Canon 30D Funky Flash Metering in Av

[TheChadVIII]

Howdy! I have a question for ya'll Canonites.

I have a 30D with a 430EX on it, and I like to think I'm rather familiar with it.

Just recently, when the flash is turned on with the camera set in in Av mode with the custom fuction for it being Auto too, the camera meters exactly as it would with the flash off.
So in low light with flash on I'm getting shutters of 1second+ as if there was no flash.
Flash is on (properly too) and will fire causing very weird motion blur and overexposure.

Setting the custom function for Av flash to 1/250th will fix it but totally ruins the range I can take pictures with the flash that would have benefited from a slightly slower shutter, since a 70-200 is my walkaround.

In P the shutter won't go below 1/60th with the flash on, and the same goes for Auto. So any ideas why its being goofy in Av mode?

[tragic hero]

send it to canon?

[TheChadVIII]

Maybe I'll just use P mode until I need to get it cleaned and make them fix it if its not just some weird setting on the flash or something that I have messed up.

[tommas4]

This should help. Copied from article linked below.
P (program) mode keeps the shutter speed between 1/60 sec and the maximum flash sync speed your camera can handle. It does this so that you shouldn’t need a tripod, even if light levels are low. It then tries to illuminate the foreground using flash.

Av (aperture priority) and Tv (shutter speed priority) modes set the shutter speed or aperture to expose for the existing light conditions correctly. They then fill in the foreground using flash. If light levels are low you will need a tripod to avoid blur.

M (manual exposure) mode lets you set both aperture and shutter speed to be whatever you want. The camera then automatically controls the illumination of the foreground subject using flash.

I reccomend that you take a look at whole article here, as Canon refuses to make it easy to understand from start.
Tomas

[TheChadVIII]

Ok! You're right! It even does it with the built-in flash too.

I haven't done any real flash photography in a /long/ time and must've just had a memory lapse on what setting I used it on... and my friend's 20D must've had the 1/250th setting instead of auto in the custom functions. I thought there was something wrong with my settings, haha.

Thanks for clearing it up!

[tommas4]

No problem, I just wonder if Nikon users have to go thru similar trouble before they learn to use their flashes.

Tomas

[engstrom]

Originally Posted by tommas4

No problem, I just wonder if Nikon users have to go thru similar trouble before they learn to use their flashes.

Tomas

From my film days I remember Nikon flash and camera settings being much more intuitive. When I first got my Canon flash I found the idiosynchrisies of the flash with program settings (P/Av/Tv) to be quite annoying and interfere with my picture taking. Now, however, after 2 years of using it I find it quite natural. All I use for flash photography is Manual mode on the camera and I have developed a real good feel for ambient light levels/shutter speed/aperture/ISO/flash exposure. My suggestion is to use Manual mode only for flash and start paying attention to ambient light levels and setting shutter speed/aperture/ISO accordingly. It may seem daunting at first but when you combine it with the histogram of the camera it really doesn't take much time at all to get good at it.