Thank you, guys, for commenting!
The cloud was indeed cooperative and generous enough to show variations of lightning, so long as it was far enough.
Tom, I wish you to succeed to capture the lit mosque and show some results here!
I love those forked lightnings, pity it is a grab from movie.
In the absence of a lightning trigger, next time you could try the following (it worked for me in a much less spectacular settings):
Base ISO
As high f/number as you dare (think diffraction)
As long time as you can.
You can also add a ND to further increase exposure time (I don't like ND's, they are seldom truly neutral in cast)
Put it on an intervalometer or something similar and let it go.
You will have a lot of useless shots, but you can delete those, and occasionally a good one - shot at base ISO so you have the widest latitude for post-processing
Simone, thank you for the advice. I would have liked to try the method, if I was planning to shoot the lightnings right from the beginning.
One problem of this method would be the hot pixels caused by the long exposure in the crazily hot Tokyo (even at night). If the noise reduction is activated, you can shoot much less frames than without the noise reduction. Maybe the pixels could be easily corrected, because I would not be shooting star field images.
Armando, I found a dedicated trigger for the lightnings:
http://mkcontrols.com/lightningbug/Its concept based on the scientific research of the thunder is worth reading.
