Needs higher contrast, which can be done in photoshop or the darkroom, whether you'll be able to keep your shadow detail at that level of contrast is another issue, careful exposure is the key. Other possible causes - lens flare, depending on the position of the front element of your lens relative to the sun these reflections can kill almost all the contrast your lens can deliver, its evil stuff. Hoods help tho, heh.
Art ......wonderfull name by the way......the Gary summed this right up....reallt good frame.....light went flat...butyou should be able to either print this up brighter and with more contrast or photoshop the fix..... Welcome to usefilm....(bet you that first name gets you in trouble here)