580 ex II Flash missing 1 in 3 shots

[RoryOD]

I hope someone might be able to help me out.

When i am shooting bounce flash (580 mk II on ETTL with cp-e3 & 12 fresh batts) with my 40d (iso250) and drive sent to H the flash will fire for the first 2 shots but miss the 3rd - thus causing a long expusure and delaying or missing the shot i want/need. :o

Its only for press jobs i might only do about 4 times a month. but it still bugs me.

I swapped my kit on to another togs 1D mkIIn and the same thing happens, he then asked what i was trying to do and i found out that he has the same problem.


How do i solve this, settings? i know that when using bounce the flash needs alot more power to light the scene so do i need a quantium pack or more power etc.?

thanks guys.

[40Dude6aedyk]

Couple of things you can do:
1. Have you set the Quickflash mode, CFn06-1 (p. 10 and p. 27 of the manual.
2. Do you have a fast CF card?

[JeffreyG]

You need more power I guess.

It never really occured to me to even try to use a flash in a burst mode. I'm honestly suprised that it is getting off two shots bounced before it is off recycling.

[RoryOD]

Couple of things you can do:
1. Have you set the Quickflash mode, CFn06-1 (p. 10 and p. 27 of the manual.


i dont have the manuals, they are about 40 miles away in a loft... any chance you could break down those steps. thanks

[RoryOD]

on and using a 4gb sandisk extreme IV or a 4gb UDMA both at 300x i think and using jpeg.

[40Dude6aedyk]

Breakdown: Attach flash to your camera. Turn on camera. Turn on flash. Press "Menu" button on your 40D. Find the "Flash control" menu. Then "External flash C.Fn setting", set number 6 to 1:Enabled.

I think the other photog didn't do you any favors. When you get closer to the manual, you should probably read it cover-to-cover and try every setting to understand it. In my real job I help edit and write manuals, so that's my perspective.

Since I think many shots use less than 1/8th the capacitor charge, you should be able to get off a burst of 6 to 8 shots easy provided you don't make the flash wait until it is fully recharged.

[RoryOD]

THANK YOU... just tried that and its perfect. i only need short burst like 5-8 in a row.
Is there and fear of frying my flash doing this!, or is it comon sense like after 10 shots in a row give it 5 seconds rest?

Thanks you again 40Dude & Happy Christmas

[RoryOD]

ok downloaded the pdf manual for the flast and it says after 20 let it rest for like 8 seconds. just found out that it has a modelling light too!!! ok looks like the manual is going to be me christmas book to read.

thanks all

[40Dude6aedyk]

Man, you are gonna have to read your manual where it talks about frying your flash. ;)

The reality is that you cannot get a burst of 5-8 flashes at 1/1 in a row. I will assert without proof that single burst of 1/1 releases as much heat/power as about 4 bursts of 1/8. Remember the flash is recharging while firing and most of the power is in the first 1/2000th of second of the flash duration.

But why not try this experiment: Set flash to manual mode at 1/16 and burst until it stops. Then try again at 1/1. Let me know in the next 5 minutes what happens.

[RoryOD]

im getting 7-8 shots on M at 1/16 and the same on auto/ettl but only 1shot on M at 1/1

[DDCSD]

Get a cp-e4 if you want to shoot bursts.

Be careful not to fry your flash.

[40Dude6aedyk]

im getting 7-8 shots on M at 1/16 and the same on auto/ettl but only 1shot on M at 1/1
Thanks for doing the experiment. I hope you have a feel now for how the capacitor in the speedlite holds a charge that can be divided up into one or more flash pulses.

So in a situation where you need a lot of light from the flash, you ain't gonna get 7-8 shots. But also a burst of 7-8 flashes at low duration/power is not gonna fry your flash either.

[gambit]

I had the same problem until i just realised tha batteries were flat !