New Canon DSLR user. Flash query...

[Ex Nikon]

Last week I made the big switch from Nikon to Canon! I’ve been so impressed with my G3 over the past year that I decided to go with Canon as my first DSLR. So I purchased the 300D.
However, I must admit I am a little disappointed and confused with the Canon flash system.

I use the 420EX flash with both the G3 and 300D

Firstly, I was amazed that Av mode defaults to slow flash sync! On my G3 and Nikon SLR cameras I’ve always used AV with flash at shutter speed of 1/60 or faster.

In TV mode the flash is still trying to expose the background, so I end up with a large aperture or I have to increase the ISO.

In P mode I have no control over aperture or shutter speed with flash, and in manual I can’t use evaluative metering!

I am trying manual, with FEL, but my images are still underexposed.

I’ve read some threads and articles on EOS flash systems, but I’m still confused!!

What settings and techniques do you guys use to take a normal, indoor flash shot?

HELP!

[Tom W]

Welcome to the Canon side!

Canon's E-TTL flash system has a tendency to be a little complicated at first.

There's a very good explanation out there somewhere on photo.net, but the URL escapes me. Someone else here will hopefully chime in with it.

Anyway, a few of the basics as I understand them:

In Av mode, you set the aperture, and the camera will set the shutter to give a good exposure of the overall scene (depending on the exposure mode you have chosen), but without consideration of the flash. So, if you are in a moderately dark environment and you set it at, say, f/8 to increase your DOF, you'll end up with a shutter speed that would give you adequate exposure without the flash. If it's dark, that will probably be a slow shutter speed. The flash then operates as a fill-flash in this situation.

Conversely, in Tv mode, you can set a shutter speed and the camera will automatically set the aperture to give good exposure, again without consideration of the flash. This means that in lower light situations, the camera will seek a wider aperture.

This means that Manual mode is the best choice when wanting to have a fast shutter and deeper DOF. The flash exposes separately from the camera so that even if the camera indicates underexposure while in manual, the 420EX will still flash to expose the primary subject properly.

One more consideration is that the E-TTL flash system will bias its flash exposure to the active focus point, wherever it appears in the picture. So, if you prefocus, and then change your composition while holding the shutter button down halfway to hold focus, the E-TTL will follow the focus point even if it isn't pointed at your desired subject. If your subject is backlit and you happen to move the active focus point over the bright background, the flash will fire based on that bright background rather than the less-lit foreground subject that you used for prefocus.

BTW, program (P) mode is pretty easy to work with, but you'll probably see 1/60 sec exposure most of the time, and a fairly wide aperture.

[drisley]

I had the same/problem when I switched from my G3 to the Rebel.

Apparently, this is how SLR's function (canon anyway).
THe camera meters the scene as if there was no flash at all.
Then, the flash is used as a fill flash.

If you want to use it more like your G3, or other p&s cameras, set it to manual, set the exposure time to 1/60 -1/200 second, and adjust your f-stop to what you would like for dof. It works really well! Use Tom's info to help you decide your shutter speed, etc.
I find the results much nicer than with the G3 and 420ex.

Good luck!

[defordphoto]

Here's a little morsel to digest regarding flash photography with Canon cameras:

http://photonotes.org/articles/eos-flash/

[Tom W]

Here's a little morsel to digest regarding flash photography with Canon cameras:

http://photonotes.org/articles/eos-flash/

That's the one I was thinking of, Jim. Thanks!

I've bookmarked it on the laptop now. :)

[MediaMagic]

Here's a little morsel to digest regarding flash photography with Canon cameras:

http://photonotes.org/articles/eos-flash/

Fabulous link! thanks!

[nosquare2003]

Welcome to the switch!

Please read the link in RFMSports first.

[DAMphyne]

Does the 300D have a custom function that will allow you to set the shutter speed?
With the 10D, you can pre-set the shutter to 1/200sec, which gives the flash a more typical response.
I've got a 420ex, and upgraded to a 550ex, because the 420 doesn't have full manual control, big surprise to me.

[drisley]

Yes, you can use full manual control on the 300d.

Yes, I find setting the shutter/aperture manually gives the best results for flash, unless I want fill flash.

Curious, do only Canon SLR's behave this way (ie, default to slow sync)?

[Ex Nikon]

:) Thanks for all the advice, guys! I'll stick with manual for flash. BTW, The 300D's autofocus speed is amazing!

[drisley]

:) Thanks for all the advice, guys! I'll stick with manual for flash. BTW, The 300D's autofocus speed is amazing!

Yes, it is fast. And SO much better in low light than the G3.
When you add the fact that it can use the 420ex focus assist lamp (which the G3 could not), it's even more amazing.