Question, calculating settings for 550ex/420ex portraits

[MediaMagic]

Okay, what I want to try is using the 550ex and 420ex together for a fast portrait setup for times when I'm not able to use the studio strobes for whatever reason. I want to reflect them with umbrellas. My question is, how would I calculate the zoom settings for the flashes? Is it a trial and error thing? Or does it matter when they are reflected? I've only used these in ratio aimed directly at the subject and that is straightfoward and simple. How would being reflected change the approach? Does anyone do something similar?

I understand that I can't use my light meter because of the preflash, but I don't see any reason why it can't be done anyway using the preview and histogram.

Thanks,
David

[DaveG]

When you turn the 550 to Master, the zoom will automatically go to 24 mm. This is to broaden the E-TTL flash pop so that the slaved flashes will see it.

What I'd done is to have the 550 on a bracket above the camera. It's pointed at the subject directly and it will be the fill flash. Then I have a 420 set up and bounced into a small umbrella. This is the main light and is set to one side. I mess with the ratios until I like what I see, (1:3 is usually nice.)

Sometimes though this setup goes E-TTL on me (E-TTL is Canon jargon for "This doesn't work dependably or predictably, but we will pretend it does and the boobs out there will be too stupid to realize that we've conned them, and will blame themselves.") and I can't get enough light from the main. Other times it works just fine. Go figure. And hopefully the guy who invented E-TTL has dies a painful death.

[cowman345]

Quick question - can you use the 550ex with a lightmeter if it's set in manual mode (note: i do realize the 420ex has no manual mode, though).

-dave-

[DaveG]

Quick question - can you use the 550ex with a lightmeter if it's set in manual mode (note: i do realize the 420ex has no manual mode, though).

-dave-

Yes