We have a wireless camera that we purchased rom Walmart.
Our barn is almast 300 feet from our house and it has wood sides and a metal roof. We had to place the reciever near a window in our house since we have a brick home. But it worked for our 3 babies last year. We did not miss a birth due to this camera. Infact we went and bought a 2nd camera for my mother inlaw to be able to watch from her house.