Understanding Underwater Video Lights

It seems like there are more kinds of underwater video lights than there are cameras for underwater video. But if you're planning on getting nice color in your underwater video, it can be a very tough decision to know which video light is right for you and why. And even then, there are some video shooters that won't need a light for their video. In this article, we'll go over why you may (or may not) need an underwater video light, what all the associated specs mean, and which lights are best for wide angle and macro video.

Why You Need (or Don't Need) and Underwater Video Light 

In water, light is absorbed at depth with longer wavelengths being absorbed more quickly in a process known as light attenuation. This leaves a lot of blue and green light laying around, giving your video a washed out blueish hue. The first and most traditional way wide angle underwater videographers add colors back that have been lost by light attenuation is to do a manual white balance with their video camera. This is done by bringing a neutral white or gray slate and "telling" your camera what white is at depth. However, a manual white balance isn't very accurate as it relies on your camera's internal "color science" (unless you are shooting RAW video). Rarely is manual white balance a good method once you are below 40-50 fsw, except with the most advanced of cameras. The second way to bring colors back into your video is to add white light at depth, yourself with an underwater video light. Often, this will produce much more vibrant colors in your video, but only where you light up your subject with the light. You also need to balance the power of your video light with the ambient light, so you need much more artificial light in shallow, clear water. In the past, this has made manual white balance the ideal choice for capturing video in shallow water (30 ft and shallower) and video lights a better choice at deeper depths. But with high power, wide angle video lights like the Kraken 8000, Sola 15000, and Kraken Solar Flare Mini, it is possible to capture great wide angle video at shallow depths and still have your scenes made vibrant by video lights...

Sample video with the Kraken 8000

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Underwater Video Lights

Understanding Video Light Specs

Unfortunately, video lights are subject to a lot of specs-based marketing without an explanation of what the terms really mean. Our mission here is to explain video specifications and identify which specs are important to consider when looking at a light. If you are ever wondering if a light lives up to its specifications, check out wetestlights.com. Full disclosure - this website is run by Light & Motion, but they do thoroughly test lights. 

Lumens

Lets start with perhaps the most confusing and misunderstood specification out there - lumens. The most important thing to understand about lumens is that it is more of a measure of power than it is of brightness. Lumens are the total quantity of visible light emitted by a light source over a unit of time. Beam angle can drastically affect the area that the light is covering, and thus lumens are not a good measurement of brightness. That being said, they can be a rough estimate of brightness if you are trying to figure out what light will work best for a certain use case. 

How Many Lumens Do I Need for Underwater Video?

This is the most common question we get from first time video shooters. As I mentioned above, it can be difficult to answer, but lumens can be a rough guide to what kind of video you can take with a light (similar to how guide numbers in strobes don't really tell you anything but you can kind of estimate what kind of photos you can take with them). 

2500 - 3800 lumens: Macro Video

2500 to 3800 lumens are good for taking macro video in deeper water where you aren't fighting strong ambient light. Generally we recommend lower powered 2500 lumen lights for smaller, compact cameras where you don't have much control over manual settings or much dynamic range from the sensor. Two 2500 lumen lights can often make for a good mid-range setup. 

4000-6000 lumens: All Purpose Video Light

4000 - 6000 lumens lights are great for all purpose video (i.e., both macro and wide angle video). However, because it's not a lot of light, you will have trouble getting good color in your wide angle video in shallow or clear water. 

8000-15,000 lumens: Wide Angle Video Light & Photography

An 8000 - 15,000 lumens video light is an excellnt choice for professional video systems and wide angle video at shallow depths. Of course, they can be used for macro video too, but their real advantage comes in when you're shooting into the sun and fighting a lot of ambient light. These video lights are also powerful enough for still photography which means you aren't limited by sync speeds from strobes. However, keep in mind that fish often get scared by high powered continuous lights.

Lux

Lux is a more accurate measurement of brightness from a light, though not often used by underwater video light manufacturers. A lux is defined as one lumen per square meter. Snoot video lights like the Divepro MP30 need a very high lux count so that you can get enough contrast with the background to create a black background. The divepro MP30 has up to 210,000 lux (lumens per square meter)!

The DivePro MP30 Snoot video Light has a high Lux

Color Temperature

Color temperature is how warm (red) or cool (blue) your light source is. Cooler lights have a higher color temperature in degree kelvin and vice versa for warm lights. There is no right or wrong color temperature for a light - it all depends on how you want to balance your foreground artificial light with the ambien light.

Color Rendering Index (CRI)

Color rendering index is a measurement of color accuracy for lights on a scale of 0-100. A light with a color rendering index of 100 would be the same as sunlight in that it would be able to reveal colors in the subject as accurately as sunlight. A very good light has a CRI in the 90-96 range. A good light has a CRI in the 80-90 range. In my opinion CRI is not as important as other measures like color temperatuer and beam angle. All lights these days tend to have a decent CRI rating. 

Beam Angle

Beam angle can make a big difference when it comes to the quality of your light. A beam angle measures the angle of coverage of the beam from your light. A wider beam angle means the light covers more area. Lights with a wider beam angle tend to have softer light than lights with shallower beam angles. Most lights will range between 90 and 120 degrees. 

What Beam Angle Do I Need for Underwater Video?

90 Degrees - 

A 90 degree beam angle is good for macro video. Lights with 90 degree beams tend to be on the harsher side which makes them great for creating contrast. Generally, you will want two lights if you are shooting very wide angle video.

100 degrees - 

These are great mid-range lights. You might be able to get away with shooting wide angle with a 100 degree light, but you'll want to spend some time positioning the light if you have just one to make sure you don't have too much of a shadow.  

110 - 120 degrees - 

These lights are great for wide angle video. With a 120 degree video light you may be able to capture wide angle video with just one light. 

Beam Type

Spot Beam - 

A spot beam is a narrow beam, usually white that is not wide enough for taking underwater video. It is great for signaling your dive buddy or for use as a focus light for photography

Flood Beam -

A flood beam is a beam that is wide enough for underwater video

Red Beam -

A red beam is great for sneaking up on critters underwater that can't see red light. It is especially useful as a focus light if it has an auto-off feature triggered by flash

Blue/UV Beam -

Blue and UV beams are great for viewing the phenomenon of underwater flourescence. Blue beams are actually slightly better for this purpose.

RGB Beam - 

RGB leds can be combined to form almost any color.You can use an RGB beam for creative photography or video, but they can be a bit gimicky and overused.

Burn Times

Most video lights by industry standard burn for about an hour. I would change your video light battery after every dive if you are shooting a lot of video. If you are shooting intermitant video or using it as a focus light, I change my battery after ever 2-3 dives. Higher lumen video lights tend to last a little under an hour, but at lower powers can last much longer.

Best Underwater Video Lights

Bluewater Photo has the best and most comprehensive guide of underwater video lights which you can check out here