Underwater LED Lights
From Underwater Equipment
A.G.O.’s compact underwater video lights are designed to be used by divers and on small ROVs. They are suitable for inspection and surveys in both fresh and salt-water environments. All of our lights come with durable bulletproof laminated polycarbonate lenses which will not shatter due to impact or to thermal shock. The color temperature of our LED lights is 6500K, the exact color temperature at which NTSC and PAL television signals are designed to operate at. Colours illuminated by our lights do not look washed out or color-shifted. Halogen lights tend to operate in the 3000-3300K range, giving a yellow-red cast to all colours in an image.
- Solid state LED technology from LUXEON®
- State-of-the-art constant current buck-style switched power supply LED drivers for maximum LED output and lifespan
- ANSI 6400K for superior image quality and light penetration
- ANSI 5000K, ANSI 4000K, ANSI 3000K, low-power color versions available for special order
- 25 degree beam pattern with deliberate side-scatter lens for reduced hot spots, focussing lens for even light distribution throughout the field of view
- Bulletproof laminated Lexan™ lenses which will not shatter due to impact or thermal shock.
- Optional variable intensity control (OFF - 40% to 100%), controllable by external physical or virtual potentiometer
- Optional pulse or strobe control lines available for wiring into your control circuits
- Internal switching power supply, current regulated, 12 to 24 VDC input (24 VDC required for 44W versions)
- LSG-2-BCL bulkhead connector (other connectors available on special order)
- Tested to 200 meters, 1.5' with SS endcap rated to 800 meter, 2' with SS endcap rated to 600 meter
- Various mounts available, including versions for Kirby-Morgan™ helmets, hand-held mounts, pole mounts, ROV systems, towed sleds and drop cameras
- S2000V1F Single element (10 watt power draw, 660 lumen ouput)
- S2000V1V Single element (10 watt power draw, 660 lumen ouput) with variable light intensity
- S2000V2F Triple element (30 watt power draw, 1980 lumen ouput)
- S2000V2V Triple element (30 watt power draw, 1980 lumen ouput) with variable light intensity
*There might be small variations on the lumen output depending on the color temperature.
All S2000V1 models come in a 200 meter rated (500 meter collapse) 1.5' diameter (38mm) 316 stainless steel housing. Optional deep-water cases available.
All S2000V2 models come in a 200 meter rated 2.0' diameter (50mm) 316 stainless steel housing. Optional deep-water cases available.
A note on color temperature
The color temperature represents the apparent 'brightness' of the light and affects the reproduction of color in video applications. A complete discussion of this topic can be found on Wikipedia®, but in general the higher the temperature the closer to true colors you will see. 6400K lights are considered 'true' color, 5000K lights provide roughly the same colors you would see viewing an object in late afternoon sunlight, 4000K roughly the same as colors seen by moonlight and 3000K roughly the same as colors seen under an incandescent lightbulb. For reference, most common underwater lights are Halogen or HID, with color temperatures typically in the 3000K range, producing a yellow-red cast to all colors.
A note on light intensity (lumens): the lumen count represents the intensity of light apparent to the human eye, and is a useful measure of how 'bright' a light is.
A complete discussion of this topic can be found on Wikipedia®, but in general the higher the lumens, the brighter the light will seem.
For comparison purposes, a typical household 23W Compact Fluorescent Lightbulb produces about 1500 lumens, radiated in a near-spherical pattern (underwater lights are typically floodlights or spotlights which radiate in a fixed direction with varying beam angles). A typical 250W underwater halogen bulb will produce about 2500 lumens.
To determine the number of lights you will require to adequately light your subject, you need to consider the illuminance, which is measured in lux, or lumens per square meter. Your required illuminance is determined by the effective f-stop of your camera (for still cameras) or the minimum illumination number (for video cameras). Typically still cameras need ~250 lux at ƒ4 and ~16000 lux at ƒ32, while 'low-light' video cameras typically require ~0.5 to 2 lux.
For our LED lights, to calculate the approximate illuminance from each light, use the following approimate formula:
where d=distance from lens to subject (in meters) and x is a constant (0.085 for 1.5' diameter lights, 0.145 for 2' diameter lights and 0.172 for 3' diameter lights).
lux = lumens ÷ (((d + x) * tan (25° ÷ 2))2 * 3.1415)
Please note that this number is only approximate and is affected by surface irregularities, angle to the surface, secondary lighting (from sunlight or other light sources), overlap in beam patterns and other variables such as water absorption of light.
A note on light deployment: lights are affected by the turbidity of the water and the secondary lighting from surface daylight and other lights sources. Turbid water (from suspended sediments, plankton and other particulates or biologicals) is especially frustrating for videogrpahy and photography, as lights will generally cause 'hot spots' in this material which overwhelm the camera's white balance and autofocus.
If turbid water is encountered, it is generally best to reposition the lights so that the light on the intended target is indirectly applied by aiming the lights to either side of the taregt and effectively using the hot spots in the turbid material as light bounces. Secondary illumination from the lenses can also help prevent hot spots from the lux increasing as a camera approaches the target (the 'tunnelling' effect) by providing enough side scatter light for the camera's white balancing circuitry to average across the area. This is why A.G.O. lights have exposed light lenses, rather than the tightly focussed lenses common on other makes.