Hi Mike Wilhelm,
Great thanks for your reply.
I understand that i got some exposure problems. I get some trouble to adjust my shutter speed, and my frame rate.
I just watch some tutorials, and i think that my next test will be better.
The problem is increase by my post treatment with Premiere Pro.
About the D7100, the only problem is that you can't switch your aperture in Live View.
I think that i will be restricted by my lense ( 18-105 / 3.5-5.6 ), but my first step is to be at ease with it.
Thanks god, that my wife is a wedding phtographer ( WPJA ), and she give me some advices.
And i like people like you, who give me some too.
If you have something else important to notice on it, just tell me.