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Native Californian, biologist, wildlife conservation consultant, retired Smithsonian scientist, father of two daughters, grandfather of 4 small primates. INTJ. Believes nature is infinitely more interesting than shopping malls. Born 100 years too late.

Sunday, January 2, 2011

Dimming the lights

Testing the Bushnell at night.

The Bushnell Trophy is a nicely designed little trail cam.

In fact, it's so little it's actually cute.

Its 32 infra-red LEDs reach out as far as 45' to dimly reveal the skulking monster buck that deer hunters dream of.

Trail cams are designed to have considerable flash range.

Bright IR lighting however is a problem at close range, especially if the trophy you seek to photograph is a 4 to 12 inch small mammal.

I decided to try to dim the IR LEDS for close-up subjects.

I reduced the number of exposed LEDS with black electrician's tape, and walked up to the cam as it snapped pictures.  

Three variants of blocking the LEDS. 

Even with 1/3rd of the LEDs blocked my image was overexposed at a distance of about 8 feet.

The bright central area is apparently designed
for photographing animals in the distance.

I moved the camera to the shed and made an obstacle course for the deer mice that dance and relieve themselves on the work bench every night,.

It's like a moonless night in there, and it smells like a rodent latrine, not that that has anything to do with the subject.

Covering the flash with opaque electrican's and camo tape dimmed the flash so much that the mice looked like shadows in the shadows.

The home-made filter with holes punched for the
ambient light sensor and motion indicator.
Even so, there was an annoying bright spot in the center of the photos.

Next I made a filter to diffuse the light.

I covered a piece of fly screen with translucent white plastic on one side and white closed-cell plastic tissue (the kind used for packaging) on the other side.

This dimmed and diffused the light sufficiently to see what the mice were actually doing -- they were dancing a jig.

The fixed focal length of the plastic lens doesn't give a sharp image by any means, but it's good enough for closeup pictures between 2-3 feet.

If I can figure out how to edit the footage I'll show you some video of the mice in the obstacle course.


JK said...

depending on how advanced of editing you need I should be able to give you hand. I have been working at over the last few days too.

Paul Whitehead said...

I see you cropped out your eyes! I too have been working with the bushnell and its difficulties.

I love its compactness and its deployability but have given up on quality - its lack of dynamic range has caused me problems both night and day.

Dan F. said...

It's very hard to find a commercial game cam that actually functions as a camera, and attempts to properly expose the image. If you look at the EXIF information for a bunch of photos, you'll see that most game cams use a fixed, short focal length, a fixed, wide-open f-stop, and a fixed shutter speed, regardless of whether the subject is a faraway mouse or a close-up snout.

I like your idea of using a diffuser to try to spread out the central cone of light these cameras throw.

randomtruth said...

Ha! You beat me to this post Codge! I too have been trying various things to reduce the flash blowout of the IR cams. Like you, I've found that the 1/8" polypropylene packing material makes a great diffuser, but is not enough on its own. So, I added a 2nd layer of slightly translucent black plastic that I created on my home printer using a sheet of clear label stock. Did this by making a black square on a slide in powerpoint, and then reduced its opacity to 75%.

The end result is about the same as yours - the overall flash range is reduced and the blowout goes away for shots/vids as near as 4 feet.

And, I'm also currently trying them on the rodentia in my yard. :)

Great work.

Camera Trap Codger said...

Actually, the cam was a bit low to get my whole head in the picture. Thanks for the feedback.

JK, I'll send you an email.

Shervin Hess said...

Hi Chris, what kind of batteries do use with the Trophy and in general? I got a Trophy a while ago and use energizer NiMh rechargeables, and they die pretty fast. Although that could be because the camera has been taking too many pictures. I use it in a marsh with lots of moving grass and the 2 GB card fills up after five hours (still experimenting)

Camera Trap Codger said...

Shervin, I've just been using alkaline AAs, but I've noticed in cold weather they don't always charge the flash and I get black/blank images without any memory used.

Bud Kay said...

It appears you are using the 2010 model with 32 sensors. I am sticking with the 2009 model (24 sesors) after the critical review by Chasinggame.com.

Anonymous said...

Honestly...I wouldn't spend another dime on Bushnell Trophy Cams. I have nine of them right now (bought into some of the hype when I read reviews on them) and they don't perform up to their reported standards. I use my for wildlife monitoring, like you do Codge, and they have caused alot of headaches. The trigger time has to be slower than advertised (I get the backsides of critters alot). The field of view is more narrow than the sensor, so there are alot of pics of nothing. The camera sometimes has trouble figuring out if it wants to use IR or not when in heavy canopy, or at dusk/dawn...and in the summer I got alot of "white-out" shots because of this. I've had several of them go into a "runaway" problem, where they snap pictures continuiously of nothing and burn up the batteries or fill the cards (usually when it gets alittle cooler out). Finally, I've had some that have straight up burned through their batteries in two weeks after only 300 to 600 pics! If I had it to do over again, I'd turn in every one of my BUshnell trophy cams for a ScoutGuard SG560. Seems to perform alot better so far, for the same price and with all the same features. Also much better customer service than Bushnell. This is, of course, all assuming one can't afford a top of the line Reconyx right off the bat(which I basically can't!).

J. Kapfer
Elon University

Tyler Montbriand said...

Hmmmm. Seems a bit of a bother, fighting to get everything just right. But I think I get what you're up to. A fixed cam means when you do get everything just so, it'll stay that way and never outguess you.

Still working on the mice pics, or did you decide you'd rather not show the internet your messy shed? :)

Camera Trap Codger said...

The mouse flicks will be premiered in a month of so. I've suspended the project for now to allow for other adventures, so the actors will be out of work for a while. I gave up on cleaning the shed.

Anonymous said...

Hey. I see this is an old post, but I have recently found a need for such a project as well. Have you tried small bubble wrap? Or any new ideas that you have found useful? Thanks. Great ideas here.

Camera Trap Codger said...

I decided the mouse pictures were NOT worth posting. The lighting may be adequate, but the quality of the videos was crappy. I moved on to home-brew DXG cameras (125s and 567s). I do still use the close cell foam filters to dim the lights though, but I think its better to use another HD camera (like the Jazz or DXGs, or even a DSLR) and install a pot on the IR array so you can adjust the lighting. White light seems to work fine too; they habituate to it quickly.