Well anyone with some canon exp please chime in. Chuck??

Here is the gear: 40D, 580 flash, PW’s, 15 foot ettl cord, Sek L358 light meter, light stand and umbrellas.

Here is what I want to do: Take outdoor portrait with pretty blue sky in the background using the flash off camera to light the front of the model.

What I need to know is how I go about metering the correct exposure for the ambient sky and then adj the flash to expose correctly for the model.

I tried to do this with the PW but with a max shutter of 1/250th I end up at F16 or higher and cant seem to get that much juice from the flash to light the model.

I have tried the ETTL cord with the flash set to high speed synch but still cant seem to get what I want.

Anyone using the same or similar equipment have a system down for this?

you'll have to get your flashes really close to the model, so it helps to back up and use a longer lens so you can sneak those flashes in closer.

You can also get a major boost by waiting till a bit before sundown. You'll still get the blue sky you're after, but your flashes won't have to work so hard to get the right exposure

This was with a 580EX and a 430EXII, but you can get the same frontal lighting with 1 flash. The flash was in a Ezybox, so that sapped power further but still the flash had enough to get the right ammount on the subject

K_Strecker gave you some excellent advice and I'll do my best to add some more.

If you've tried HSS then this means you've managed to get the flash with the 15' sync cord and umbrella all close enough to the model without any of it showing up in your frame. That really is most the battle.

I do it w/o a lightmeter as follows.

1. Set the camera to Manual (flash off) and frame the scene as if you had the model in the shot (wether or not the model is there or not). First pick your desired aperature and then move your shutter speed until the cameras meter tells you that you are properly exposed.

2. Take a shot and check the histo. If you get blinkies or your not all the way to the right then adjust the shutter speed accordingly and chimp until you get no blinkies with the exposure to the right.

3. Then "purposely" underexpose the scene by 1 stop. (This usually means clicking the SS 3 times). This will give you a more saturated sky. Chimp again to see how the background looks on the playback. I've dialed in anywhere from 0 to -2 exposure to get a sky how I like using the shutter speed to control the amount of "underexposure".

4. Now turn on the flash and set the FEC (either on the camera or flash) to ZERO. Remember the flash overrides the camera setting, so I always just set it on the flash. This assummes that the flash is connected via your 15' ETTL cord. Make sure the flash is in HSS mode.

5. Put the model in place and chimp off a shot. Adjust your FEC accordingly.

For example, in the excellent example K_Stretcher posted I would try bringing down the FEC - 1/3 just to see what it looked like. He probably tried that and thought this was the best look.

What is nice about using this ETTL method is it allows a bit a movement to your model once you have your settings just right. If the model moves 18" closer or futher, the Canon ETTL is usually very good at adjusting accordingly and the images will be exposed consistently even though the model is moving back and forth for whatever reason. This does not happen in manual.

Your biggest concern is just how much power you have. The canon flash sacrafices a lot of power to use HSS and even without HSS the 580EX can't overpower full sunlight. So it is best to use this technique late in the day, on a overcast day or in the shade of full sunlight. So you may find that the model can not back up at all because the flash is already putting out its maximum amount of power in HSS mode. In this case the model could only move closer to the light to keep consistent exposures.

Good luck.

First of all you can't meter Canon flash with the L-358 if used in ETTL or wireless mode, because the pre-flash skews the reading. I've got a L-358 I use in the studio but I don't use it with the Canon flash.

Its not really complicated and doesn't require a meter. Start with the flash off and use the over exposure warning of the camera to keep all the significant highlights below clipping with just the ambient light. The have your subject hold a white towel next to their face, turn on the flash, and adjust power until the towel is just below clipping in the camera warning.

But realize that flash will only work to reduce the contrast of the scene if you shoot into the shadow of the ambient light. When you put the sun to the back of the subject and use a flash in front it actually performs the role of key light not fill. The fill comes from the sky the person is facing. On a Sunny 16 clear day the shady side of the backlit head (the face) will read 3 steps darker, Shady 5.6. A single flash on a bracket works OK for full face poses, but if you move the flash off axis and rely on just the sky for fill the shadow will be dark and you'll have no control over the lighting ratio. Thus if you move the flash off axis its actually better to use two flashes. The one off camera as the key light creating the highlight pattern, plus one on the bracket over the lens to supplement the - 3 stop fill from the sky. See this thread for a more in-depth discussion of shooting in sunlight with flash: http://www.fredmiranda.com/forum/topic/751937

Outdoors I prefer to use high speed mode with the Canon flash so I have creative control over DOF via aperture. I've written this tutorial which explains how to use it: LINK TO PDF. The drop in power in high speed FP mode needs to be compensated for by using wider aperture. Also since the flash pulses continuously it act like a continuous source and shutter speed will affect exposure.

Chuck