn't caused by physical damage to my lens or lens hood.

[Mike_PEAT]

First you didn't say whether you are using the built-in flash, or a flash in a hot shoe.

Second, if there was any damage it would show up in EVERY picture, not just those where you used the flash.

[tfiorda]

This is a common problem with wide angle lenses and hoods when used with pop-up flash and sometimes with accesory flashes that aren't tall enough. The distance between the flash bulb and the hood is too short and the light get blocked by the hood. There are two way around this, first take the hood off when using pop-up flash. Second use a accessory flash. That will extend the distance from the bulb to the hood and in most cases remedies the problem. Sometimes you may need to put the accessory flash on an adapter to further increase the distance.

So there is nothing wrong with the hood or the flash, it's just the basic design that is causing the problem.

[db83]

I was using the pop-up flash. And thank you for the responses. Eases my mind a lot. I will try with my 430 EX.

[moxi1]

Hi there,

A good way to prevent your lens causing a shadow is by using a diffuser on your build-in flash. ( of course you always have to take off your lens-shade for this)

You can make an simple diffuser yourself by using a "milky" clear plastic pill container, or an old film container with a piece cut-out so it fits over the flash.

It works like a dream and gives a softer light.

Cheers Moxi1

[korman]

Originally Posted by moxi1

A good way to prevent your lens causing a shadow is by using a diffuser on your build-in flash.

Hello Moxi,

the proposed solution doesn't really help resolving that problem, because the diffuser doesn't change the angle of the light to allow it getting to the part shadowed by the lens and hood.

hood.jpg

As you can easily see in above picture of a white wall, on my camera at the widest angle of my standard lens (28mm equivalent for full frame), the hood produces quite a pronounced shadow on the bottom. With a diffuser, the result is pretty much the same. Just for fun I tried it without hood and even then the lens produces a shadow for the built in flash, though much less.

The only solution here is not to use the built-in flash on the widest setting, a proper hot-shoe mounted flash is needed. When zooming in, the problem goes away too.

Korman