Explorer Posted June 13, 2019 Posted June 13, 2019 1 hour ago, wiiawiwb said: SWWSAS, your encounter was during daylight. I employ my thermal only in the black of night. So black usually that I cannot see my hand 12" in front of me. In that circumstance, you would not have been able to see either creature nor move around anywhere unless you used a flashlight. I will typically sit still in the black of night for hours at a time. Endless patience. If anything moves, I'll see it with the thermal. In my recent BFF post in Field Trips 2, I told of my recent capture of a cougar via FLIR thermal imager. It was totally dark with no moon and the encounter occurred around 10 pm. The cougar did not make any sound. We saw it only because we ran into a dead deer and I told my colleague to scan the area while I approached the deer (which was about halfway distance between cougar and trail). The cougar was moving sideways instead of towards us and we can fully see its shape at a guesstimated distance of 60 to 80 ft from the thermal imager. We would not have seen or noticed it without a FLIR. Wiiawiwb, What is your strategy to stay up for hours at a time at night? I need to work on that since I tend to fall asleep when nothing is happening. Not even coffee will keep me awake when tired and cold outside (specially when I am camping solo). I do wake up with sounds, but the sounds have to be pretty loud for me to get up and start therming. 1 hour ago, Catmandoo said: ^^^^ Can you hear any noise from your thermal? My FLIR does make an electronic sound when it is booting up. Takes about 90 seconds from turning on to actually seeing an image, and meanwhile the unit makes some electronic sounds. It is like a computer booting up after all. Once it is up and running, I am not sure if it makes any sounds. I can't perceive it. But maybe it does. I have not contacted FLIR to ask. But I am happy with my unit as is.
wiiawiwb Posted June 13, 2019 Posted June 13, 2019 (edited) ^^^^ Explorer...I have the opposite problem. Since I was a young boy I've struggled to get to sleep every night. It's a curse. I find when out in the blackness of night, my mind is on overdrive listening to any and every little noise I can hear. I get "in-the-moment" and can stay there all night long. I'd like to get a small parabolic sound amplifier to aid in sound detection. To stay comfortable I have a backpacker's chair and an insulated cushion. That cushion really helps. When I press the On button, my Pulsar Helion was silently ready to go in 8-9 seconds. I timed it three times in a row. 7 hours ago, SWWASAS said: I don't know. During one encounter when I heard one moving around, I tried very hard to get it to break cover by moving towards it. I could hear thumps and thuds as I tried to close on it and it moved tree to tree away from me to maintain cover. But I never got so much as a glimpse of it broad daylight. A Flir would not have done any better than my eyes. There were a large number of blow down trees in that area that prevented me from moving very fast because I had to crawl under or over them. The only way that the BF could maintain cover that I can think of, is that it was crawling faster away from me than I was able to move towards it. If it had been upright I would have likely seen it. Finally it got tired of the game and growled at me. After the growl, one behind me broke off a tree with a huge crack. It had flanked me when I was trying to get the other to break cover. I withdrew in a direction away from both sounds which was 90 degrees from the direction I had been moving. I was lucky that direction was out into a clearcut. Neither one seemed inclined to want to show itself even to scare me off. That was the only time I thought about unholstering my weapon around a BF. The one that growled was obviously ticked at me. If either one of the two had done a bluff charge and showed itself, I probably would have gotten the gun out. Since they didn't show, I figured I was safer just moving away. In retrospect it was dumb to try to corner the BF. You take away any animals means to escape and it gets dangerous. What an awesome experience this must have been. A bit unsettling while it was occurring I'm sure. Did you have any sense of fear during this encounter or was it exhilirating throughout? Edited June 13, 2019 by wiiawiwb
cmknight Posted June 14, 2019 Posted June 14, 2019 All electronics make noise. Capacitors charge up, etc. 90% of the time we can't hear it because our hearing is limited to 20 hertz - 20 kilohertz. Animals, like dogs and cats, can hear it though, depending on the frequency, of course. Dog whistles are in the range of 23 to 54 kilohertz. They can hear a nice high shrill. We only hear the air going through the whistle.
