Camera Trapping for Scientists – the alternative way

Recently a friend of mine posted a question on Facebook regarding alternative solutions to camera trapping rather than the off-the shelf trail camera providers. The main reason being that the quality of the photo’s are not good enough, they do not shoot in RAW and the resolution is often just 5-8 megapixels – way too low if the photos are needed for promoting the research of a specific conservation program even if it is functional for species identification.

Now, whereas the person in question know how to build their own using a DSLR they needed something less complicated for their parabiologists to use that still produces photos of a high enough quality. I suggested two solutions and though that I would write them up and post them here. The first one is a lot simpler and suitable for parabiologists, whereas the second one is cheaper and will hopefully improve the field significantly in the future.

1: Hacking a Canon camera for use as a camera trap

Pregnant deer caught by a camera trap. Image is from MammalWeb.

That’s right! Because there is something called the Canon Hacker Development Kit (CHDK). These hacks only work on the point and shoot range but can for example extend the settings to incorporate the ones available on the DSLR range. Multiple point and shoot Canons can do RAW formats and you will certainly be able to find one that shoots higher than 8 megapixels. Now you need to ensure that you know the correct firmware on the camera, as the type of CHDK you need to download will differ between the different ranges of camera. There are two different main scripts:

There is also a low light solution which can be read about on this forum thread.

To install the script, you download the script and then load it into the CHDK scripts folder. Now you can load the script, set the parameters and finally use the script by following the steps on the CHDK page (they are relatively simple). For some newer Canon versions ACID is needed instead.

If this was so great, would it not have been used by some scientists already? Well, it has! So you can read either the scientific paper or the blog.

Racoon caught by a camera trap. Image is from MammalWeb.

The great thing about CHDK is that users can develop their own script for the Canon cameras–allowing for new innovations. The camera can also be used for multiple things, not just as a camera trap.


2: Setting up a Raspberry Pi as a camera trap

Saad Chinoy’s write up of using his R-Pi as a camera trap during the Dinacon conference 2018. Copyright Saad Chinoy (to see more updates from Saad follow @saadcaffeine on instagram).

If you haven’t heard of microprocessors in the open-sources hardware community before, then here’s your first introduction! There are multiple models such as Arduino, Micro Bit and of course the Raspberry Pi. They are a very tiny computers at a very small price, with an excellent open hacking and code developing community online. Part of the movement is to make computers available to everyone but also teach coding. In short, they can be used for a lot of things!  Let’s focus on the camera trap. First you need a Raspberry Pi, a Pi Zero is probably adequate and they are only around 5 USD. Secondly you need a Raspberry Pi camera (sorry! sadly the USB cameras won’t work) which is around 30 USD. If an IR sensor is needed, they are around 6.50 USD. Unfortunately, these cameras are only 8 megapixels, but hopefully in the future we’ll see some better ones coming out, or someone providing a hacking solution for an easy to use higher resolution one so considering the low cost these are worth putting out there as a potential solution.

The camera trap itself, the R-Pi board is behind the description but the camera itself is hanging over the front. From the Dinacon conference 2018. Copyright Saad Chinoy.

I’m going to give links to a script that I’ve seen someone use that seemed to be working fine, however, this is a lot more complicated to install and set up than the Canon! The benefit is that you have a much wider range of how to set up the script (full list on the wiki page). You can choose between video or images, single or multiple images . The camera settings can still be controlled and if needed you can schedule when things are going to be captured. An additional benefit? You control it from a computer after the initial installation and can see photos in real time or just get them uploaded. Great if you have WiFi nearby as they can auto upload, less good if you are in the middle nowhere.

For an alternative with a suggestion with a housing solution see this post. If you are just interested in building a camera scratch see this Adafruit post.

Whereas I do not think this is the best solution for parabiologist at the present time, I think we will see some major advances in this arena soon so hopefully we will see some new and cheaper camera traps with better components getting developed and tested. The major benefit of using a Raspberry Pi? Well, once it is not needed as a camera trap anymore you can just put in an SD card loaded with something else (or wipe the one used for the camera trapping) and then the sky is the limit as to what you do with your computer. The Raspberry Pi community is a huge open source movement with open-source hardware and scripts constantly being developed. If nothing else, giving one to a child and getting them to follow some online tutorials or getting them a basic starter kit of sensors and cables is a great way to get them knowledgeable in coding.

3: Get super swanky and make your own 360 camera trap

While these inventions do exist, they are pricey! Luckily, once again, you can potentially hack a point and shoot camera, if it is capable of taking 360 degree photos. If you want to know more head over this instructables page created by the amazing Andrew Quitmeyer on how to put one together using a 360 camera, an Arduino and some motion detectors (or just watch the movie below).


Thank you to Saad Chinoy for input, Scott Trageser for the initial question and to everyone that participated in the discussion online!

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