Ltl Acorn 850nm, 940nm, 24 and 44 Infra Red (IR) LED arrays compared.

Fig 1:  5210A with 24 IR LED Array

Following on from my previous post which compared the FOV of the new Ltl Acorn 5310 standard and wide angle lens models, this post illustrates the differences in appearance and performance between the old and new infra-red (IR) LED arrays.

Up to now all the Ltl Acorn camera models have used a 24 LED IR light source as shown in figures 1, 2 and 3. Figure 1 shows the 5210A with 24 blue LEDs which emit light in the 940nm wavelength. These LEDs are covert and do not glow when operating.

Figures 2 and 3 show the 24 LED 850nm and 940nm versions. The white LEDs emit light in the 850nm ( nanometer ) wavelength and can be seen to glow red when viewed straight on during operation. They are visible up to 10 plus meters distance and although the IR light emission has double the range of the 940nm version they are not suitable for use in situations where the camera may be vulnerable if observed, such as security applications.

Acorn have now released their 5310 series cameras using their newly developed 44 LED array which doubles the night time light