The other day I was experimenting with a series of portraits using my Canon EOS 5D, a 50mm f/1.4 lens, and two 580EX II speedlights (one on camera and one off-camera), triggered with PocketWizard II plus transceivers. In order to be able to focus in the dark I attached a 580EX speedlite on my camera so I could take advantage of the infrared focusing capability of the flash. I didn't want to light my subject with on camera flash, so I first attached a Pocket Wizard FlexTT5 and then mounted the speedlite on top of that. I also attached a sto-fen filter to the speedlite that was on camera and covered it with black photo tape. I turned the power on the flash all the way down to 1/128th power since I was only using that speedlite for it's infrared focusing feature. I then attached a PocketWizard II Plus to the head of the on camera flash (using a velcro strap) and plugged it into the FlexTT5 using a Paramount sync cable. I then set up another speedlite on a light stand hooked up to another PocketWizard along with a small white umbrella. I set that speedlite to 1/128th power and started to shoot. Since my subject (my son) was playing with a LED flashlight, I wanted to catch the trail of the light by dragging the shutter at 0.6 of a second, while shooting the lens wide open at f/1.4. I was able to focus quickly in complete darkness while triggering the off camera strobe with the PocketWizards. All and all I was rather happy with the results and hope to use this technique again.