View Full Version : Infrared light
McEve
May 17th 05, 12:31 AM
Assuming the animal, or fish, in question can see infrared light, and the
pupil is able to dilate/retract - will the pupil respond to exposure to
infrared light?
I tried finding a more suitable newsgroup for this question, but were unable
to find one. Maybe somebody here knows?
Elaine T
May 17th 05, 03:50 AM
McEve wrote:
> Assuming the animal, or fish, in question can see infrared light, and the
> pupil is able to dilate/retract - will the pupil respond to exposure to
> infrared light?
>
> I tried finding a more suitable newsgroup for this question, but were unable
> to find one. Maybe somebody here knows?
>
>
I don't know the answer but IMHO it's a moot point as there are no
vertebrates yet discovered that sense infrared with their eyes. Pit
vipers "see" in infrared, but have evolved the specialized pit structure
to do so. Fish do have a highly evoled lateral line system that allows
them to detect changes in water pressure. It would be interesting to
know whether they can turn that system on or off.
--
Elaine T __
http://eethomp.com/fish.html <'__><
rec.aquaria.* FAQ http://faq.thekrib.com
NetMax
May 17th 05, 04:39 AM
"McEve" > wrote in message
...
> Assuming the animal, or fish, in question can see infrared light, and
> the pupil is able to dilate/retract - will the pupil respond to
> exposure to infrared light?
>
> I tried finding a more suitable newsgroup for this question, but were
> unable to find one. Maybe somebody here knows?
Can I assume this is a photographic question, so you mean very-near
infrared light (0.7 to 1.0um) as opposed to thermal or mid-infrared
(which doesn't penetrate glass ;~). This is a night vision question on
your breeding Zebra plecs, isn't it? (how quickly we *see through* your
question *oh bad pun*.
Snakes and some reptiles are supposed to detect infrared, but I don't
know at what end of the spectrum. On one hand, the long wavelength of
natural infrared would probably penetrate the water quite nicely, so
surface fish might have some evolutionary compatibility (or tolerance) to
it. On the other hand, I don't think it has much energy to punch through
very deeply (after all that atmospheric attenuation), so perhaps fish are
not all that adaptable to it at all (unless we are talking about top
feeders and not bottom dwellers).
Six of one and a half dozen of another ;~). Other possibilities are
sci.aquaria and rec.aquaria.tech, though you might have to post the same
question periodically until you get the right lurker/poster.
For what it's worth, other than being near-sighted and mostly having no
eyelids, fish eyes are very similar to those of the higher vertebrates,
with rods, cones and color detection. You might need to correlate
infrared effects on vision systems of more studied animals.
--
www.NetMax.tk
David C. Stone
May 17th 05, 02:01 PM
In article >, NetMax
> wrote:
> "McEve" > wrote in message
> ...
> > Assuming the animal, or fish, in question can see infrared light, and
> > the pupil is able to dilate/retract - will the pupil respond to
> > exposure to infrared light?
> >
> > I tried finding a more suitable newsgroup for this question, but were
> > unable to find one. Maybe somebody here knows?
>
>
> Can I assume this is a photographic question, so you mean very-near
> infrared light (0.7 to 1.0um) as opposed to thermal or mid-infrared
> (which doesn't penetrate glass ;~). This is a night vision question on
> your breeding Zebra plecs, isn't it? (how quickly we *see through* your
> question *oh bad pun*.
Water also absorbs very strongly across the IR band. I'm not sure
how much IR you would get in a fish tank, but I'm guessing not very
much and only select wavelengths at that.
NetMax
May 18th 05, 01:28 AM
"David C. Stone" > wrote in message
...
> In article >, NetMax
> > wrote:
>
>> "McEve" > wrote in message
>> ...
>> > Assuming the animal, or fish, in question can see infrared light,
>> > and
>> > the pupil is able to dilate/retract - will the pupil respond to
>> > exposure to infrared light?
>> >
>> > I tried finding a more suitable newsgroup for this question, but
>> > were
>> > unable to find one. Maybe somebody here knows?