The Truth Posted June 14, 2019 Posted June 14, 2019 4 hours ago, wiiawiwb said: SWWSAS, your encounter was during daylight. I employ my thermal only in the black of night. So black usually that I cannot see my hand 12" in front of me. In that circumstance, you would not have been able to see either creature nor move around anywhere unless you used a flashlight. I will typically sit still in the black of night for hours at a time. Endless patience. If anything moves, I'll see it with the thermal. What is your source of information that a hand-held thermal imager emits ultrasonic frequencies? I called Pulsar and was told by technical support they do not. ALL electronic devices emit ultrasonic frequencies. Whoever you spoke with at Pulsar didn't have a clue.
The Truth Posted June 14, 2019 Posted June 14, 2019 1 hour ago, cmknight said: All electronics make noise. Capacitors charge up, etc. 90% of the time we can't hear it because our hearing is limited to 20 hertz - 20 kilohertz. Animals, like dogs and cats, can hear it though, depending on the frequency, of course. Dog whistles are in the range of 23 to 54 kilohertz. They can hear a nice high shrill. We only hear the air going through the whistle. Thank you cmknight! What you said is true and a fact.
The Truth Posted June 14, 2019 Posted June 14, 2019 11 hours ago, norseman said: Not true. http://wwfgap.org/projects/thermal/index2.html Norseman - here's a conflicting article which goes into detail: https://www.insidescience.org/news/new-research-reveals-how-polar-bears-stay-warm The "hot spot" in the link you sent could be a snowmobile for all we know.
wiiawiwb Posted June 14, 2019 Posted June 14, 2019 After the capacitors charge up do they make noise? If so, at what distance do you allege that an animal can hear it....2', 20', 100 yards, 300 yards and what is your source for this information?
Huntster Posted June 14, 2019 Posted June 14, 2019 3 hours ago, Explorer said: .........Wiiawiwb, What is your strategy to stay up for hours at a time at night? I need to work on that since I tend to fall asleep when nothing is happening. Not even coffee will keep me awake when tired and cold outside (specially when I am camping solo)......... This is a huge problem for me. My body's clock is well established.
Catmandoo Posted June 14, 2019 Posted June 14, 2019 28 minutes ago, wiiawiwb said: After the capacitors charge up do they make noise? If so, at what distance do you allege that an animal can hear it....2', 20', 100 yards, 300 yards and what is your source for this information? Similar to light propagation, we have the inverse square law for sound: http://hyperphysics.phy-astr.gsu.edu/hbase/Acoustic/invsqs.html Animals have different hearing sensitivities so there is no simple answer. Other electronic components make noise. All we know is that the 'noise' dissipates with distance. The images of the inverse square law do not factor in reflectors / projectors. The equipment housings may attenuate, reflect and or project but not all frequencies equally. Layers of shielding may help but you have to test the equipment to figure out what works. There will always be noise projecting from the forward lens. Years ago, I scrapped metal trail camera mounts because I measured them and found them to be reflector-projectors of ultrasonic noise. If you have a dog(s), cat(s), parrot or wolf mix, turn on the equipment and watch their reactions. 3 hours ago, wiiawiwb said: Did you have any sense of fear during this encounter or was it exhilirating throughout? "Fear is never boring".........a quote from inactive BFF member bsruther.
wiiawiwb Posted June 14, 2019 Posted June 14, 2019 (edited) The above statements about capacitors, frequencies, and more are general information which, while being all well and good, provided no scientific testing results specifically applicable to thermal imagers. It's nothing more than classroom theory with no fieldwork results. Show me reliable scientific testing using a similar type of thermal and its affect on certain animals at specific distances and I'll gladly accept that information. It would be good to know. If animals can only hear/sense a thermal imager from 3' away, then it is falderol. If they can hear it at 300 yards, then it is critical. I'm trying to determine the numbers and therefore the impact. Can you provide test results that show the distance at which a deer, bear, or moose can hear the capacitor of a thermal imager? Edited June 14, 2019 by wiiawiwb
norseman Posted June 14, 2019 Admin Posted June 14, 2019 3 hours ago, The Truth said: Norseman - here's a conflicting article which goes into detail: https://www.insidescience.org/news/new-research-reveals-how-polar-bears-stay-warm The "hot spot" in the link you sent could be a snowmobile for all we know.
