Light period and optimum growth/production during flowering

Considering:
Some Indica varieties require as little as 8 hours of dark to begin flowering.

Wondering if there are differing opinions on the number of hours of light/dark for optimum growth/production during flowering. Did a search with no luck - any suggestions?

Has anyone found a light period of greater than 12 hours to be optimum for production during flowering?
If so, the variety and Indica/Sativa or ratio.

The other side of my brain is wondering if anyone prefers less than 12 hours?

It isn't fun. If anyone would have found something better than 12/12 we would know about it and would all be doing it.