Easily detecting the metabolic heat produced by birds, thermal imaging devices are the perfect companion for any bird watcher, no matter their skill level. Because these devices do not emit any artificial light or infrared illumination, birders are able to carry out their observations or surveys by night, without the risk of startling any birds or other wildlife.

How Can Thermal Imaging Devices Help with Birding?

Thermal imaging is an invaluable technology which works to highlight objects that would usually remain invisible in total darkness, daylight, and even in dense fog when thermal contrast is low.

Using infrared radiation and thermal energy, thermal imaging devices gather information about objects through a thermal sensor (microbolometer) attached to a special type of lens (usually made from Germanium), to formulate clear and detailed images of the observed objects.

In general, thermal imagers present their picture in grayscale – with white representing heat, black representing colder regions (or vice versa), and various shades of grey indicating gradients of temperatures between the two. However, for improved identification and differing applications, newer thermal imaging cameras are now able to add colour to the images they produce — using colours such as orange, blue, yellow, red, and purple.

What do Thermal Imaging Device Specifications Mean?

Thermal Sensor Size – Similar to digital cameras, thermal sensors are measured in pixels; generally speaking, the bigger the sensor the better the picture, as a larger sensor can capture more detail. Pulsar thermal imagers use one of three different sized sensors with its own designation: XM models use a 320×240 thermal sensor, XQ models use a 384×288 thermal sensor, and XP and XG models use a 640×480 thermal sensor.

Thermal Sensor Pixel Pitch – This is the distance between the centre of the pixels. A smaller pixel pitch results in finer image quality and a physically smaller thermal sensor. However, a larger pixel offers more sensitivity. A sensor with a smaller pixel pitch will have a greater base magnification than a thermal imager with the same size lens and a greater pixel pitch. Pulsar XM & XG sensors have a 12µm pixel pitch, and XQ and XP sensors have a 17µm pixel pitch.

NETD – Noise Equivalent Temperature Difference (NETD) is a measurement of the smallest temperature difference a thermal device can detect. The lower the value, the more sensitive the device becomes — performing better than a device with a greater NETD value in conditions that are challenging to thermal imagers such as cold, fog, and rain. A device’s NETD rating is an important indicator as to how well it will perform.

Refresh Rate – A high refresh rate (such as 50Hz) is best when choosing a thermal imager. A high refresh rate will result in a smooth image when panning or tracking fast-moving objects.

Finding the Perfect Thermal Imaging Device

Using a thermal imaging device for birdwatching/ringing will allow you to reduce disturbance of wildlife whilst observing or surveying, enables more efficient utilisation of your time out in the field, and uncovers wildlife that has until now remained unobserved on your land.

It would be difficult for us to say which model would be best you, as specifications and requirements differ from person to person — which is why we’ve compiled a list of a few highlights of models across our range of powerful thermal imaging devices that may suit your needs below.