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IR to White Flash Trail Camera Conversion

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Trail camera modified to take color night time videos with a white LED flash and an example photo of an opossum
Browning Recon Force Advantage (BTC-7A) with hardware and firmware modifications enabling it to take color night time videos and photos using a white LED flash. Clip of an opossum in our compost bin testing the camera on the right.

There are many cases where we would like a color photo of primarily nocturnal animals. Unfortunately, there are few choices for mid-range commercial white flash trail cameras on the market. A full blown DSLR homebrew is one possibility, but has its own drawbacks. In this post, I describe how I converted one of our favorite mid-range commercial cameras — a Browning Recon Force Advantage (BTC-7A) — from an IR Flash to White Flash. Although this was a very technical project, this post targets a general audience. I have recently added a “DIY” post with detailed instructions for performing this conversion. See: DIY: Converting BTC-7A from IR to White Flash. All trail camera photos and videos in this post were taken by this updated camera.

Illuminating Night Time Captures

To take photos and videos at night, a camera must have enough external illumination for the sensor to get a good image. Most commercial trail cameras use infrared (IR) light to illuminate the scene. So-called “low glow” units emit IR at a wavelengths of ~840 nanometers (nm) — still slightly visible as a red glow; whereas “no glow” units emit light deeper into the IR range, usually ~940 nm (nanometers). For reference, the visible light spectrum — from Blue to Red — spans wavelengths from 380 to 750 nm.

IR illumination has many advantages when used with trail cameras: the photos offer good detail; the IR illumination is close enough to the visible range that we can recognize and appreciate the resulting photos; and, critically, the illumination (especially from the no-glow LEDs) is much less visible to animals (homo sapiens, included).

On the other hand, without color, the photos can be less aesthetically pleasing. In some research situations, color variation is critical to identifying species or even specific animals. Although the white flash can startle or spook many species, some animals quickly become used to visible flashes. Finally, many trail cameras sets are far enough away from humans that a visible flash does not risk theft or vandalism.

Available White Flash Options

In the references I list the five commercial visible flash camera’s I’m aware of. Thankfully, the number of offerings in this space seems to be growing, so this list (and maybe this post!) could soon be obsolete. The Moultrie and Cuddeback models use a xenon flash tube, and can therefore only be used for photos (not videos). The Boly, Suspect, and Reconyx cameras use white LEDs and can therefore take photos and videos. The Reconyx is a great camera, but the list price of ~USD $700 is prohibitive. Both the Suspect and the Boly are aggressively priced. The Boly model even features a xenon flash tube in addition to the LED for crisp night-time stills. Neither (in this author’s opinion) is quite up to the image and build quality or ease-of-use standard set by the mid-range IR-illuminated market.

The Browning Recon Force Advantage (BTC-7A)

I chose the BTC-7A to convert from IR to white flash because we have had good success with this camera over several years. The physical design is robust and compact, and the user interface is among the best we’ve used. The BTC-7A uses a Sony IMX291 sensor, which provides excellent still and video quality even in low light conditions.

Note that Prometheus Group, Limited actually makes and sells “Browning” Trail Cameras. Prometheus licenses the Browning brand for their trail caameras. To avoid confusion, I will continue to refer these cameras as “Browning.”

The BTC-7A is almost identical to the BTC-8A (Spec Ops). The main difference is that the Spec Ops uses a “no-glow” LED Flash, vs. the “red-glow” Advantage. To do this, the Spec Ops includes glass filter over the LED array. This filter is opaque to white light, making the BTC-8A a poor choice for conversion to white flash.

Steps to Convert from IR to White Flash

Converting the BTC-7A Browning Recon Force Advantage from it’s native IR to white flash requires 3 modifications:

  1. Replacing the LED Printed Circuit Board (PCB): The factory board contains an array of 40 IR LEDs. The replacement must use white LEDs and be mechanically and electrically compatible.
  2. Disabling the IR Filter: The filter must be kept in the “engaged,” color-photo mode.
  3. Modifying the camera firmware so that it processes white LED-illuminated photos as color rather than black and white images: This last point is somewhat subtle. I’ll admit it, I didn’t consider it until I tested out my new white LED board and found that the photos and videos were still black and white.

