They are furtives and fast !! I can we took them?

With daylight, it’s almost impossible... But when it’s getting dark, we can try !!
- A tripod
- A long exposure, f between 6-8
and
- to resign oneself to one’s fate !

You need to wait for a flash of lightning during the exposure. So, you will have a lot of "waste"! With a numeric camera, it’s not a problem !
I’m not opening too much because dim flash could not be on the shot.

Here, it was a dry storm, no umbrella!! ;)

Some examples

Those two shots were taken with two different lens: First one with a nikkor 18-200 mm VR, the other one with a macro nikkor 60 mm.
I changed ISO in order to have a longer time to expose, and the opening to let dim light enter in the camera.

JPEG
Opening : f/5.6
Iso: 320
focal length : 67 mm
Exposure 13 s
Date and time : 19 Aout, 20h20

JPEG
Opening : f/4.5
Iso: 250
focal length : 60 mm
Exposure 25s
Date and time : 19 Aout, 20h37

The second sky is more red than in the first shot because sunset was progressing and time exposure was longer.

Flash of lightning, in the second one shot, has been in all clouds but the only part on the shot is on the right, where flash intensity was greater.