Can deer see beam from rangefinder ?

[David T]

I'm interested in others thoughts, opinion and experiences. I've been using a pair of rangefinding bins ( Leica ) for a couple of months now. Great bins no issues there. What I have noticed is that I can watch a beast going about their business but as soon as I check its range the head is up. Happened again last night. Was watching a beast for 15min, ranged it and the head was up looking straight at me. It didn't move off but it kept checking me between mouthfuls.

i am aware of their sensitivity to the UV spectrum but can they also see the beam used in rangefinders ?

i look forward to hearing your thoughts.

cheers

D

 

[Willie]

Never noticed any reaction from the deer while using my Swarovski Rangefinders.

 

[McKenzie]

Never noticed any reaction from the deer while using my Swarovski Rangefinders.

Nor with Zeiss.

 

[Ranger22]

I've got Leica ones, can't say I've notice beasts taking any notice of me when I range them

 

[David T]

Maybe it's just me.

 

[Casual-T]

Regardless of the answer, which we may never truly know I guess, I rather like the idea of all us grown men crawling around like commandos in cammo only to then advertise ourselves once in position with a massive beam of light that the deer can plainly see... reminds me of those Far Side cartoons where the animals are always ridiculing us humans...

 

[243 Stalker]

David,

I have the Swarovski range binos and recently while sitting in a high seat had a doe come out of the wood to my left. Over the next 40 minutes I watched the doe feeding and ranged it numerous times without any obvious reaction, even when I put the dot on its head while at 27 yards.

ATB 243 Stalker.

 

[kes]

I stress this is just my opinion.
I have a night vision with Laser range finder and I cannot detect any reaction from foxes or rabbits when using it. Zeiss RFbinos dont seem to be detected either but I suspect it depends on the wavelength/frequency of the infra red light used.

Most rangefinding devices emit infra red light, normally invisible (to the human and deer eye). However, laser rangefinders (particularly and uniquely) only emit an extremely short 'pulse' of infra red light.
It would seem unlikely that an animal could see this short pulse and register a confirmed threat, even if it were in the visible spectrum, most unlikely since radiation used to 'laze' is almost exclusively within the infra-red region.
However, since the 'beam' width of rangefinders is about the size of a large door at 100yds, higher energy infrared lasers (near red) , even for an extremely short pulse length, might register, as might a distant and unthreatening sound. Most UK rangefinders seem to be well into the infra-red but maybe some are that bit more 'visible' ? There seems to be a general concensus however that deer DONT see infra-red.


Handy ref http://csep10.phys.utk.edu/astr162/lect/light/spectrum.html

 

[Strath sniper]

I have the Leica ones and can honestly say I've never seen a reaction from them....

 

[TURNBOLT]

I have the Leica ones and can honestly say I've never seen a reaction from them....

+1

 

[Dalua]

...it kept checking me between mouthfuls.

Were you eating pork scratchings? If so, it was probably hearing you.

I have the Leica ones and can honestly say I've never seen a reaction from them....

They didn't even congratulate you on your choice of high-end German optics? Shame on them!

 

[Akeld]

Have you set the laser to stun?

 

[MTLEADFARMER]

I've got the leica rangefinder binos and the 1600b. Me and a friend were checking the beam alignment using night vision and some deer wandered in the yard, we could see it reflecting off the eyes of whitetails @75 yards didn't bug them a bit.

 

[kes]

I've got the leica rangefinder binos and the 1600b. Me and a friend were checking the beam alignment using night vision and some deer wandered in the yard, we could see it reflecting off the eyes of whitetails @75 yards didn't bug them a bit.

There is a very interesting paper on the US Forestry Service trying to use blue and green lasers (in the visible light spectrum of the Electromagnetic Spectrum) to scare whitetail deer with no success at all. (The test was to see if browsing pressure/other problems could be solved by remote 'scaring'.
This suggests that even when light is visible from a rangefinder it would not alarm whitetailed deer. MTLEADFARMERS comment of course recognises that for him to see the laser reflected in the deers eyes, he had to use an infra-red device, so even though he could 'see' it, the deer, on the best evidence available so far, would not have been able to; nor would he without the device.