Wildlife camera night time (IR) illumination modification

One of the minor issues with the night-time illumination (the IR  (infra red) lighting) of my wildlife camera is the tendency for there to be a hotspot at the centre of the image:

normal IRAs you can see, although the brightness is OK on the right side of the screen where the hedge gets closer, there is a distinct fall-off in light on the left side. However with my modification:

modified IRYou can see that the illumination is more even across the frame. The reach isn’t quite as good but this is marginal. The file data shows the same exposure and ISO settings have been used by the camera. Note that these images have only been resized – there is no change to the exposure of the image.

In this pair of images I show the side of a shed just to see how the light varies across the images without fall-off due to distance. So first is the version without modification:

flat view withot modificationThe hotspot is quite distinct. Now with the modification:

w14_103413-fresnel irStill a hotspot but nowhere near as prominent and with better illumination across the frame.

So what is this modification? I use a simple Fresnel lens taken from an old film-era flashgun and taped it over the IR light panel as shown in these two photos:

camera with IR modificationcloser view of modificationI have used adhesive tape (Scotch magic tape) as I don’t want a permanent modification to the camera. This model (from Aldi) comes with a 3-year warranty so, should the need arise, I want to be able to send it back for repair.

Simple!

A printable pdf version of this document can be seen here.