Headlight or flashlight, most of us use some sort of light when entering and exiting our hunting location in the dark. However, this piece of gear does not get much attention from hunters or magazines, especially compared to the “biggies” like our bow, arrows, broadheads, releases, and camouflage to name a few. But it should, and here’s why (now, I’m going to make a bold claim, and spend the rest of the article convincing you of this). The choice made on this seemingly insignificant piece of equipment will determine the fate of more hunts than the choices made about all the “biggies” above. Bold claim, yes. Reality is though, modern bows, arrows, broadheads, etc. are all very adequate in helping hunters take game. Your choice of light, not so much. Here is the science and why this choice is so crucial.
Being a public land bowhunter, I run into a lot of hunters, and most of them use a white light. I use a red light only. But which is better and why?
RED LIGHT OR WHITE LIGHT? – THE BIG QUESTION
To make sense of this, we need to dig a little into the science of deer vision. One could go in great depth (discussing camo patterns and how deer see them, but maybe another day another blog), but I’ll stick to the pertinent info relating to our question. Here’s what is known about deer vision from scientific research (Dr. Karl Miller University of Georgia HERE, and studies by Jerry Jacobs, Jay Neitz HERE)
WHITETAIL VISION FACTS (COMPARED TO HUMANS)
1 . Deer have horizontal pupils – this allows them to see their entire horizon (300 or so degrees) in equal focus without turning their head. A big plus for them, minus for us hunters. Because of the size and shape of their pupil this allows in much more light than ours do (human pupils being a small hole). Up to 9 times as much!
2. Deer have a layer in their eye called the tapetum that reflects light over their rods (the sensor in the eye responsible for detecting light) a second time. This allows much more light to be gathered, and due to this whitetail are at least 9 X 2 or 18 times more sensitive to light.
Deer are 18 times more sensitive to light than humans.
3. Deer see movement, not detail. Whitetail see very well, don’t have to move their head or focus their eye to do it, and see slight movements we make (which physics tells us are all reflections of light).
4. Deer have dichromatic vision (based on 2 colors, a blue and a yellow cone, vs. human’s 3 – Red, Green, and Blue cones). Cones are the color receptors in the eye. Notice the chart above. The two lines represent each cone in a whitetail’s eye. One is most acute in the violet/blue frequencies and trails off in the green, while the other is most sensitive in the green and trails off in the orange. NEITHER is sensitive in the red color frequency.
5. Dr. Miller and his team at the University of Georgia did their testing on deer starting with a food incentive, and trained deer to react, or get food, when they recognized certain color lights. Testing was done starting with white light, having all the colors/frequencies of the visible spectrum, thus known to be seen well by whitetail. (ROYGBV – remember from school that white light has ALL the colors of the rainbow)
6. Deer see 20 X better in low light conditions, when blue wavelengths dominate this ambient light (humans have a UV filter in our eyes, deer do not), . They especially see the high frequency light of blue, violet, and UV (all included in white light, except UV) very well (even a deer’s white tail looks bright blue to them at night due to this).
7. Deer cannot see low frequencies well or at all. This means red is seen as black.
APPLYING WHITETAIL VISION – SO WHAT?
So to put it all together, it is vitally important hunters use RED light and not white light if we want to remain undetected. Since deer can see white light up to 18X better than we do (just think how bright it is to us and multiply by 18), at the exact times we are using it (lowlight conditions), can see it almost every direction around them (300 degrees), and best see movement (which is what hunters are typically doing when they use it), using white light is the worst thing to use in your hunting area, period.
It’s basically like dropping a bomb in the woods, expecting the enemy to not know they are under attack, and still thinking you have the element of surprise. Fact is, as soon as you flip the switch on white light, every deer in the area knows of your presence, and will change behavior accordingly. You’ve effectively shot your chances in the foot.
Red light, on the other hand, cannot be seen by deer, and is perceived as black. I’ve actually tested this out numerous times by shining it in a deer’s eyes from my treestand, to find NO reaction. They literally have no clue. Red light is enough for us to see our path and way through the woods, and is great for getting gear set in the blind and treestand without worrying whatsoever that deer will see it or you.
And I’ll say this, if you need a big white light that you shine all around the woods to help you find your path, or treestand, it would only benefit you to prep more so you know exactly where you are going. Red colored flashlights can be found in many stores with a white light option (just in case you absolutely need it from time to time), and I suggest a headlamp for the obvious reason of having your hands free to carry and setup gear. (The only exception to using a white light I feel is in highly pressured areas during gun season. If you don’t trust other hunters, a white light helps keep you safe, as it shows up well to other trigger-happy hunters).
TRAIL CAMERAS
When applying this to trail cameras, many ask “can deer see the flash?” Some videos and pictures captured by trail cameras make it seem like the deer can see it taking the picture or were tipped off to its presence by the flash. However, most cameras are equipped with Infrared flashes, so simply looking at the low light chart above tells you the answer – there is no physical way they can see this wavelength, which is an even lower frequency than the non-visible red wavelength. If deer are looking at your camera, this either means they are curious of the shape (and you need to hide it better or put it higher out of their line of sight), or they are hearing the shutter snap the photo (and maybe you need a different brand that is quieter).
So now you know the science of why using red light is crucial in the deer woods, use them if you want to take stealth up a notch.
HIGH IQ TAKEAWAYS AND CHALLENGES:
- If you don’t have a red headlight, find one now and order it and a backup!
- What can you do to better mark, clear debris, and know your routes to and from your hunting locations so a red light is enough and you don’t need the dreaded white light?
- Check our our podcast, YouTube, and other resources DEER IQ offers HERE to help make you a greater deer hunter.