Replacing the LED Board

The BTC-7A includes a small, satellite PCB which has 40 IR LEDs in a close-packed array. The shape is quite irregular, so I spent some time with a PCB layout tool and a set of digital calipers replicating the physical measurements in the PCB CAD environment.

Using a multimeter, I was able to figure out the driving voltage and currents for the LEDs in “low” and “normal” power modes. Using a slightly modified circuit, I designed a new board with 40 white LEDs using approximately the same driving voltages and current.

I sent the designs for the boards to a company that fabricates custom PCBs in low volumes. I then ordered some white LEDs which I hand-soldered into the new board.

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Browning Factory IR LED Printed Circuit Board shown on bottom; replacement white LED PCB I designed and assembled shown on the top.

Disabling the IR Filter

Like many trail cameras, the BTC-7A uses a high volume, 3-color (Red, Green, Blue) image sensor. How then, does it take IR-illuminated photos at night, and photos in the visible range during the day? Part of the answer is that the “red” detectors in the image sensor are sensitive to near infrared light as well. Another part is an IR filter in front of the lens controlled by a small electric motor and the firmware of the camera.

For daytime shots, the motor snaps the IR filter over the image sensor. This blocks any IR illumination in the daylit scenes from reaching the sensor. Thus, the photo we see matches the color we expect (with no “pink out” caused by extraneous IR). For nighttime photos, the motor snaps the filter out of the way, letting all light pass through to the sensor. Since almost all of the light is from the IR LEDs, the sensor only “sees” one color — IR — which it renders as black and white and shades of gray.

With a white flash, the retrofitted camera will only be taking color photos, so we don’t want the motor to move the IR filter out of the way. I considered doing this by simply cutting the wire to the motor. But, after I realized that needed to modify the firmware anyway, I ended up with the more elegant (and easily reversed) solution of disabling the motor in firmware.

Trail Camera IR to white flash conversion. IR filter and motor assembly
IR filter (red, in the center of photo) with wires from motor (black and red) to the left, connected to main printed circuit board. Note multi-color wires and connectors at top were added by the author to connect to serial debug port

Processing Illuminated Images in Color

The BTC-7A has two ways to process photos and videos. The first mode renders the photo or video in color. The second renders the image in black and white and shades of gray. Replacing the the IR LEDs with white LEDs gives the image sensor the light it needs to create color photos and videos, but it is not enough. This is because the factory firmware still processes all LED-illuminated photos and videos as black and white. The solution is quite straightforward, in principle. All we have to do is change the firmware so that it processes all images as color.

While the goal is simple, the method is more involved. Changing the firmware in this way involves 5 steps:

  1. Extracting a copy of the binary image of the firmware from the camera
  2. Reverse Engineering the the firmware binary to find the code which manages the image processing mode
  3. Making a “Patch” to the firmware that sets the processing mode to “color only”
  4. Packaging the patched firmware image
  5. Updating the camera firmware with the new image

All of these steps are fairly complicated, and beyond the scope of this overview post. If you want more details (and there are many), I am currently looking for collaborators to move from the “proof on concept” demonstration described here, to a an open source development environment and feature library which would support this modification as well as other firmware customization projects. If you are interested in this project, please let me know in comments, below.

Caveats

I have created a bit of a revisionist history in outlining the steps above. The real process included much trial and error. The “error” including the heart-breaking point late one night when I tried an unknown command from the debug serial port and accidentally erased the EEPROM on the camera. For a disconcerting period of time — maybe a day or two, I worried that I had permanently “bricked” the camera. Fortunately, I was able to borrow a second camera from our collection and do a “brain transplant” from the EEPROM of the second camera to the camera with the erased EEPROM. The moral of this story is that there is always risk in such endeavors of breaking stuff — possibly permanently.

Results

The video below features two sets — one in our back yard, and the other in a more remote location in Massachusetts. The trail camera is Browning Recon Force Advantage (BTC-7A), modified per this post for a white flash. Note that I used a video effect to turn the start of the first clip B&W to dramatize the difference between IR and white flash illuminated scenes.

Video from an IR trail camera that has been converted to use a white LED flash, thus producing color night time videos and photos.

Summary

This project to convert a camera from IR to white flash was harder than I anticipated — especially reverse engineering and correctly packaging the trail camera firmware. However, the end result is fairly simple IR to white flash conversion process: replacing the flash printed circuit board, and installing a custom firmware image from an SD card.

