The last bunch of UV-Killer Tests
UPDATED TESTS
The purpose of this report is to document additional tests I made on the UV-Killer product samples sent to me by Dan Gutting of Atsko, Inc. Let me repeat at the outset that I was on the record as highly skeptical of not only the claims of Atsko regarding this product. In fact the reason for this test grew out of a weblog entry I made on 9/22/2008 on Genesis 9:2-4 Ministries. Dan took umbrage with my assertions, and a conversation ensued. If you follow the link, and click on the comments, you can see what has transpired. Eventually Dan offered to send me a sample of UV-Killer to test. After the first set of tests,UV-Killer Test 081106 , Dan reviewed the results and decided to send me additional material, specifically three light sources:
- A compact fluorescent bulb
- An LED bulb
- A small key-fob LED flashlight that would be suitable for testing samples in a store or in the field.
All three seem to produce a heightened effect of UV fluorescence compared to the 75 Watt incandescent bulb I had used in the earlier tests. It definitely gave me reason to go back to the lab. Please refer back to the 11/6 tests for all the setup information. The compact fluorescent bulb made for the best illumination for photography. I therefore used that for the follow-on tests. I honestly expected to be eating crow by the time this was over.
Through all of this, this was just me in the basement with a light bulb and a camera. No deer were killed in the course of this test.
Here are the details: UV-Killer Tests 081211
My conclusions:
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After all this testing , do I believe the UV-Killer can darken the UV fluorescence of your clothing? Yes. |
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Do I believe there are UV-Brighteners in detergent? Yes. |
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Does UV-Killer do anything to them? I couldn’t get the glow of washed clothes to read on my camera in the first place. Therefore, I was unable to test it. The one positive test was a glob of Ultra-Gain that had been left to dry on a patch of cloth for over a month. That is hardly a valid test on which to base an opinion. |
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Do name-brand manufacturers produce camo that has UV-Brighteners. Yes. |
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Does UV-Killer reduce their fluorescence? Yes. |
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Does it amount to an appreciable amount? No. It does on copier paper, but I did not see a level of attenuation that I would consider substantial on the fabric. On camo fabric, that is already pretty dark. The attenuation is there but it only muddies the pattern. After the fabric if left to dry, I do not see appreciable darkening of UV fluorescence. |
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After all this testing, and after 26 seasons of hunting do I think UV-Killer really does anything to enhance my chances of bagging a deer? I am wholly unconvinced it does. If a deer is scrutinizing me enough to see the difference, I am all ready busted. Either that or he’s already on a one-way trip to my freezer. |
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What would convince me? A double-blind test that shows conclusively that deer will run from a hunter wearing clothing that is not protected with the UV-Killer product versus a control. I would think a 20% difference would be reasonable to expect. I doubt you will see that study ever done. |
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Do I have any suggestions: Yes, If you have a concern about this sort of thing, stick with dull camo patterns without a whole lot of contrast. Those bright white highlights are bright for a reason. Wash your clothes in sodium bicarbonate, and stay away from laundry detergents. What? You want brighter hunting clothes? Duh! A little dull and dingy goes a long way. Remember that almost my entire collection of camo clothes and camo fabric, collected since 1982 had a very small percentage of samples that would glow under the bulbs supplied by Atsko– even a lot of the hunter orange stuff appeared dark under UV. |
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I had commented on your old site about my thoughts on UV killer.
see here for my comments:
http://blackholecoffeehouse.blogspot.com/2008/11/uv-killer-tests-elephant-repellent.html
You suggested I comment here so I looked for the most likely post and this is it. 🙂
As far as UV Killer goes, I figure it’s worth it if you can do it once and forget it. It has been that way in the past. But now with my latest bottle, it doesn’t seem to be doing anything because it is so thin, as I posted at the old link. I think it probably does better on natural fabrics than synthetics, but I have no orange cotton to use it on to test. Everything is synthetic whether it’s fleece or a polyester orange vest.
I think I will go to the fabric store and bring my UV light with me. I’ve done that before. And buy plain bright orange fabric that doesn’t show built in UV brighteners like all the orange camo at the sporting good stores does.
If you’re rifle hunting, I don’t think it matters for the most part. You have a lot longer reach than you do with a bow. I think with bowhunting, I’ll take any edge I can get (within reason and the law) to fill the freezer. And they always seem to come out where you aren’t expecting them. If it gives me 2-3 seconds more to get off the killing shot at close range, I’m ok with that. But this new formulation of UV Killer doesn’t seem like it will do that.
Thanks for responding. I just moved my weblog over here and I thought your comments were worth having.
I’ve been arguing that this whole UV-Killer thing is a bunch of hooey for several years now. One of my more recent discussions was at D&DH:
http://forum.deeranddeerhunting.com/tm.aspx?m=84179&mpage=1
Let me give you one of the highlights:
“. . . When we talk about UV Brighteners in our detergents and used as pigments in our clothes, we’re actually talking about a substance that absorbs light in the UV part of the spectrum and then fluoresces in the visible part of the spectrum. If it actually fluoresced in the UV part of the spectrum, we would not be able to see it.
An apple absorbs all the colors of the spectrum, but it only reflects red. That’s what makes it red. That’s reflection. Now think about an apple that took in blue light and glows red or orange or white– now you’re talking fluorescence.
When we see a black light, like a bug zapper what we see is the visible part of the total light coming from that bulb, the UV component is invisible to us. We see the blue or purple light, but that’s not UV. Then we put a white shirt , or a blacklight poster, or a piece of camo under the light and we see parts of it glow, that’s a visible manifestation of UV hitting the object, but what we’re seeing is always visible light. It’s not UV. Now, we go and spray on some UV-supressant and the visible glow goes away. What does that prove? Have we really made the UV disappear, or have we made the visible light fluoresence disappear? The answer is the latter.
The whole thing is a bit of quakery, . . .”
Here’s another idea from the thread:
” . . .
The University of Georgia study only showed that deer had the photoreceptors in their eye that would be sensitive to UV light. It did nothing to prove that deer could actually resolve the light into an image. In fact, the way a mammalian eye is set up, you’d not be able to focus the UV light along with the visible light. Nowhere have I seen a study that links deer behavior to UV.
Here’s the much-quoted Georgia study from the Atsko Site:
http://www.atsko.com/articles/hunting/how-game-animals-see-smell.html#deervisioninbrightlight
Please, somebody show me where the University of Georgia tested the hypothesis that deer run like scalded cats when they see UV light? Run like apoplectic weasels towards the light? Do anything but continue munching their cud like contented cattle? No. In fact the U of G study has not a wit on deer behavior.
Go ahead and burrow through the Atsko site and let me know when they show the study where deer run away from sources of UV radiation, beyond their normal aversion to bright sunlight.
Before we go throwing around “scinetific facts” I would just like to say that so far, the best research has only been able to show deer probably can sense UV light. However, before we go boldly into the leap that somehow UV causes them to have adverse behavior, remember this:
When is UV radiation from the sun at its maximum? At Noon.
When is UV radiation from the sun at its minimum? At Dawn and Dusk.
When do most hunters encounter deer? Dawn and Dusk
When do most deer curl up with their cud? Noon.
Why should hunters worry about UV Radiation? Sunburn.
Beyond that? I dunno. Somebody tell me where the studies are.
Where does UV radiation come from? The sun.
Where is the sun? In the sky.
Given that an animal might be able to sense rays coming from the sky, and a hunter was up a tree and skylit, would it be untoward for that hunter to wear camo that might radiate in the same part of the spectrum as the sky?
I don’t mean to be a grump on this, but please show me where all the “scinetific facts” point. I believe that white golf shirts fluoresce under bug lights, but why does that mean that deer hate my camo? ”
Paula, what really got me torqued out of shape is that Atsko contacted me to try the stuff. It didn’t work. I said so. Atsko then said I was using the wrong bulbs, and he sent me some. I repeated the test with camo swatches I’ve compiled over nearly 30 years of deer hunting. I could not get a significant test that would confirm their claims. I’ve talked to other outdoor writers. They’ve had the same results. However, when we try to publish our findings. . . well, I got a spanking from one magazine and nearly lost my pro-staff appointment. That publisher had just published a book that had a whole chapter on UV-suppression.
Look at my latest deer kill, and all the ones over the past 10 years. The pictures are posted to in the right column I’ve been wearing a Hunter Orange poncho and a Hunter Orange hat that is positively radioactive under Atsko’s bulbs, and yet deer regularly walk under my stand like I’m not there. I’m not debating that they see UV or not. They might What I am saying is I don’t think they give a hoot. Not one study, on Atsko’s site or anywhere else, shows deer have an aversion to UV.