problems with infrared detection of beavers

[Cees van Kempen]

Hi All,

I have a specific issue and someone might know a solution.

To collect some special shots for a beaver film I have a few GH4's in the field, that are connected to motion sensors. When something moves in the detected area, the camera is triggered and it will stop after a minute, unless the motion is still there. It works perfect with about any animal that comes in front of the camera: birds, rats, voles, deer etc. However, beavers are missed nine out of ten times. The problem is that beavers are so well insulated with their thick fur that the infrared sensor doesn't see their body heat. This is by the way the same with the 'normal' wildlife camera traps. Does anyone have a solution for this?

[Mat Thompson]

Hi Cees
That is a interesting problem. Are you talking about PIR motion sensors. If so these aren't actually looking for heat, only motion ?

Mat

[Cees van Kempen]

Hi Mat,

It are PIR sensors and they look for a combination of heat and motion. If it was only motion it wouldn't make a difference between a rat, a beaver or a leaf that moves in the wind. It is very frustrating, because sometimes beavers are doing a lot of work just a few meters in front of the camera, without detection. Whereas every mouse that passes is clearly caught on film. Occasionally it works on a beaver as well, I think when it looks straight into the camera and the PIR catches the heat from the eyes.

[Chris Medico]

The thing to do is to setup a camera with video motion detection. They will require a lot more power due to the imager running all the time but they will get the job done.

A 15w solar panel and a gel cell battery will run one perfectly well.

[Cees van Kempen]

Interesting solution. I have however invested in 3 GH4's and a GH3 that do not have this option. They are also infrared converted. Spend a lot of time and money working out a weatherproof solution with a PIR and chip that triggers both the camera and the infrared lights. I am afraid I don't have the means to do another investment in cameras with motion detection. Not sure if they exist in 4K, the size of a dslr anyway? And it would not only require more power for the camera, but also much, much more for the infrared lights. Because a camera won't detect video motion when there is no light. The large 12V batteries that power my systems work for at least 5 days when stand alone in the field, because the lights only switch on when there is motion. At least, when the motion is from another creature than a beaver :-(

[Chris Medico]

Could you set up a few of these to cover the area of interest?

Amazon.com : Outdoor 150m Sensing Distance Active Infrared Detector : Infrared Motion Detectors : Camera & Photo

[Mike Sims]

Think about replacing the PIR sensor with a Parallax X-band Motion Detector. Passive Infra Red does rely on temperature differences. The XMD is a microwave radar and does not. In many circuits it will simply replace the PIR. There is some more information here.

[Mat Thompson]

Would it / could it help to change the frequency of the IR lights your using? Or indeed light the subjects in a way that helps the PIR find its difference and trigger a detect ?

[Mat Thompson]

Also -

Maybe look at laser pointer based triggers. These are pretty inexpensive and have no lag.