For those of you wondering, I did ask the folks at Browning (Prometheus) if they could release a version of the firmware with the changes listed above. As of this posting, I have not heard back from them.

Would you be interested in white-flash versions of popular mid-range trail cameras? Have you had experiences, positive or negative, with existing models? Comments, feedback appreciated!

References

Comments

IR to White Flash Trail Camera Conversion — 24 Comments

  1. Count me in on working to modify off the shelf cameras from IR to white light. Most of my older camera failures have been with the IR filter stuck in one position or another. This surely would be a way to save those cameras.

    Reply ↓

    • Great! I’m still figuring out exactly how to structure this “enterprise”. I’m thinking some sort of distributed effort. Assuming I could get you a “bag of parts” (PCB, LED, etc.), would you be willing to help write up some instructions for assembly?

      Reply ↓

  2. Nice work.

    Cuddeback also do white flash (Xenon tube).

    The exposure control on your modified Browning still works – which was certainly not a given.

    Reply ↓

    • Thanks for pointer to Cuddeback — I updated the post with a pointer to those.

      Re: your second point — sometimes it’s better to be lucky than good 🙂 Seriously, had I known (or accurately predicted) the degree of difficulty for this effort, I might never have started. Like peeling an onion, the solution of the current set of problems only leads to the discovery of another layer. Still, once you start peeling, it’s hard to stop. I did have issues with the white balance (a concept I had only superficially appreciated) in one of the inner layers. Turned out I had mis-analyzed an internal function call and wasn’t sending it all the arguments it needed — resulting in a puzzling, data dependent behavior as it consumed whatever happened to be on the stack. Truth to be told, I am also working now to find a reliable source of white LEDs that doesn’t produce a “yellow” tinged photo/video.

      Software/firmware is never done 🙂 Thanks for commenting.

      Reply ↓

  3. I echo Peter’s comments above.
    I’ve owned, and discarded, both Reconyx and Scoutguard white LED models. Our African mammals appear to be quite disturbed by the ‘flash’. This in contrast to the Cuddeback xenon flash which they generally seem to ignore. I can only guess that it is the duration of the flash that makes the difference.

    Reply ↓

    • We’ve experienced highly variable reaction to various trail camera artifacts, including variants of flash types. Certainly different species have wildly differing responses — e.g. with our local coyotes being on the most paranoid end of spectrum, and porcupines on the most oblivious. This example at least has a facile explanation, as we can imagine the locally maligned coyote being more wary of things human vs. the seldom bothered porcupines. But there are many more puzzling cases, including extreme variation of reaction among different individuals within the same species. One cannot but expect there’s a lot more going on here than meets the eye. Although there are some great references out there for how an animal might notice a trail camera (e.g. Meek PD, Ballard G-A, Fleming PJS, Schaefer M, Williams W, Falzon G (2014) Camera Traps Can Be Heard and Seen by Animals), and on this blog, I am not aware of any studies which systematically look at animal reactions. The case you mention above, of different responses to different Xenon flashes from different manufacturers, for example, seems quite baffling to me 🙂

      Thanks for reading and commenting!

      Reply ↓

    • Thanks. I’m planning on covering even more customizations for the BTC-7A (especially) in coming months, and on making the these customizations generally available. If you have suggestions on features you’d like to see, please don’t hesitate to share them here.

