I’ve been wanting to do the whole multi-pop flash thing for a while now, so with the upcoming MTB world cup I though it would be time to get it sorted. The problem with most multipop exposures is that they all look washed out. There is no MAIN exposure. To get around this I am using 2 fashes – one for the multipop and the other for the main exposure. You do need to have a very dark background like the night sky.

Here’s the idea :
1. Have a guess at the exposure time for the frame. In this case 1/2 a second.
2. Work out how many pops you want in the shot. In this case 4
3. work out the timing for the pops = 8 hz, 4 pops in half a second.
4. Work out the main pop exposure, remembering that shutter speed is not important only aperture.
5. Set the camera for ISO 200, f5.6 0″5 exposure (manual of course)
6. Put a Multimax on the camer hot-shoe. Multimax’s are able to hold the exposure open for the 1/2 second. The PLUSII units only send 1 pulse at the start of the exposure.
7. Connect a PLUSII to the multipop flash and set the 580 for 4 shots at 8hz
8. Connect another Multimax onto the Main flash and set the delay to fire on the 3rd of the multi-pops.
Take a test shot…..

You will see there is ghosting on the 3rd exposure. This is caused by the main and multi not firing together. Hmmmm don’t forget that the PWs have a 0.002 sec transmission delay. Back the delay timer on the main off by 0.002 sec and test again.

NOICE!!!!

SETUP Geeky stuff….
* Exposure Time = .5 Sec
* Flashes per exposure = 4 = 8hz
* Main Flash delay = ((.5 / 4) X2 ) – .002 = 0.248 (NOTE – Delay starts at the first POP so the first shot is 0, then 1, then the main flash on 2 or after 2 delays – Make sense??)
* Main flash exposure = f5.6
* Main flash power = 1/64, Multi is 1 stop down at 1/128th. (This ratio works all the way up to 1/8th power – Multipops abive this are not recommended/possible)

Now I just have to do the same thing with a MTB flying through the air at 60km/h…..Worth a try though!!.