Flowers and Tree by XFrog
(http://www.rendus3d.com/data/501/Tournesols_2ter.jpg)
The trees and sky are perfect and really good lighting. The sunflowers appear synthetic and, if this is only one render, the horizon seems to have cutoff the tops of the sunflowers. Or, did it?
yes there seems to be something un-natural about this image....there is a sharp line between the background and the middleground....
is the background an image map projected thru camera??....
The background isn't a image !
Hmm... again your use of models is great, and as calico said your lighting and clouds are brilliant, but that big sharp line is ruining it...
the only thing except an image map that could cause this (as far as I know) is if you've left the terrain flat, if you did do this I recommend you put in at least some small displacements to get rid of the line and make it seem more natural.
yeah, that straight line of sunflowers spoils this image.