I’ve been fortunate enough to capture quite a few half decent shots of lightning and I’ve found a method that works for me, although it is a stab in the dark most times (ho-hum). I don’t know if the EXIF meta data from the attached shot has survived the resizing, cropping, etc. but this shot was set up like this, and it was a single exposure with no stacking layers in Photoshop:

18mm, manual focus set to infinity, camera mounted on a tripod
Manual exposure: f/5.6 at 12seconds (in BULB mode on my Canon 400D)
100 ISO

During a storm, I’ve noticed that lightning strikes can be quite regular-ish so I basically wait till I think there might be a strike and just open the shutter (using a remote shutter release cable to avoid camera shake), and leave it till shortly after a strike. If it gets to more than about 20-30 seconds I just abandon the shot and try again. I keep repeating that, occasionally moving the camera if the storm seems to move elsewhere. I usually get at least one or two good shots.

I’ve found that using a wider aperture, I don’t have to have the shutter open as long so the images are less prone to washing out. Also, since you can’t really see much of the scene anyway, because it’s dark, I’m not bothered about foreground and background being pin sharp, like if it were a landscape shot during the day. Setting the focus to infinity seems to keep the lightning pretty sharp so I’ve kept to that technique. The other thing that could contribute to non-washed out shots is that I live in the countryside and there are very few distracting lights around, so (cough cough), this might not work in bright surroundings, I’ve not tried it

I hope that helps.

(:

My ISO is already on 100 and my aperture is f/11