You can achieve better results if you lower your ISO. You do not need 1600. Go to 200, the minimum with isd D. It is 3 stops down. Keep your F13 for the deapth of field, and change your time by three steps also - to (always devide by 2) 1/125s. You will not have any grain, and your pictures will be better. To eliminate the drastic difference in between the light and shadow, use neutral graduated filter from Cokin (cheepest and good).
This way you will have detail in the shedow area. Of course, use a tripod.
