|This is Kari Ann, greetings from the Critique Club:
composition: the skull is placed very well in the frame, right along the intersection of the rule of thirds, making my eye go there first, then take in the background.
color: the absence of color throughout the frame works so well for the theme. almost like I am in the desert with sand up my nose.
contrast: great contrast, its so stark, yet, adds so much to the overall theme.
focus: spot on! i love detail, and here i can almost reach out and touch that skull and feel its dry death.
depth of field: again, great use of a shallow DOF.
lighting: making the lighting a lot harsher than it was, was a brilliant idea. The whole scene just evokes desert, from the sand to the skulls to the lighting, its all there and its all being felt.
other: I love this shot. Some may say that this is more about a skull than sand, but, in my eyes, the challenges are not about just using the theme as the main subject, but to use the theme helping another subject. I wish this would have scored higher, as Its a beautiful shot. Keep up the awesome work, i look forward to critiquing more of it. If you have any more questions, feel free to PM me.