Noldus Information Technology develop and deliver innovative solutions for the analysis of animal behaviour. This project in particular involved conducting research into the orientation and the flight patterns of insects.

“As the insects’ body and wings reflecting infra-red, a polycarbonate tracking chamber was designed consisting of black infra-red absorbing walls. By combining this with an IR illumination system, it allowed Noldus to easily identify and track the insects as they flew inside the tunnel”, says David Lambert.

Adjustable beam patterns

To ensure the project was successful, Noldus was looking for an IR illuminator which could provide high-quality illumination, flexibility and control.

First, high-quality illumination: high-quality, IR images were needed to fill the entire tunnel, with an even distribution of light which would match the narrow width and length of the tunnel. Achieving this would allow them to capture precise images so that specific detail around insect movements could be obtained.

Secondly, flexibility: being fitted to a custom-made, portable rack, the illuminators needed a degree of flexibility in how they could be mounted. Adjustable beam patterns were also important in allowing Noldus to trial different combinations and to generate the best images of the insects.

And finally control: with a number of different research aims and objectives, being able to control the light to create different conditions and scenarios was important to Noldus. All hardware elements of the installation therefore had to be able to be controlled remotely and individually to establish the best outcome.

The solution

Six Raytec Vario2-i2-1 units, together with a PSU-VAR-150W-3 supply unit, were mounted onto a custom-made, portable structure which was used to illuminate the tunnel. This structure would appear at the entrance to the tunnel, illuminating it whilst the two CCD (charge-coupled device) cameras took synchronised video images, and integrated with Ethovision XT 3D tracking software.

David Lambert stresses Noldus had successfully used Raymax 25 and Raymax 50 for previous research projects, and this on-going relationship was important in their decision to upgrade to Raytec’s Vario2 IR illuminators.

Upgrading to Vario2 allowed Noldus to control the illuminators individually. David Lambert says:

“By using the Vario remote control, they could adjust several advanced features, such as the power, remote switching, timer function, remote dimming and more. This also allowed a quicker set-up, saving cost and time during installation and ongoing adjustment.”

David Lambert also stresses that featuring interchangeable lenses, Vario2 allowed Noldus to easily modify the beam angle of each illuminator in order to achieve the best results, providing good quality, even illumination of the entire tunnel. This meant the tracking software being used could easily identify the insects, no matter where they were in the tunnel, and allowed the entire system to operate at optimum performance.

Enhanced images

David Lambert emphasises Vario2’s hot-spot reduction technology (HRT) also enhanced the images by delivering a highly diffused, elliptical beam shape to deliver more light where it was needed, while preventing overexposure of foreground objects so every insect could be monitored without disturbance to the image. He says:

“The rack was located at the entrance to the tunnel which was a restricted space. As a result, the compact size of the Vario2-i2-1 units were ideal, while still being able to provide the power required despite being the smallest sized illuminator in the Raytec range.”

According to Raytec, Vario2’s standard U bracket provided Noldus with the flexibility they required in terms of mounting. Willem Van der Veer, Senior Electronic Engineer at Noldus says:

“The flexible mounting and positioning possibilities of the Vario2 on the rack enable very good and evenly distributed light. This makes the insects visible for our cameras wherever they are within the tunnel.”