Listen up check it out if you need with other info sites here's my experience and i've grown dozens of autos in and out. Don't use 12/12 use 18/6 don't worry what your plants need is to have strong light on them at least 15+hrs direct sunlight and the temps need to be above 75f move them if it gets above 95f to shade. They will slow down in cold and above normal temps.
I haven't grown them in a couple of years but I've grow plenty. Working on a Magnum auto x reg Dragon cross (accidental cross someone did) that I've gotten 90% autos and I then I accidentally crossed with GDP (grew autos in the garden and a GDP female popped in a tomato start) which has produced an auto GDP at F2
Much more work to stabilize the line but the basics are done and I even kept seeds from F1 to cross back. The regs that grew out of the F1 group were special. Dragon leaning with some diesel.
Also this one Magnum
Smelled like dirty dish rag, fell in fricking LOVE with that smoke. It
Hermed and produced 27 seeds and not one of the dozen I've grown since produced that smell although they've all looked
Lost but I'll never forget it.
So anyway Prop, get those babies in the sun but let them adjust slowly. First day put them in a shady spot. Second day in a simi-shady spot, and then maybe 1/4 day in sun, etc. Work it slow if all it's had is artificial light. The sun is powerful and can burn plants so go slow.
Also you can give your plants both sun and artificial keeping 18+ hrs of light.
You can do 12/12 but 18 is about optimal