>>
>>
>> Can I assume this is a photographic question, so you mean very-near
>> infrared light (0.7 to 1.0um) as opposed to thermal or mid-infrared
>> (which doesn't penetrate glass ;~). This is a night vision question
>> on
>> your breeding Zebra plecs, isn't it? (how quickly we *see through*
>> your
>> question *oh bad pun*.
>
> Water also absorbs very strongly across the IR band. I'm not sure
> how much IR you would get in a fish tank, but I'm guessing not very
> much and only select wavelengths at that.
My very limited understanding is that the longer the wavelength, the
lower the rate of attenuation. Water is blue because the shorter
higher-frequency blue is attenuated first and longer wavelength red
travels deeper. Similarly, lower musical notes travel further
underwater. Based on that logic, infrared should go further than visible
light with its longer wavelength, but longer is a relative term ;~),
water is a good attenuator.
--
www.NetMax.tk
David C. Stone
May 18th 05, 02:46 PM
In article >, NetMax
> wrote:
> "David C. Stone" > wrote in message
> ...
[snip]
> >
> > Water also absorbs very strongly across the IR band. I'm not sure
> > how much IR you would get in a fish tank, but I'm guessing not very
> > much and only select wavelengths at that.
>
> My very limited understanding is that the longer the wavelength, the
> lower the rate of attenuation. Water is blue because the shorter
> higher-frequency blue is attenuated first and longer wavelength red
> travels deeper. Similarly, lower musical notes travel further
> underwater. Based on that logic, infrared should go further than visible
> light with its longer wavelength, but longer is a relative term ;~),
> water is a good attenuator.
I think you're thinking of light scattering, which is one mechanism for
light attenuation. Once beyond scattering, though, you have to take
absorption into account. Water is very good at absorbing IR and
microwave energy.
Charles
August 18th 05, 03:35 AM
On Mon, 16 May 2005 23:39:01 -0400, "NetMax"
> wrote:
>"McEve" > wrote in message
...
>> Assuming the animal, or fish, in question can see infrared light, and
>> the pupil is able to dilate/retract - will the pupil respond to
>> exposure to infrared light?
>>
>> I tried finding a more suitable newsgroup for this question, but were
>> unable to find one. Maybe somebody here knows?
>
>
>Can I assume this is a photographic question, so you mean very-near
>infrared light (0.7 to 1.0um) as opposed to thermal or mid-infrared
>(which doesn't penetrate glass ;~). This is a night vision question on
>your breeding Zebra plecs, isn't it? (how quickly we *see through* your
>question *oh bad pun*.
>
>Snakes and some reptiles are supposed to detect infrared, but I don't
>know at what end of the spectrum. On one hand, the long wavelength of
>natural infrared would probably penetrate the water quite nicely, so
>surface fish might have some evolutionary compatibility (or tolerance) to
>it. On the other hand, I don't think it has much energy to punch through
>very deeply (after all that atmospheric attenuation), so perhaps fish are
>not all that adaptable to it at all (unless we are talking about top
>feeders and not bottom dwellers).
>
>Six of one and a half dozen of another ;~). Other possibilities are
>sci.aquaria and rec.aquaria.tech, though you might have to post the same
>question periodically until you get the right lurker/poster.
>
>For what it's worth, other than being near-sighted and mostly having no
>eyelids, fish eyes are very similar to those of the higher vertebrates,
>with rods, cones and color detection. You might need to correlate
>infrared effects on vision systems of more studied animals.
from :
http://www.aber.ac.uk/media/Modules/MC10220/visper01.html
which seems to be a reasonably believable site
Some freshwater fish can see far further into the red or longer
wavelength part of the spectrum than we can. If our eyes were as
sensitive as those of goldfish we'd see the infra-red beams that
control our TVs and videos. Whilst we are not sensitive to polarized
light, many other animals are, and must therefore see the sky as
having a far more intricate pattern than we are aware of. Of course,
we can use tools to temporarily extend the visibility of the spectrum.
some interesting stuff here
http://www.sexyloops.com/articles/colourinthefisheseye.shtml
and a big topic jump, but I thought it interesting:
http://palaeo-electronica.org/2000_1/retinal/intro.htm
NetMax
August 19th 05, 02:24 AM
"Charles" > wrote in message
...
