LED light

To: Birding Aus <>
Subject: LED light
From: L&L Knight <>
Date: Sun, 4 Oct 2009 13:45:23 +1000
Sorry for coming in late on this one. I was visiting some relatives who live in the wet tropics last week. We did a bit of spotlighting, looking for Large-tailed Nightjars at dusk with a red lens cover over the light. We saw a few in flight and picked up their eyes as they perched in distant trees.

My cousin was of the opinion that many animals don't see so well at the red end of the spectrum. He backed up this assertion by later bagging a large boar that we had seen fossicking about his property (he had the spotlight fixed to the top of the scope of his rifle). He said he could get a lot closer to the pigs with the red lens cover than he could if he were using a white light. I had a look at the beast the next morning - it appeared to be about 1.4 metres long and had a nasty pair of tusks.

Regards, Laurie.

On 20/09/2009, at 11:15 PM, Chris Sanderson wrote:

Hi Greg,

There's been a bit of info posted in the archives on this before. Dr Jack Pettigrew at UQ has done some research on both nocturnal mammal and bird
eyes and has suggested while bird eyes are more sensitive to low light
conditions, they are also more robust than human eyes. Light in their eyes can interfere with feeding behaviour, though I'm not sure how much of an
impact it has.  Nocturnal mammals on the other hand are susceptible to
retinal damage, and this has been seen in some individuals in the Atherton Tablelands that were on regular spotlighting tour routes a while ago. One suggestion is to use a red filter (or red cellophane) over the front of the torch, which helps avoid the eye damage. Combine this with a technique of shining the light only briefly onto the animal and try and keep the main
beam away from the face once you've confirmed an ID.

In terms of eyeshine, LED light does produce a shine, but as you suspect, its not as great as standard halogen lights (in my experience at least).


On Sun, Sep 20, 2009 at 5:01 PM, ninderry <> wrote:

I recently acquired a LED Lenser 14 flashlight to supplement by
gear, thinking to use it essentially as a camping torch, and was surprised at how powerful the beam is. The range and brightness of the beam rivals my battery spotlight. I was wondering if anyone has experience with these Led Lensers with spotlighting. It's a very white light and the instructions include grave warnings about shining it into the eyes of people, so I was wondering if there was any reason to think the light might damage the eyes
of nocturnal critters. Also, I'm not sure if the light will reflect
as well as the standard gear. Any suggestions?

Greg Roberts


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