If you don't mount the board in the original housing you can reduce the distance from the lens to the sensor. Do a search on MS20 sensitivity. I posted some experiments some time ago. About 1" from the board to the lens does the trick for me. I get about 35 to 45 feet depending on the size on the target and the speed it's moving. If it's varmits that are bothering you, try taping off the bottom portion.