Drawing from a photo is art or not?

I'm confused... Should i use my imagination or draw from live objects? People say that drawing from a photo is not art, but only a technique study, They say art should not be perfect... And now i feel like cheating, all that greyscaled photos, grids, zoomed in details, but evrybody does the same thing... And some people cant draw... I do this as an hobby, but still, i spend hours on it so, I really want to know what you guys think...
When I'm satisfied with my technique, should i draw from imagination to be called doing art? Or what?! What's art?
When I'm satisfied with my technique, should i draw from imagination to be called doing art? Or what?! What's art?