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^^^Thanks for telling me though... one less misconception to have in my head.
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FrozenGate by Avery
How powerful is 10mW?
- Thread starter itsmei
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Most experts say that looking into the sun for too long will
blind you..
It is known that in daylight the the human pupil is ~4mm in
diameter....
I did an experiment last year with a freshly calibrated
LaserBee II. It has an active sensor surface of 64 square
mm.
At noon... on a clear air day... I aimed the Thermopile at
the sun and got a reading of 52mW.
If the eye's pupil in daylight (assuming for this test... it will
stay dilated at 4mm dia.) has an opening area of 12.5mm
then 52mW/64= 0.8125mW/mm2....
Then 0.8125 X 12.5 = 9.75mW of sunlight entering the eye.
and at 3mm diameter the sunlight entering would be 5.68mW....
And that can cause blindness.....
Just going by the numbers.... I would be hesitant to state that
one does't need eye protection for a >5mW Laser...
Like I always say........... They are not my eyes...
I was wearing a Motorcycle helmet BEFORE it became mandatory..
That saved my life once already.........
Jerry
blind you..
It is known that in daylight the the human pupil is ~4mm in
diameter....
I did an experiment last year with a freshly calibrated
LaserBee II. It has an active sensor surface of 64 square
mm.
At noon... on a clear air day... I aimed the Thermopile at
the sun and got a reading of 52mW.
If the eye's pupil in daylight (assuming for this test... it will
stay dilated at 4mm dia.) has an opening area of 12.5mm
then 52mW/64= 0.8125mW/mm2....
Then 0.8125 X 12.5 = 9.75mW of sunlight entering the eye.
and at 3mm diameter the sunlight entering would be 5.68mW....
And that can cause blindness.....
Just going by the numbers.... I would be hesitant to state that
one does't need eye protection for a >5mW Laser...
Like I always say........... They are not my eyes...
I was wearing a Motorcycle helmet BEFORE it became mandatory..
That saved my life once already.........
Jerry
Last edited:
- Joined
- Mar 27, 2011
- Messages
- 14,125
- Points
- 113
Interesting results Jerry.
The other day I did a quick experiment to see how badly I screwed up in one of those "OOPS" moments.
I was actually just measuring my red lasers, with fresh batteries... everything went as planned... and lasers are good.
Since I was at it I also took out my 1.2W Ehgemus laser... put it about 6" from the thermopile sensor and turned it on.
The Darwin award for eye safety goes to me because I didn't change the goggles I was wearing
Of course I blinked, kept my eyes shut and turned off the laser. After I opened my eyes, basically same experience as flash blindness from a bright flashlight at night. Vision went back to completely normal in about 30 seconds. It was a close call though... IMO too close. Granted there was zero chance of a direct hit or a direct reflection, but even the specular reflection at that power is scary.
So the experiment.... I setup your laserbee thermopile, measured 6" from it, and set up a piece of hard white, somewhat glossy plastic. I then proceeded to shine the laser onto the plastic.
Sun producing 52mW.... that is interesting, and scary. I'm surprised more people don't experience problems because of it.
The other day I did a quick experiment to see how badly I screwed up in one of those "OOPS" moments.
I was actually just measuring my red lasers, with fresh batteries... everything went as planned... and lasers are good.
Since I was at it I also took out my 1.2W Ehgemus laser... put it about 6" from the thermopile sensor and turned it on.
The Darwin award for eye safety goes to me because I didn't change the goggles I was wearing
Of course I blinked, kept my eyes shut and turned off the laser. After I opened my eyes, basically same experience as flash blindness from a bright flashlight at night. Vision went back to completely normal in about 30 seconds. It was a close call though... IMO too close. Granted there was zero chance of a direct hit or a direct reflection, but even the specular reflection at that power is scary.
So the experiment.... I setup your laserbee thermopile, measured 6" from it, and set up a piece of hard white, somewhat glossy plastic. I then proceeded to shine the laser onto the plastic.
Sun producing 52mW.... that is interesting, and scary. I'm surprised more people don't experience problems because of it.
Krogith
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- Dec 12, 2010
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- 0
Most experts say that looking into the sun for too long will
blind you..
It is known that in daylight the the human pupil is ~4mm in
diameter....
I did an experiment last year with a freshly calibrated
LaserBee II. It has an active sensor surface of 64 square
mm.
At noon... on a clear air day... I aimed the Thermopile at
the sun and got a reading of 52mW.
If the eye's pupil in daylight (assuming for this test... it will
stay dilated at 4mm dia.) has an opening area of 12.5mm
then 52mW/64= 0.8125mW/mm2....
Then 0.8125 X 12.5 = 9.75mW of sunlight entering the eye.
and at 3mm diameter the sunlight entering would be 5.68mW....
And that can cause blindness.....
Just going by the numbers.... I would be hesitant to state that
one does't need eye protection for a >5mW Laser...
Like I always say........... They are not my eyes...
I was wearing a Motorcycle helmet BEFORE it became mandatory..
That saved my life once already.........
Jerry
Is this documented? I'd love to have a link in my sig with that experiment and the calculations
EDIT: In Fact Could you make a Thread with that study and have the links in my sig and a few more useful ones and Then i could replace all my safety information with your thread link?
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