      Reply ↓

      • Bob Zak, Your posts are so helpful for improving trail camera videos in general I can’t believe Browning hasn’t hired you as an consultant to run quality control for ALL lines of their cameras. (Browning, this is a growing field, please consider this as a win win for all involved, it’s not to late to call him). In the meantime…Bob, you converted a Browning Recon Advantage IR LED camera to take color nighttime photos! w/ minimal increases in battery usage! and figured all the software changes! and found a way to make a new white light array and got a vendor for this! And now you asking me what other modifications I would want to see in this camera!!!!! You over deliver BEFORE we have a chance to ask a question. THANK YOU is not enough for all your hours on this, your work is very appreciated. I don’t know if I’ve got what it takes to do the mods, but you inspire me so much I would give it a try.
        I was going to send Browning a list of features I would like to see on my cameras,(starting with a digital camo strap – what I thought they could handle) but you are more likely to deliver. Here it is kind sir, my shoot for the moon list – (give me one thing off this list and I’ll be eternally grateful): turn off moon phase/pressure, keep temp. Add seconds to clock. Add picture/video number to bottom display so that it is always visible.
        Allow me to select high or low LED intensity (brightness). Allow me to select LEDs used by quadrants (left, middle, right) why? – center of close range videos are too bright, edges not bright enough, so I wonder if eliminating center LED’s might balance light over whole image. (Plus save a tad of battery power). Also settings for low, medium or high LED power might be useful for closer subjects as well. (I suspect this is harder than seems since camera constantly adjusts to available light, so maybe a way to control that too). Lastly – (as if this whole list isn’t all ready a ridiculous amount to ask for) more accurate gauge for temp and lithium battery life at the low end of the scale, where it matters most.
        If I get nothing of this list I am still grateful for all of your blogs on trail cameras. They have helped me to take better trail camera videos. Your explanations are made for a nontechnical audience which is hard to do when you are a technical person with much knowledge. Plus your explanations are well written.
        Thank you for even asking what features I would want (are you listening trail camera manufactures?)

        Reply ↓

        • Thanks for this great list! We’ll see what we can do. A couple of spoilers:

          – uneven lighting: I definitely ran into this problem with my white flash conversion. I tried a plastic diffuser, which did not work very well. What worked better were LEDs with a wider beam angle — 45 degrees vs. 25 degrees in my early prototypes (including in video featured in this post). The 45 degree LEDs basically eliminated the “bright spot in the middle problem” with first generation. Will be spec’ing these LEDs in upcoming “how to” post on white flash conversion.
          – battery gauge: You know I have an obsession with trail camera batteries 🙂 My next post will feature comparison of different battery types, including the newer rechargeable Li-ion “AA” cells you pointed me to a while back. I am also testing a prototype battery monitoring firmware fix out in the field as we speak. Stay tuned for blog post on that.

          Thanks for commenting, and keep those ideas coming.

          Reply ↓

  5. I am very interested in a camera conversion that shoots quality 4K video footage. And I would like to have the light off-camera(satelites) and divided into 2 smaller wired lights. Amazing work.

    Reply ↓

    • Thanks!

      Unfortunately, I don’t think 4K is something you can “convert” a camera to — you need to start out with a camera that supports 4K sensor, 4K processing pipeline, etc. This is not the BTC-7A (which is “only” 1080p). Fortunately, there are some 4K trail cameras out there now. Unfortunately, we had issues with early Browning versions (Edges), so I haven’t worked on any 4K cameras. Yet. I’m sure that will come.

      The satellite flash wish is doable. I can think of a couple of ways. When you say “wired lights” are you specifically asking for a wire vs. wireless? Suppose we could wirelessly sync the triggers (and therefore flashes) from 2 or 3 trail cameras (all pointed at the same target). In this case, the other one/two would act as “satellite” flashes for each of them. And we’d only need one kind of “box”. Is this in line with what you had in mind?

      Reply ↓

      • I’ve actually built that wireless “Satellite” flash for my camera and it’s working pretty well. The current issue is finding space within the camera enclosure to mount the transmitter. But standby, I’ll post a link to a video in a few days.

        Reply ↓

  7. Christmas just came early, thank you Bob!
    I’ve got lots of schooling via you tube before I try this, but I hope to give it a try. Do you have a rough guess estimate on the cost of parts for the conversion?
    Couldn’t comment on that post page so replying here.
    THANK YOU Bob for sharing all your hard work with us!

    Reply ↓

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  11. Just looked at 1st video from the field from a converted Recon Force to white LED camera. Do to tight area, camera had to be mounted closer than ideal to target – about 8 feet.
    Due to the limited area (and not wanting to remove everything in the way) this produced a very small FOV – but the white LED’s lite it up like daylight! The color reproduction was pleasing to the eye, similar to day videos. What a pleasure to view a night scene in full color, and in higher resolution than night videos. No graininess. It actually takes a bit getting used to seeing things so clearly and in color as I went through a batch of videos. A reoccurring pleasant surprise! Thank you Bob!

    Reply ↓

    • Congratulations on a successful build and first field deployment! I’d like to extend this post to include examples from folks who have made the conversion. Please email me if you have any photos or videos you would be willing to contributed (with whatever attribution you like).

      Reply ↓

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