How to get the most out of 2 x 550EX? Advice please.

[oistein]

Hi,

 

I've got a couple of 550EXs to use with my 1V and 10D cameras. I am

wondering if I should purchase a handheld lightmeter (e.g. Sekonic L-

558) or if I should trust the E-TTL. I like to have control over the

camera and I feel that the flash output in E-TTL mode is somewhat

unpredictable. What about using a gray card?

 

I am also wondering how I can use the 550EXs in such a setup. I was

thinking of using omnibounce to spread the light from the fill flash

a little. Any thoughts? Any recommendations? I am going to use these

flashes for portraits both in- and outdoor.

 

Thanks in advance for a reply!

Oistein.

[will_perlis]

Check out Neil Turner's articles on dpreview.com, including this one:

 

http://www.dpreview.com/learn/Lighting/Using_two_550EX_01.htm

 

With a 10D you can see the results as you tinker tho' a meter will save time.

[jimstrutz]

The problem of using a meter with a 550EX is that in E-TTL mode, the pre-flash will fool the meter. If you're close the pre-flash will actually be brighter than the real flash. That'll mess it up for sure. The fix is to use the 550EXs as manual flash units. Then the hand held meter will be fine.

 

I find wireless E-TTL to be accurate enough, but I'm using negative film. A DLSR is more like using slide film, where exposure accuracy is more critical. Also, with E-TTL, the camera is highly sensitive to where the active AF point is. Focus on the wrong spot & exposures will be off. Same thing if you focus & recompose, if you don't use FEL. Still, I use manual flash most of the time that the pictures are critical.

 

I fire them into umbrellas. The light is them coming from a larger scource & the shadow lines are softer. The only way an Omnibounce will help significantly is if you are in a small room. Then the reflections can fill in a bit of the shadow areas. Otherwise get a large reflector or an umbrella.

[oistein]

Thanks for your suggestions!

 

I think using the 550's in manual mode and measuring the light with a handheld meter sounds like the safest way to go.

 

However, if I have one flash 90 degrees on the model and the other flash on camera - how do you place the incident meter to determine the output from EACH flash (should the "ball" face the on-camera flash, the other flash, or between them ..or?)?

 

Do you have to do a test flash from EACH flash, then meter, then select the flash output? Or can I fire both flashes at the same time, do a reading on the incident meter, and then determine the flash output from each flash?

Sorry, I'm just used with daylight photography...

 

Thanks for any input!

 

Oistein.

[jimstrutz]

Well, if I were you, I'd try Canon's wireless E-TTL metering to see how well it works for you. It's simpler, and with the 10D you can tell right away.

 

When using manual flash, I start out by pointing the meter at the key light (usually the one from the side) & shield it from the fill light. I *manually* fire the flash & take a reading. Then I do the same for the fill light, compare the apertures reported by the meter and adjust the fill light to be a stop or two dimmer.

 

Then I take another reading, while firing both flashes and the meter pinting at the camera. This is the aperture I use for the camera.

 

The problem with this is, using Canon's wireless system in manual mode, the flash units still fire communication pre-flashes. Your meter is very likely to give wrong readings with those. That's why I recommend firing each flash unit separately & manually by pressing the open flash button on the flash while metering. You will either have to have someone else fire the flash or mount the meter on a stand.

 

This won't work for the final measurement though, since firing both flashes will probably require you to use the wireless communication with it's pre-flashes. What I do is simply use the aperture reported by the key light metering. This might be slightly overexposed, but that's not a bad thing with color negative film. With the 10D you can tell right away.

[gene_austin]

As a followup question, I see that Sekonic is offering a wireless transmitter module

for only $25 when you buy their L-358 meter. Is it possible to get the meter to

trigger the 10-D? If so, other than a Pocket Wizard receiver, what other cables are

required and how much would they cost?

 

The reason I'm considering such a setup is that I also have a Mamiya 645E MF rig. I

presently own a 550ex and a 420ex. Should I just get a ST-E2 and use the 10D as a

light meter for the Mamiya? If so, will the lack of manual control on the 420ex

present a problem?