> On Mon, 16 May 2005 23:39:01 -0400, "NetMax"
> > wrote:
>
>>"McEve" > wrote in message
...
>>> Assuming the animal, or fish, in question can see infrared light, and
>>> the pupil is able to dilate/retract - will the pupil respond to
>>> exposure to infrared light?
>>>
>>> I tried finding a more suitable newsgroup for this question, but were
>>> unable to find one. Maybe somebody here knows?
>>
>>
>>Can I assume this is a photographic question, so you mean very-near
>>infrared light (0.7 to 1.0um) as opposed to thermal or mid-infrared
>>(which doesn't penetrate glass ;~). This is a night vision question on
>>your breeding Zebra plecs, isn't it? (how quickly we *see through*
>>your
>>question *oh bad pun*.
>>
>>Snakes and some reptiles are supposed to detect infrared, but I don't
>>know at what end of the spectrum. On one hand, the long wavelength of
>>natural infrared would probably penetrate the water quite nicely, so
>>surface fish might have some evolutionary compatibility (or tolerance)
>>to
>>it. On the other hand, I don't think it has much energy to punch
>>through
>>very deeply (after all that atmospheric attenuation), so perhaps fish
>>are
>>not all that adaptable to it at all (unless we are talking about top
>>feeders and not bottom dwellers).
>>
>>Six of one and a half dozen of another ;~). Other possibilities are
>>sci.aquaria and rec.aquaria.tech, though you might have to post the
>>same
>>question periodically until you get the right lurker/poster.
>>
>>For what it's worth, other than being near-sighted and mostly having no
>>eyelids, fish eyes are very similar to those of the higher vertebrates,
>>with rods, cones and color detection. You might need to correlate
>>infrared effects on vision systems of more studied animals.
>
> from :
> http://www.aber.ac.uk/media/Modules/MC10220/visper01.html
cute
> which seems to be a reasonably believable site
>
> Some freshwater fish can see far further into the red or longer
> wavelength part of the spectrum than we can. If our eyes were as
> sensitive as those of goldfish we'd see the infra-red beams that
> control our TVs and videos. Whilst we are not sensitive to polarized
> light, many other animals are, and must therefore see the sky as
> having a far more intricate pattern than we are aware of. Of course,
> we can use tools to temporarily extend the visibility of the spectrum.
>
>
> some interesting stuff here
>
> http://www.sexyloops.com/articles/colourinthefisheseye.shtml
some interesting stuff there, and from fish lures
> and a big topic jump, but I thought it interesting:
>
> http://palaeo-electronica.org/2000_1/retinal/intro.htm
too big a jump for me, that one ;~)
So would your response to McEve (the OP) be yes?
--
www.NetMax.tk
Charles
August 19th 05, 03:25 AM
On Thu, 18 Aug 2005 21:24:35 -0400, "NetMax"
> wrote:
>"Charles" > wrote in message
...
>> On Mon, 16 May 2005 23:39:01 -0400, "NetMax"
>> > wrote:
>>
>>>"McEve" > wrote in message
...
>>>> Assuming the animal, or fish, in question can see infrared light, and
>>>> the pupil is able to dilate/retract - will the pupil respond to
>>>> exposure to infrared light?
>>>>
(snip)
>
>So would your response to McEve (the OP) be yes?
More like probably, I don't see why not. How's that for a non-answer?
NetMax
August 20th 05, 02:21 AM
"Charles" > wrote in message
...
> On Thu, 18 Aug 2005 21:24:35 -0400, "NetMax"
> > wrote:
>
>>"Charles" > wrote in message
...
>>> On Mon, 16 May 2005 23:39:01 -0400, "NetMax"
>>> > wrote:
>>>
>>>>"McEve" > wrote in message
...
>>>>> Assuming the animal, or fish, in question can see infrared light,
>>>>> and
>>>>> the pupil is able to dilate/retract - will the pupil respond to
>>>>> exposure to infrared light?
>>>>>
> (snip)
>>
>>So would your response to McEve (the OP) be yes?
>
> More like probably, I don't see why not. How's that for a non-answer?
lol, pretty safe : )
--
www.NetMax.tk
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