580 EX II Pre-Flash?

[michael_wilson9]

Recently purchased the 580 EX II for my 40 D.

I am curious to find out if I will be able to tell if the camera pre-fires in ETTL II mode.

I do not see it at all. I have even held the camera away from myself to see if it double fires.

I have the camera set to ETTL II mode as well as the flash.

 

Do I have to set something else where or am I just not able to see the pre-flash?

 

thanks in advance.

Mike

[cabbiinc]

Press the * button, if it flashes its preflashing. If not, then you need to do something different. Possibly a slight twist in the hotshoe.

[mark u]

Dan's trick works so long as you don't have the * button set to handle AFstart via custom functions. Reset the custom function if necessary to do the test. Another method is to use second curtain sync with a longish shutter speed - e.g. 1/4 sec. That will separate the flashes sufficiently to see them both.

[ross_holmberg]

don't hold the camera away from yourself... instead take a shot as normal, looking through the viewfinder. You'll see a flash

through the viewfinder, that's a pre-flash... the actual "exposure" flash happens when the mirror is up, so you can't see that

one through the viewfinder.

[michael_wilson9]

Both methods worked great thanks.

Really saw the difference with 2nd curtain sync.

 

thanks

Mike

[JosvanEekelen]

Another way of checking the preflash is setting a long shutter speed and 2nd curtain flash. In that way you see the

preflash after you pressed the shutter button and the main flash when the shutter closes

[jay a. frew]

Hello Michael:

 

I am curious about why you want to see the pre-flash. If your flash is giving you good, consistent results in

ETTL mode, then, the pre-flash must be happening.

 

I have seen pre-flash through the viewfinder (as mentioned above) under certain conditions (of which I cannot

recall). At first, it unnerved me a bit because I couldn't figure-out why I was seeing flash before the mirror

went up.

 

I get a pre-flash when I press FEL. It is quite easy to see it because is doesn't happen the instant before the

main flash. I am just not sure if the FEL pre-flash is the same intensity as the "regular" pre-flash. But, if

you want to see a pre-flash, press FEL (pg 102 in the 40D manual).

 

Cheers! Jay