New high power LED lamp and tank system

[jimdiverman]

Jim,

i cant make some pictures under water, because I DON'T DIVE.
To explain the beam i will make tomorrow some pictures in my company.
I think, if you see the beam shot in 1m and 2m distance, its good enough!?

Michael

Michael,

Show us what you can, and then we will ask further questions if we still have some.

Thanks.

 

[D_B]

My understanding of Michaels comment of beam spread was that at 6 feet, it has a hot spot of about 6" to 8" wide
and if I remember correctly, if you have the reflector and lamp combined, then the 8* beam spread will be less under water due to diffraction at the air/water interface at the lense

 

[jimdiverman]

My understanding of Michaels comment of beam spread was that at 6 feet, it has a hot spot of about 6" to 8" wide
and if I remember correctly, if you have the reflector and lamp combined, then the 8* beam spread will be less under water due to diffraction at the air/water interface at the lense

So the question then becomes, how much light is in the hot spot? 50%? 75%? This is important because with a focusable beam, ALL of the light is in the hot spot. A hot spot is not the same as having a focusable beam, and in the absence of empirical data about that hot spot, I don't know how "hot" the hot spot is at 2m.

 

[D_B]

Ahh ... OK

 

[mbsub]

It will be possible for me to make a measurement of light power in LUX in the different positions of light beam.

Michael

 

[Matt S.]

Michael, thank you for participating on this board. We love hearing about new products.

I have been a big HID fan but as soon as LED gives me what I need, I am not looking back. It looks like we are getting really close! 1000 lumens is great. Like Jim though, the ability to tightly focus the beam is important to me. My home waters have poor vis and we need a tightly focused beam to cut through the water for signalling. A head with adjustable focus is ideal.

 

[mbsub]

Hello,
now i have some additional informations about our LED-CAVE with 3 new pictures.
The both beam shots shows the both power steps with the diameter of beam (40cm).
The distance between wall and lamp is exactly 2 meter.
The light power was measured in this distance. The light power in the middle of beam is:
full power -1650 lux
power step 2 - 1200 lux

in 20cm distance out of the middle is the light power:
fullpower - 800 lux
power step 2 - 640 lux

in 60cm distance out of the middle is the light power:
fullpower - 50lux
power step 2 - 20 lux

In picture "LED-CAVE" you can see the both parts of the LED-head, the adapter and the head and the charger.

Michael

 

[HenrikBP]

Michael; Nice shots. Thanks for posting them. Anyone care to guess what the actual underwater beam angle might be?

Henrik

 

[ClayJar]

Okay, given a beam angle in air of 8°, and taking the index of refraction of the water to be 1.333, using Snell's Law ( n₁ sin(theta₁) = n₂ sin(theta₂) ), with the index of refraction of air being 1, you get:

theta_water = sin^-1(sin(8°)/1.333) = 6°

8° beam angle in air should equate to a 6° beam angle in water. (Unless I did something wrong... it's almost lunchtime, and I got up early this morning. :biggrin

 

[HenrikBP]

Thanks ClayJar; I'd never have figured that out.

6° seems like a fairly tight beam pattern - a good thing I'd think, for murky waters and such.

Henrik