The blue tit box is about 10ft (3m) above the ground and faces East. The interior floor area is 4in x 3in and about 6in below the entrance, which has a diameter of 1.25in(32mm).
The back of the box consists of a glass panel which can be slid to either side. This allows for easy access to the interior and also means that the glass can be replaced for cleaning without opening up the back of the box at all. Cleaning of the glass is essential before any photography is attempted.
The picture shows the screened area behind the glass and the cctv camera. In the top-right of the picture is a long aluminium arm with a high intensity Infra-Red source.
Above the glass panel you can see a 12volt lamp set into a semicircular diffuser. This is connected to its supply through a variable resistor to limit its intensity. It is adjusted when outside lighting conditions (sunshine) is too bright and causes deep shadows that the IR light source cannot illuminate. Ideally I would like to use an electronic sensor to do this , but I haven't got round to sorting that out yet!
This area is normally hidden behind a black curtain with small viewing openings (with flaps).
