Okay, so I have a bit of a tight budget, so I need to choose between the screw autofocus 50mm f/1.8 and the new 35mm f/1.8 DX. I'm not really in a rush, but the 35mm DX is out of stock at my local shop. But, they do have the 50mm. I do have a D40, so focus will be an issue. Is it worth waiting for the 35mm or just getting the 50mm?