Welcome to Laser Pointer Forums! If you are looking for a laser you may want to check out the database of laser pointer companies. The link will open in a new window for your convenience.

 Laser Pointer Forums - Discuss Laser Pointers How powerful is 10mW? Laser Pointer Company Database     Laser Top Sites List     Lasers by Type     Green Lasers

05-21-2011, 04:49 AM #33
 Class 4 Laser Join Date: Mar 2011 Location: 20 Minutes from NYC. Posts: 15,792 Rep Power: 1573
InfinitusEquitas
Class 4 Laser

Join Date: Mar 2011
Location: 20 Minutes from NYC.
Posts: 15,792
Rep Power: 1573
Re: How powerful is 10mW?

^^^Thanks for telling me though... one less misconception to have in my head.

05-21-2011, 03:00 PM #34
 Class 4 Laser Join Date: Sep 2008 Location: Quebec, Canada Posts: 14,823 Rep Power: 477
lasersbee
Class 4 Laser

Join Date: Sep 2008
Posts: 14,823
Rep Power: 477
Re: How powerful is 10mW?

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
__________________

LaserBee Laser Power Meter Products meet your needs
at affordable Prices:
See then all here on LPF

LaserBee Power Meter products ALWAYS in Stock

Available on eBay:Check availability here..

Search

This banner is available to and can be copied/used FREE by any LaserBee owner

Last edited by lasersbee; 05-21-2011 at 03:01 PM.

05-21-2011, 05:55 PM #35
 Class 4 Laser Join Date: Mar 2011 Location: 20 Minutes from NYC. Posts: 15,792 Rep Power: 1573
InfinitusEquitas
Class 4 Laser

Join Date: Mar 2011
Location: 20 Minutes from NYC.
Posts: 15,792
Rep Power: 1573
Re: How powerful is 10mW?

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.

05-21-2011, 06:26 PM #36
 Class 3R Laser Join Date: Dec 2010 Location: USA Cali Posts: 1,196 Rep Power: 52
Krogith
Class 3R Laser

Join Date: Dec 2010
Location: USA Cali
Posts: 1,196
Rep Power: 52
Re: How powerful is 10mW?

Quote:
 Originally Posted by lasersbee 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?
__________________
--Some Pictures--

Click This Link!!! 50 mW Laser does Eye damage from his friend waving it in his face...
Above >5mW you can damage Your Eyes with a Reflection in 1/100th of a second. It Doesn't Matter How Dim it "Looks"! It is still dangerous!
Above >100 mW you can burn your retina off any glossy surface just Reflecting The Beam off to your Eye!It's More Than Just a Mirror that you need to be Careful Of!!
And remember There is Never A Perfectly Diffused Surface, Do You want to Risk it?!

Last edited by Krogith; 05-21-2011 at 06:42 PM.

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

All times are GMT. The time now is 09:10 PM.

 -- DarkShadows V5 -- Responsive LPF -2562016 -- Default Style Contact Us - Laser Pointer Forums - Archive - Top