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This week’s Flashback, from the pages of MAKE Volume 15, shows how authors Jim Moir and Ken Lange devised a camera setup to auto-trigger photos of the critters who came to visit their backyards in the dead of night. Judging from the multitude of pictures they’ve gathered over the years, there is no shortage of wildlife variety in their neighborhood. Check it out to build your own and see what’s lurking behind your house. You can also still pick up a back issue of Volume 15, the Music issue, over in the Maker Shed.

Caught in the Act
By Jim Moir and Ken Lange

Ever wonder what’s getting into your garage at night, eating your cat food in the backyard, or coming by your tent when you’re camping? Now you can find out. With a digital camera, flash, and triggering mechanism, you’ll be able to see exactly which critters are prowling at 3 a.m.

Although there are some challenges to overcome, we’ve discovered that there are plenty of solutions to develop a remote wildlife photography system that meets your needs and budget. Film cameras were used in the past, but clearly digital cameras bring this hobby to a new level by eliminating the expense, time, and effort that comes with film.

MATERIALS
Digital camera We prefer the Kodak DC-290 and discuss its benefits in this article.
Infrared (IR) detector or motion sensor
Camera flash
Power supply

What Does It Take to Do This?
Our challenge was to choose a camera system that can stay awake for long periods (most shut down after a few minutes to conserve battery power) and to rig a method for sensing the animal and triggering the shutter remotely. We also needed a flash capable of illuminating an area large enough to capture pictures of what tripped the camera. Finally, we needed power reserves big enough to run the camera, the external flash, and the animal-sensing trigger mechanism for several days.

What Camera to Use?
We evaluated the 2 typical camera types — point-and-shoot and SLR — to capture our wildlife images. Both have advantages and disadvantages. Point-and-shoot cameras are inexpensive but need a lot of modifications to work. SLRs have more features but can be pricey.

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We chose a third path and used the Kodak DC-290. This modestly priced camera was an excellent choice, with a respectable 3.3-megapixel picture and many programmable features not available in most point-and-shoot cameras. This enabled us to make the system work without extensive hacking, and at the same time kept the total system to a reasonable cost. While this camera is no longer in production, it is regularly available on eBay for $50 to $150 (depending on condition, accessories, and demand).

How We Built It
The construction process was fairly straightforward. We purchased the camera, flash, and infrared sensor, then breadboarded the control and power supply circuits, and assembled the parts into a working system. Go to makezine.com/15/diyimaging_wildlife to download the wildlife camera circuit plan and the scripts that allow the DC-290 to stay awake and trigger remotely.

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Now for some of the details:

Stay awake: The DC-290 has a programmable Sleep Time-out function that can be set to a maximum of 18 hours. Given our goal of keeping the camera awake for several days, we added our own stay-awake timer circuit that takes a picture every 13 hours — thus resetting the sleep time and keeping the camera awake indefinitely. We do get a filler picture every 13 hours but clearly this is not a problem when using “digital film.”

Triggering the shutter: The DC-290 has an electric triggering feature, allowing the shutter to be triggered without mechanical modification of the camera. We built a pulse generator circuit for the shutter, which converts the signal from the stay-awake timer (or the animal sensor) into an electrical pulse to trigger the camera from either source.

Flash: After struggling unsuccessfully to make the camera’s internal flash work adequately, we purchased a new Vivitar 285HV external flash for about $90 (it can be bought used for less on eBay). This does a great job of lighting a large area and has several adjustments that provide a variety of lighting options. The DC-290 has the option of using an external flash.

Adequate power reserves: The 4 AA batteries that powered the camera were inadequate as a long-term power supply, so we need to get power from a car battery or 120-volt AC. Our solution was to design and build an external power source capable of keeping the system operating for several days at a time. This can be more complicated than it sounds, because it has to power the camera, electric eye sensor, external flash, and stay-awake timer, which require different voltages, and because efficiency is important to minimize battery drain. Our power supply circuit is shown in the schematic diagram online.

External circuitry required: We housed the power supplies, pulse generator, and stay-awake timer in a water-resistant container underneath the camera and flash platform. The whole rig is designed to be powered by a 12-volt DC source, thus allowing the use of either a 12V car battery or regular house power run through a 120V AC to 12V DC converter.

Connecting to house power is ideal; several 100′ extension cords can be connected together to get farther into the woods. If you’re out of range of 120V AC power, 12V car batteries work fine, but you have to bring them in for recharging every couple of days.

How Does It Know When to Take the Picture?
There are 2 readily available technologies that will sense the presence of an animal to trigger the camera at the proper time.

Motion sensors: Even though these are commonly available and are used in most commercial wildlife cameras, we chose not to go down this path due to their susceptibility to false and inconsistent triggering.

IR detectors: These devices are commonly used in burglar alarm systems, and in the familiar “electric eye” that triggers a sound when a customer enters a store. They use an infrared beam that travels about 30′ and reflects off a mirror back to the sensor. When the beam is broken, a solenoid is momentarily tripped, which can be used to fire the shutter.

We found that these work extremely well since they ignore branches moved by the wind and the camera will fire within 1 second of the animal breaking the beam. By centering the beam in the photo, we found that it virtually guarantees getting a good shot of the animal. We used an old RadioShack model 49-310, but similar detectors can be found online for $25 to $50.

Maximizing Results
Whether setting up in your backyard, the open field next door, or a campsite in the woods, look for animal paths or natural narrowing points that would concentrate passing wildlife within the range of the camera and sensor.

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Be aware of scents. Move far away from human and pet habitats, as their odors may discourage animals from visiting. Food scraps and animal scents (used by hunters) may lure more wildlife to the camera and keep them there longer so you will get more pictures.

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Endless Entertainment
After 4 years and more than 8,000 pictures, we’ve accumulated quite a gallery of wildlife pictures, yet the setup continues to provide ongoing entertainment. It’s a bit like Christmas when we download the pictures every day or two and find out what was visiting the neighborhood. You may be amazed at what lurks nearby.

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About the Authors:
Jim Moir and Ken Lange are retired engineers. Jim currently teaches astronomy and engineering, and is a docent at a nature preserve. Ken enjoys riding recumbent bikes and working on his electric Fiero conversion.