A common mistake people make when shooting lightning, is exposing for the scene they are shooting instead of exposing for the lightning shot. Shooting lightning has a LOT in common with flash photography, where the majority of the light in your photo will be coming from the strike itself and not from any ambient light sources. You will want to set an exposure time for between 20 and 30 seconds where a normal shot without lightning will be totally black. The settings I find that usually work for me are around F/7 ISO 100 and 30s for lighting that is very powerful and very close, down to about f/5 ISO 100 and 30s for lighting that is a bit farther off in the distance. You will need to take a few test shots to really dial in the right settings. All of the photos shown in this tutorial were taken at around F/7 ISO 100 30s so this is really a great starting point
One of the projects I have always wanted to do but have not had the time or the weather. Not many lightning storms in Portland.