Like Bob I have often had people point the finger and i would love to see some
hard evidence regarding the effect.
>From my own personal experience lately with Owls and
>torches/spotlights/flashes, I have the following experiences to report. Note
>that of course they are anecdotal and not at all scientific Bob! :)
No doubt that a red light is the least intrusive to the birds.
The latest powerful white light LED torches are indeed very bright and in one
instance certainly caused the owl to "squint" and the pupils were more
contracted. I have seen alot of nocturnal birds lit up by torches etc and none
seem to deliberately turn their head away from the light source which i would
assume would be easy for them to do if it really bothered them?
Recently we watched and photographed a Masked Owl using LED torch and flash and
the bird stayed on the perch for 5minutes then flew off and hovered near us
then flew off effortlessly into the night. Anecdotally our "presence" didn't
seem to affect it. Scientifically i have no idea.
On Friday night Akos Lumnitzer and a couple of others and I were watching a
pair of Powerful Owls and there were a few flashes plus an LED torch. When i
put the red filtered spotlight on them the pupils didn't contract at all and
they were certainly not bothered. After quite a lot of photos (using flash) we
were treated to an amazing experience of watching the male feed on a
Ring-tailed Possum and then the female approached him and he fed her! Awesome
experience watching natural and intimate behaviour which quite honestly didn't
seem affected by our presence. Having said that i am not sure that if we had
shone a bright LED on them for an hour that the same could be said?? Again
nothing scientific here.
The most exciting discovery of the night was that the auto focus on our Canon
cameras worked flawlessly using only the 'dim' illumination of the red filtered
Lightforce spotlight! We were amazed as it wasn't very bright to our eyes and
the light spectrum obviously aids the way the camera AF functions. I have been
looking into bright LED lights for exactly this purpose (to be able to auto
focus with a camera) but this revelation had altered my aims. I will still look
for a brighter torch than the P7 that i own but will certainly invest in a red
filter or red LED for it. For me this will be best of both worlds - effective
photography with limited potential impact and the ability to light up the birds
for longer periods. The WOlf-eyes red filter seems to be a screw on that can be
flipped over the lens which looks like a great idea.
For an image of the pair bonding I have one on my public facebook page
It was taken with two flashes (one fired remotely) and focus achieved with red
light. Camera - subject distance was 20m (full frame with 500mm lens + 1.4x
converter)
Cheers
David Stowe
On 20/05/2012, at 2:31 PM, David Adams wrote:
> On Sun, May 20, 2012 at 11:18 AM, Robert Inglis <> wrote:
>
>> Would someone please point me towards some scientifically proven information
>> which proves that the eyes
>> and vision of birds are as susceptible to damage from exposure to very
>> strong light such as from powerful
>> torches, LED or other, and camera flash equipment.
>
> I'd like to know too. To be fair, I expect anecdotal evidence is all
> you can hope for as it would be a pretty odd science experiment to
> test out how to blind birds with light...
>
> As this is a regular thread, I'll just toss in my usual comment (one
> that does have some "anecdotal scientific" evidence going for it): it
> is easier to *spot* animals with a bright light but it is then harder
> to *observe* them. I've tried out torches and low-end night vision
> gear and the difference is pretty dramatic. With the IR-boosted night
> vision, mammals just don't seem worried. With a torch, they turn away
> and leave a lot quicker.
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