I took a trip over to Arizona earlier this year to capture the majesty of severe lightning storms during the monsoon. This is a daytime strike taken near the border with New Mexico in a town called San Simon. Daytime lightning is a bit harder to get than night time due to the requirements of longish exposure while there is a lot of light. Also due to the timing required in order to catch the strike.
Due to the way a lightning strike works an exposure time of 1/4 to 1/3 of a second is required. In summary, a strike begins with ‘stepped leaders’ looking for a path to ground. Once this is found, the main discharge takes place in stages. All this takes up to 300 milliseconds. If your shutter speed is faster than this, you won’t catch the whole discharge and the strike will look incomplete. The challenge is to get the shutter open as soon as the strike begins.
I use a variable ND filter to control the light levels.
My setup is as follows:
Set the camera to ISO 100, F11 1/3 second. I then set the variable ND to it’s lightest setting (which is about 2 stops darker than no filter). Setup the scene required, focus on the subject and then adjust the ND filter until the internal meter shows that the exposure is correct.
At this point the camera will get the shot as long as it is triggered at the right time. You can use a wired remote and try to do it manually. I have managed to get strikes like this in the past but it is not at all easy. I use a “Lightning Trigger” (http://www.lightningtrigger.com/). It sits in the hotshoe and plugs into the cameras remote port. It ‘sees’ the light level change with the start of the strike and trips the shutter . Reaction time is about 5 micro seconds so very quick indeed. The camera then opens the shutter but there is a delay in doing this of about 60 milliseconds (this varies from camera to camera). This still leaves about 240 milliseconds of the strike to be captured. It will capture about 50% of the strikes. I have found the cheaper triggers sold on eBay to have a lower success rate.
Once that is set you can stand back and enjoy the storm while the trigger does the work.
The hairs that accompany the main strike are there only for the very start of the strike so often do not appear in daytime shots. In the image above you can see quite a few hairs on the right hand one. This was due to the trigger being activated by the left hand strike but then the right hand one following almost immediately and so, the hairs were caught. Pure luck.
A tripod is essential and you may need some weight attached to it as it is often windy around the storms.
Kit: Canon EOS 7D EF 15-85 ISO 100 1/3 second @ F/11
More of my photos can be seen at FLICKR.