Choosing a Webcam
During the last few years there has been an increase in the number of people interested in setting up their own nestcams and in response to a suggestion I have tried to set the options that need to be considered by anyone who wishes to share the magic of watching the nest building and family life of a garden bird.
1. Where to mount the camera:
(a) In the top of the box..
The most popular arrangement is to have the
camera mounted at the top of the
(b) Mounting the camera at the side of
The method has its own particular set of problems, the main one being the problem of keeping the camera lens clean. This will be best solved by including a glass window between camera and nest. However, the glass will need cleaning and any box construction needs to take this into account. I use an arrangement by which a clean glass can be slid into place as the dirty pane is removed, without creating an opening into the nest.
It is generally recommended that in open
garden situations the sector from North through east to south-east
is best for nestbox entrances. The orientation of the camera in relation
to the relative positions of the box entrance and the sun during its daily
movement can cause a problem. For example, if the box faces east and the
camera points in the same direction (as mine does) then there is a problem
of extremely bright conditions on a sunny morning. With the box entrance
facing east it might have been better if I had been able to put the
camera(s) on the south side of the box.
The Camera -
(a) Power supply
Whatever camera you choose will need power. Most require a 12Volt supply which makes them safe for use in a birdbox when used with a suitable power supply. If you buy a secondhand cctv camera, older models often require a mains (240v) supply.
(b) camera type
What type of camera would you use? A favoured type used in boxes is
board camera, which is basically a camera on a bare circuit board, There
also mini-cams which are similar, but enclosed in a protective case. Some
cameras are waterproof . I see that it is now possible to buy different
focal length lenses for board cameras, giving you the option of different
angles of view - something to think about if you are going to design a box
(c) Camera Resolution
On commercial sites the resolution of the camera sensors is usually shown as TV lines. The higher the number, the better the resolution and the more satisfying the image. Some very cheap cameras have values less than 380TVL. I would not recommend buying a camera without a resolution lower than 380TVL - there is nothing more disappointing than going to the bother of setting up your webcam only to have a image that lacks sharpness even when the camera is focused.
(d) Camera Sensitivity
The sensitivity of a camera to visible light is usually given in lux. To give you an idea of what that unit is:
The brightness of sunny daylight is >10000 lux
The amount of light falling on a surface 1 metre away from a candle is
about 1 lux
Good B/W cameras will be sensitive to visible light down to light levels of around 0.05 lux, although this 'limitation' does not apply to infra-red light.
Colour cameras are sometimes sensitive down to around 1 lux, although by then the image is usually quite poor. A few will go down to around 0.5 lux
(e) Colour or Black/White?
Do you intend to use a B/W camera or Colour? B/W has the advantage that it
can be used with infra-red lighting and so will provide an image day and
night with no visible light in the box.
Some cameras have LED light sources built in, usually infra-red versions for B/W cameras or white LED's for colour cameras. These are the most straight forward to install.
However, numerous people have had problems getting the light levels satisfactory because the light sources were not intended to be used at the short distances found in a birdbox.
Also, LED's usually act
more like spot lights rather than flood lights, giving 'hot-spots' and
corresponding dark corners. Translucent plastic can be used to help solve
This means that a to maintain a consistent level for the camera, a light source needs to be on during the day. If that source is I/R then it can remain on constantly. However, if a white light source is used for a colour camera you need to think about how and when that is turned off at night. This will be a problem if the white LED's are built into the camera.
In my experiment with a colour camera this Spring (2003) I used an white LED torch (with a plastic diffuser from a camping shop and soldered wires to it in order to operate it via a mains adaptor. This was plugged into a timer switch. Over the months the timer had to be adjusted to cope with the longer days. In tandem with that I used an IR light source which could be left on permanently.
There are going to be two cabling requirements between the box and your TV or computer, a suitable cable for the picture signal, and a power supply lead (usually 12v). Some camera kits are sold with combined leads, although you need to ensure that either these are long enough, or there are extension leads available, the connection being kept dry.
There are camera kits with a wireless link for the picture. I have no experience of these. However, you should remember that the camera still needs a power supply, and it will be important to know whether or not it uses legal frequencies to transmit the image.
(h) Sources of cameras for birdboxes
None of the camera equipment that I use was
bought new, but I have found the following two commercial sites to be very
information about the types and specifications of suitable cameras
available in the UK.
The following sites offer ready-made birdbox/camera combinations: