So I am writing so good than no one can figure out that I'm not from England or USA... That is compliment. Thanks. :) OK no mucking here. My apologize...
I am member of 8 forums(domestic and foreign)... So maybe I could give some advice to you also? But I will not... I will just open umbrella instead developing thick skin next time.
About X... Forum is great stuff. You don't really have to give any data about yourself except good will because sometimes that can harm you... Less data you give about yourself the more you will be secured at www
I don’t get why green light would be any good. Mammals can see this light as it is in the middle of their visual response spectrum (just as it is with us).
As for RED light, apparently most mammals can’t see this. They don’t have the red colour receptor in their retina which we primates evolved to check when fruit is ripe.
Also, scotopic vision cells (not colour sensitive), which are in use at night, do not respond to deep red light. Or at least the light wavelength is way off the peak sensitivity (which occurs in the green region).
On the other hand, they say some birds perceive 5 or 6 primary colours, something we can have no concept of…
I’m not too sure about green either but it seems to be the Zeitgeist at the moment, particularly amongst our American cousins.
In terms of animal vision most ungulates seem to have monochromatic vision and it is said that they cannot see red very clearly. I think that this is related to contrast, considering the monochromatic nature of their vision, rather than wavelength of the light per se.
It is true that animals become lamp shy. In the UK shooting game animals at night with a spotlight is illegal but pest species may be shot with lamps, Nightvision or even thermal sights. I shoot perhaps 1000 rabbits a year under the lamp but there are professionals who will exceed that by an order of magnitude or more. The consensus is that it is not so much the colour of the light you shoot them under, it is the association of danger with light that makes animals lamp-shy. You can fool them for a little while by using different colours but they soon wise up and if green is being selected because of the improved contrast I’m not sure that is the way to go at all.
I personally use a red filter but I think it helps mainly by virtue of reducing the amount of light reaching the animal rather than any intrinsic chromatic superiority. Things that help in my experience are using the lamp as little as possible, using it as dim as possible and keeping the animal in the very edge of the beam. For particularly lamp-shy animals ( like a problem fox that has been shot at and missed before for example ) night vision or thermal sights are the way to go IMO.
Bearing in mind your location I am assuming these will be used for hogs?
Birds do indeed have very different vision to ours, it extends so far into the UV spectrum that simply washing your hunting clothes in ordinary “whiter than white” washing powder will result in you glowing like a Christmas tree to birds and one very frustrated pigeon shooter!
I’m not actually a blood sports enthusiast let me say first. I am not talking from experience like you guys. Just throwing in a bit of physiology.
Non-primate mammals probably CAN see bright red light, of wavelength less than 650nm. Their yellow-green cone cell probably has some limited response down to this wavelength, at any rate if it is similar to the human yellow green cone. But it will probably appear dimmer to them than to you. You can see this on this plot:
Red light hardly touches the retinal rods, which peak in the green -you can see this on this plot:
The bright red shooting flashlights that I have seen are all orange-red, with 625nm LEDs most probably.
What you want is a lamp with 660nm deep red LED. Non-primate, non-marsupial, mammals should not be able to see that, so they will not be able to learn a response to it.
I do take some slight objection to your calling my hallowed hobby a mere “blood sport” but that is a matter for another discussion I suppose! >)
I have read about some experiments with wavelength in the field and where they seem to fall down is that no easily portable light source is truly monochromatic enough to be truly invisible; there is always some sort of light that the bunny can see. This is the case with these notionally IR toches for use with night vision equipment: CCTV Kits: CCTV Systems & Security Cameras from Hikvision, Hilook, VALE + Ajax Alarms Even at 940nm Bugs seems to twig if you have it on him too long.
Without wishing to de-rail the thread, the UK is a bit of a Sportsman’s paradise. 8)
Basically we have tight gun laws and correspondingly loose game laws due to the lower level of hunters.
I am mainly a deer stalker but do a fair bit of pest control as a means of getting access to the deer. I also like to travel and hunt, I am fortunate to have been hunting all over the world. My last three trips were Australia for camels, Azerbaijan for Ibex and Lithuania for wild boar. I did actually have a question about hunting below –20C and batteries now that you remind me…
Cuddly: I wonder how well the experiments with the lights were controlled?
I remember reading that your cat can actually hear when an electrical appliance is plugged into the mains, because it can hear the hum caused by AC. I’ve also seen on these forums that some LEDS make a whining sound that is audible even to us humans. Given that most mammals have a supernatural sense of hearing compared to us, I wonder if they can hear the lamp rather than see it?
I don’t know mate, possibly but in the case of the vast majority of lamping it will be a DC bulb directly powered from a DC battery so no AC hum, PWM buzz, etc to be found.
I think the idea with the current fashion for green light is to do with the fact that the human eye is most sensitive to green, therefore you can use less of it and the less light you use the less likely the beast is to pick it up.
the response graphs you posted illustrate another point which is that although the peak response is at xnm, there will be a response albeit much less, at a very wide range of wavelengths to either side of x. In fact there seems to be more or less a normal distribution of response vs wavelength.
Nocturnal animals have various adaptations in their eyes that make for a much greater sensitivity to photons entering the eye than humans. The presence of a tapetum lucidum for example is what enables us to lamp them and get eye shine back giving away their position without the need to fully illuminate them. However if you can see eye shine it must mean that enough photons are entering the eye that enough are being reflected back for them to be visible to you. In these circumstances it is quite possible that the animals can see “light” of some description or another as some of the photons will have been absorbed on their journey in to and then out of the eye.
Yes I can only think that is the reason for green light. But like you say, nocturnal mammals are probably even more sensitive to low level green light than we are.
Another reason this idea may have developed is that night vision goggles are similarly most sensitive in the green.
I’ve been sad enough to spend ages Googling for 660nm flashlights. There’s a lot of laser pointers but I have only found a few flashlights that claim to be at this wavelength. Most of them are astronomy lights that take 9V batteries. But I did come across this oddity below, which says it is a reasonably bright 660nm flashlight, and it looks like it takes 2x18650s. I feel sorry for the goat in these pictures.
