Project Description

Anatomy Of A NestBox Camera

A versatile camera that isn’t just suitable for popping in a nest box!

If you would love to set up your own mini/nestbox camera but have no idea where to begin then ‘here’ is a good place! Let’s start by learning a bit more about the types of cameras you are likely to find on offer and what key elements to look out for.

Lets get started…

Below are two of the most common designs of nest box camera you are likely to find. I’ve labelled up the key features and provided a little more info about each below.

The Case & Mounting Bracket

Cases tend to be of metal construction but can sometimes be plastic on cheaper models. ALL cameras of this type tend NOT to be waterproof. However, there are ways you can protect them from the elements to ensure safe operation outside. I’ll cover some of the methods I’ve used in a separate guide.

WARNING – All of these cameras tend to work on low voltage 12vDC and are supplied with a mains adapter (looks like a mobile phone charger). This adapter is NOT weatherproof so must be protected from the elements. Either use it indoors, in a shed or in a well sealed weatherproof box. As with all outdoors electrical equipment I would always recommend using an RCD breaker for added safety.

The Imaging Chip

Cases tend to be of metal construction but can sometimes be plastic on cheaper models. ALL cameras of this type tend NOT to be waterproof. However, there are ways you can protect them from the elements to ensure safe operation outside. I’ll cover some of the methods I’ve used in a separate guide.

Resolution in TVL CMOS CCD
Min Resolution 240TVL 480TVL
Max Resolution 520TVL 700TVL

There are also two different image sensor sizes used. These are 1/4″ and 1/3″. As a general rule of thumb, the larger 1/3″ chips tend to have better low light performance (but this is marginal) and offer slightly wider viewing angles compared to if the same lens was fitted to a 1/4″ sensor. This may become important if you are designing your own nest box, bird feeder cam or mammal feeding station as it will have an impact on how much space you will need between the nest box camera and the area you wish to view. This is less important if you are purchasing a complete camera system from one of the main manufacturers as they will (should) have designed the system to offer optimum views.

The Lens

The lens module screws into the case of the camera directly over the image sensor and is fixed into position by either a small grub screw or a small spring. Either securing method works well and will allow for easy focus adjustment.

Grub Screw

Spring Tensioner

Focus can easily be adjusted by gently twisting the lens clockwise or anti-clockwise. Depth of field  (the amount of the image that is in focus) will vary slightly depending on how close you focus. The closer the subject is to the camera the shallower the depth of field will be. When used in a nest box and trying to focus 150-250mm from the camera, you can expect a depth of field of approx. 100-125mm.

There are two lens angles commonly used in nest box cameras. These are 3.6mm and 2.8mm. 3.6mm lenses will give you a narrower angle of view (typically 69-92deg) but you’ll find that the subject fills the screen and looks closer. 2.8mm will give you a wider viewing angle (typically 90-120deg) which means you will see more of the inside of the nestbox but the subjects will appear smaller/further away on screen.

IR LEDS (Infra Red Light Emitting Diodes) – Nightvision

If the nest box camera you choose has infra red illumination via IR LEDs (Infra Red Light Emitting Diodes) you will be able to see black and white images at night over an area/distance dependent on the number, size and type of IR LEDs fitted. Most mini/nest box cameras have between six and ten IR LEDs fitted and will operate over a relatively short distance. This is ideal as you don’t want the IR illumination to be too powerful inside your nestbox. If it is, you will get what is called ‘white out’. This is a very bright patch in the centre of your image that totally obscures any detail. Not great to look at on screen!

There are two different types of IR LEDs used and they emit infra red light at different wavelengths. Here’s a short description of each…

850nM – LEDs emitting IR light at 850nM will give off a very faint red glow. If you were to hold your hand in front of the LEDs in a darkened room you wouldn’t see any red glow on your hand but if you were to look straight on at the illuminated LEDs you would see a number of barely visible red glowing dots. In my experience the faint red glow has no impact on the wildlife using the nest box. (However, it can have an impact on wildlife when used with general wildlife observation cameras but I’ll cover that later). 850nM IR LEDs are very bright and offer much better illumination over a wider area than the other option available…

940nM – LEDs emitting IR light at 940nM give off no visible light. This offers the opportunity to create a totally covert lighting solution invisible to humans and most wildlife. However, it is less powerful than 850nM so the distance/area illuminated is not as great. This is an excellent solution for use in nestboxes as it almost always eliminates ‘white out’.

Microphone

Most mini/nestbox cameras  these days have a highly sensitive microphone built into the housing. It’s positioned behind 1-3 holes pre-drilled into the case. Many of the microphones have ‘auto gain’ control built in. This means that when the mic is picking up very little sound a circuit within the camera will automatically try to amplify the little sound there is which may lead to a slight low level buzz being heard through your speakers. Once the mic picks up a loader noise the gain control should reduce and normal level audio will be heard.

Photocell

The vast majority of min/nestbox cameras control their infra red LEDs in one of two ways. The camera either has the IR LEDs permanently switched on or it has a photocell built in which senses the light level and automatically switches on the IR LEDs when light levels drop below a certain level.

Types Of Connector

The lens module screws into the case of the camera directly over the image sensor and is fixed into position by either a small grub screw or a small spring. Either securing method works well and will allow for easy focus adjustment.

Power / Video (BNC) / Audio (RCA)

Power / Audio (RCA) / Video (RCA)

Power is usually provided by a 2.1mm DC connector and is typically moulded in black or red plastic. If your camera has a microphone there will be a white connector attached. This is always an RCA type connection. Video connection is via the yellow connector. The video connection will either be BNC or RCA.

Other Types Of Mini Cameras

The cameras and info provided above will cover 90% of the cameras you are likely to find or use in nestboxes and other small areas.

There are other cameras beginning to appear that are becoming increasingly suitable for use in nestboxes and other small enclosed spaces. USB webcams is one example with many now offering HD quality video recording at an affordable price. However, they do have limitations including length of cable and IR sensitivity. IP cameras (cameras that connect directly to a network via an ethernet connection) are increasing in quality and decreasing in size and will soon be worth serious consideration against the standard analog cameras currently used. However, IP cameras are currently 5-10 times the prices of the analog cameras so are still out of reach for most of us!

I will be adding guides specifically for USB webcams and IP cameras over the coming weeks.

Hopefully you’ve found this introduction useful. I’ve tried to cover all of the basic information worth knowing but if you think I’ve missed anything or have a specific question relating to the above please feel free to leave a comment below.