TritonTr196 Posted June 14, 2019 Posted June 14, 2019 On 6/12/2019 at 11:28 PM, The Truth said: All a bigfoot would have to do is crouch down and stay still and they would resemble a stump. It seems like it could be hiding right in plain sight and we may not even know it. Some things to consider at least. Because Bigfoot is like most every other creature. Very curious. It might sit still for a few, but it will have to move at some point even just to peak around the tree or rock to see where you are at. It has the need to keep you in it's sight at all times, that's what Bigfoot does. Bigfoot doesn't know we can't see them in the dark, this is why they still hide behind things in the darkness trying to remain unseen at night time. And we can tell from thermal footage they do this in the dark. If they are around, you will see them on a good thermal. Otherwise, they aren't there.
Catmandoo Posted June 14, 2019 Posted June 14, 2019 3 hours ago, wiiawiwb said: Can you provide test results that show the distance at which a deer, bear, or moose can hear the capacitor of a thermal imager? Nope. I do not have a thermal imager so I have not pursued it. I take care of my own equipment. I can test from 13Hz to 75kHz and magnetic fields down to 1 nano Tesla. I would attenuate everything. Literature lists hearing ranges of animals but not sensitivity relative to thermal imagers. A black bear is good for 16-->20kHz, deer about best range of 4-->8kHz. The below link lists common animals. https://www.lsu.edu/deafness/HearingRange.html 6 hours ago, Catmandoo said: you have to test the equipment to figure out what works. I suggested common animals as 'testers'. You have a powerful thermal device. This summer, you may be able to observe animals and get a feel for their awareness to your equipment.
wiiawiwb Posted June 14, 2019 Posted June 14, 2019 (edited) I'm glad this subject has been brought up because it will serve to remind me to continue to do things stealthfully even at night with a thermal. The reason I have been prodding is because a lot of people use a thermal solely to assist them to kill animals. In Texas, and other areas overtaken by feral hogs or coyote, hunters will knock them down like bowling pins. The same can be said of people in the UK who shoot fox at night for sport. The common thread among all the videos I've seen of this events is the intended prey never knew the hunters were there even though the hunters had that thermal on them the entire time. Could a sasquatch be different and significantly more sensitive or tuned into thermal emissions? Maybe. Thank you for shining light onto something I never thought about. Edited June 14, 2019 by wiiawiwb
SWWASAS Posted June 14, 2019 BFF Patron Posted June 14, 2019 23 hours ago, wiiawiwb said: SWWSAS, your encounter was during daylight. I employ my thermal only in the black of night. So black usually that I cannot see my hand 12" in front of me. In that circumstance, you would not have been able to see either creature nor move around anywhere unless you used a flashlight. I will typically sit still in the black of night for hours at a time. Endless patience. If anything moves, I'll see it with the thermal. What is your source of information that a hand-held thermal imager emits ultrasonic frequencies? I called Pulsar and was told by technical support they do not. I have heard enough anecdotal witness reports that I think BF uses the same hide behind the tree peeking and maintaining cover behavior both day and night. If so that makes it very difficult to expect even FLIR to show much of anything other than a quick peek exposing only part of a head, possibly only one eye. Two assumptions seem to be at play. Humans assume that BF disregard their peeking and hiding behind tree behavior at night and one can catch them standing in the open with a FLIR. I do not think that assumption is correct. BF seem to assume that humans can see as well as they do in the dark so they pretty much use the same behavior day or night. If the BF assumption about humans is true, then just like daytime, night BF behavior maintaining cover makes it very hard to photograph a BF. I doubt that BF knowledge about human physiology includes the fact that we may be nearly blind in the dark. That may well be why the night FLIR imaging success seems to be pretty much the same as the daytime photographic lack of success. 1
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