adammazza wrote in post #2461863
Thanks, this seems to be working well for me.
Switching to manual with 1:1 definately seems to be too powerfull for what I've been shooting.
Is there anyway to tell what the flash is actually firing when it fires in ETTL II mode? I'm not seeing it in any exif data?
As a side note, I was pleasantly surprised to see that I can shoot at 10mm with no vingetting with the 580 and wide angle screen. I guess in the manual when it says 14mm they are referring to 14mm on a FF camera.
thanks
Adam
The good thing with setting the flash to manual mode is that you can control exactly how much power it is going to output (within the constraints of the flash itself, of course). If 1/1 is too strong for your needs, you have several options available to fix that. You can use any one of these options or a combination of options.
Option #1 is to decrease the power output, like to 1/2, 1/4, etc. depending on how strong 1/1 is. If you have the flash head pointed straight ahead, you can use the distance scale on the back of the flash to tell you what output you should set the flash to. For any given power output, aperture, ISO and flash zoom position combination, there will only be one distance that will be optimally lit by the flash. And that is the distance that is displayed on the distance scale. If the distance you see on the distance scale is farther than the actual distance of your subject, you will need to decrease the power output some more. Keep checking the distance scale as you decrease the output and stop when the distance shown on the distance scale is very close to your flash to subject distance. It doesn't have to be dead on. Close enough is fine. BTW, the camera has a tendency to go to sleep mode so you will need to half-press the shutter button every once in a while to keep the camera awake and talking to the flash. The flash needs to know from the camera what the aperture and ISO are set to so that it can calculate the distance.
Option #2 is to adjust the aperture. If 1/1 is too strong, you can decrease the aperture while checking the distance scale on the flash, the same way it was done with Option #1. When the distance on the scale matches your flash to subject distance, the aperture has been set to properly expose the subject.
Option #3 is to adjust your flash to subject distance, if possible. The farther the subject, the more flash power you will need. And the closer the subject, the less you will need.
Option #4 is to adjust the ISO. .
These options assumes that you are using direct flash. If you are going to use bounce lighting, then you will need to take the flash to bounce surface to subject distance into account as well as the 1 to 2 stops loss of light from bouncing. It's not an exact science when using bounce but with practice, you'll be able to get close enough to only require a little tweaking after chimping the LCD screen.
It may not always be practical to shoot with the flash in manual mode, but it doesn't hurt to learn how to use it and give it a try just in case. You never know when it could come in handy. 
