In this second of three articles on building a bird box with video camera, I’m going to be looking at the various components that you will need. Whilst building the nest box, you need to give some consideration to the camera, wiring and electrics. This can be as simple or as complex as you like. Some nest boxes have a type of modular system, where the camera can easily be removed and placed into another box, increasing your chances of catching something on camera without doubling up on kit. Also, you may wish to consider infrared lighting. Although nice to have so you can see inside the box during darkness, it isn’t really necessary. Most modern cameras have very low light capabilities and can ‘see’ right into dusk as the birds settle for the night. During the night very little, if anything, happens so you won’t be missing much if you decide not to fit infrared lighting.
Here is a list of items you will need:
- A good low light capability board camera. There are two types of sensor, CMOS and CCD but which is best? CMOS use less power and are cheaper but a CCD sensor is best for low light and overall image quality, which is what we want. Number of lines affects image quality too, go for as as many lines as you can afford for improved quality. The lens should be between 3.6 and 4mm in order to get a good view of the bottom of the box, 3.6mm will give a 68 degree angle of view and 4mm will be approximately 62 degrees with a 1/3″ sensor. Try this angle of view calculator for different lens/sensor combinations. A 420 line 1/3″ CCD sensor camera can be found on eBay for around £15, 540 lines for around £25 and 600 lines for around £50. The one I fitted to this box is 540 lines and is is probably the best compromise of performance vs cost. Additionally, you should get the best low light ability you can, down to 0.01 lux if possible.
- An inline microphone as used for adding sound to CCTV, unless this is built in to your camera. This just connects between the camera and your monitor, using the same power supply as the camera. Again, available very cheaply on eBay for less than £10.
- 3 core cable (2 x RCA 1 x power) for power video and audio long enough to reach your PC or TV. This carries composite video (yellow), mono sound (white) and Power (black)
- Optional infrared LED lighting. If you are building your own you will need several infrared LEDs of the right wavelength. Infrard LEDS come in several wavelengths 840nm 880nm and 940nm. The lower wavelength ones are actually just visible so not suitable for a nest box as they will cause the birds to leave the nest.
- Optional light sensitive switching unit for LED lighting. This really is a luxury but I fitted one to this box because I like gadgets and I saw one for sale in Maplin. It is a Velleman MK125 Mini Kit that you have to solder together – a bit of fun if you like that sort of thing.
- The RCA leads will plug straight into most TVs. However, if you want to feed back to a PC, you will need a video capture device. This can be an all singing all dancing video capture card but a USB device such as the Kworld DVD Maker2 USB2.0 works perfectly well unless you’re running several feeds.
- You will need a mains power supply adapter. Most cameras are 12v and it’s important to supply it with a regulated 12v power supply. I tried cheaper ones but an unregulated supply made the camera very unhappy and produced wavy lines and patterns on the picture, so just make sure the spec for the unit states that it is indeed regulated, if it doesn’t, it probably isn’t. The camera, infrared lights, light sensitive switch and microphone combined are likely to draw less than 500mA – the camera alone will be around 120mA so aim for a 1,000mA supply and you’ll be fine.
- Finally, if you plan on having a separate microphone and infrared lighting you will also need a power splitter to divide your main power supply between the separate components. These are very cheap and will be be covered in more detail in Part 3
OK, you now have all your bits and pieces, it’s time to start putting it all together and that’s exactly what we will be doing in Part 3.
If you have any any questions or comments don’t hesitate to add them below.