Focus Lights for Underwater Photography

An overview of this important tool for your underwater photography

By Scott Gietler

Focus lights are different from “aiming” or “modeling” lights. People using a compact camera can often get away with single-handing their camera, and will use a dive light for this purpose. Light & Motion, Fantasea, Nocturnal, Hartenberger, Sea & Sea, and Fixeye are all sellers of focus lights. These lights can be pricey. Because critters are usually shot at fast shutter speeds and small apertures, the light from a focus light often doesn’t show up in a photo. However, if you are not convinced, you can buy a focus light with a special feature - your focus light will go off momentarily when the shutter is released and your strobe fires. Focus lights also differ in their burn time, beam width, size, and intensity.

Light & Motion SOLA 600 with red light mode.

Focus lights for compact camera users

All cameras underwater, especially compacts, will have trouble focusing if the light levels are not bright. Because of this, many people use a focus light or a small dive light to assist in the focusing. I used a UK light cannon for a long time with my fuji F10, and with some practise, got fairly good at not getting "hot spots." Two good, inexpensive focus lights ($75) for compact cameras include the Fantasea 44 bulb LED (5 AA batteries) and the FIX Mini LED Focus Light (4 AAA batteries), both with long burn times. The FIX Mini light has a narrower beam, but cuts out when the flash/strobe fires.

Since many compact cameras have HD video capability, underwater photographers will often utilze a focus light that will double as a video light.  One of the most popular brands is Light & Motion.  They offer a variety of lights, which vary in power.  One of the most popular is the SOLA 600. At 600 lumens and with a red stealth-mode, many utilize this light for video and for still underwater photos.

Focus lights for dSLR users

Most people engaging in critter/macro photography with a dSLR will want a focus light mounted on top of their housing. In dark or low-light conditions, even the best cameras and macro lenses may have trouble focusing.

Other good focus light options

One of the most popular focus lights on the market today is the Light & Motion SOLA 800.  It is an amazingly compact and bright focus light. It is 1/4th the size and brighter almost any focus light on the market, and it also has a built-in red for stealth mode and a clean even flood beam.

The beam is very wide, and very even. It has 3 power settings at adjust the intensity of your lights. It can easily be used for video with a compact camera.  Best of all, the red light feature that doesn't scare critters.  The SOLA series eliminates the service hassle of o-rings and replacing batteries- simply plug it in to recharge and it is ready to go.

This photo of a blue-ring topsnail was taken using the red "stealth" mode on the SOLA 600. Attempts to take the picture using white focus light only caused the snail to retreat into its shell. Photo by Michael Zeigler.

Many people enjoy using the Fantasea 44bulb LED light as a low-cost focus light, and it can also double as a night light. I use this one and I love it, it takes 5 AA batteries and burns for 4-5 hours. In another article I compare the Fantasea to a Nocturnal focus light.

The Fisheye FIX HG20DX comes recommended, although several of my friends have flooded this light, you have to be very careful with it (get insurance). You must be very careful not get a drop of water inside the battery compartment. $420 + $100 for a spare battery pack. A friend of mine rigged a Princeton Tec dive light on top of his rig, which was very inexpensive.

A couple of my friends have purchased a Bossk big blue LED focus light and really like it.

The new small Nocturnal M220 dive light takes only 3AA batteries and can be used as a dive light or focus light.

A friend of mine just purchased an I-torch VDO focus light for macro photography and he really likes it. He says it's small, light and powerful. It takes 4 AA batteries and burns from 1.5 to 9 hours, depending on the power level (it has 3 power levels).

Make sure you check out the burn time of the focus light you are planning on purchasing, I caution you against getting a light with a low burn time. What if you are doing a long 90 minute dive, or back to back dives?

If you can single-hand your rig, you can actually use a small dive light as a focus-light, such as the Ikelite PCm, or even a canister light mounted on your wrist, using the edge of the beam.

LED vs Halogen lights

Halogen bulbs are brighter, but usually have a shorter burn time.

Do I really need a focus light?

That choice is up to you. For super macro underwater photography you definitely want one. It's a fact that all cameras, compact and dSLR alike, will have trouble focusing in low light. You have several choices, and I've seen people do all of these:

• Go without one - many compact users do this, although focusing in low-light may be difficult.
• Hold a dive light in your hand - easy to do if you can single hand your compact camera, and many people do
• Hold a small dive light in one hand, or have canister light on your wrist. this is possible even if you have a dSLR.
• Mount an inexpensive dive light on your rig.
• Use the spotting light of your strobes, but I don't recommend doing this all the time. Strobes should not always be pointed at your subject, doing so can cause additional backscatter.
• Buy a focus light, and mount it on your rig.

Will I get a hot spot if I use a focus light?

You may or may not. I'm pretty good at not getting them when I've had to use a dive light. Keep in mind that not all focus lights turn off automatically when you take a shot. One thing for sure, you'll have a bigger chance of getting a hot spot if your shooting macro at F2.8, 1/60th than if you're shooting at F16, 1/250th. Small apertures and/or fast shutter speeds block out most of the ambient light, including your dive light, especially if you are using the edge of the beam.

Further Reading

• Best underwater strobes

• Guide to macro underwater photography

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