Multi LEDs wall in Maya/Mental ray

[sand1]

Hi,

I am trying to create a multiple leds wall like in this image:
http://imworld.aufeminin.com/story/20150126/mascara-volume-effet-faux-cils-formule-perfectionnee-yves-saint-laurent-32-580671\_w1020h450c1cx508cy248.jpg.
I have tried with multiple point lights (approximatly 900 as in this photo) but:
- either black wall becomes white because of big number of lights,
- either, when I lower intensity of each of it, result is a grey wall with too soften lights.

Is there a specific technic to make this effect?

Other question: is it possible to make an only attribute editor for multiple lights? Exemple: modifying intensity from 1 to 2 for all my lights in a general "pointLightShape".

Thanks in advance