SeaLife SL960D Digital External Flash (Strobe) Review
July 11th, 2006
I’ve gotten by quite well over the years with my cameras’ internal flash. However, shooting underwater photos in adverse conditions, such as poor visibility and over larger distances, requires more horsepower. That’s why I decided to add to my photographic arsenal an external digital strobe from SeaLife, the SL960D. This unit is not only rugged and easy to use, but is also quite affordable and offers the promise of extending the range of potential subjects. You can view the results of using the strobe by visiting my recent photo gallery from Hood Canal (versus the album from Costa Rica, taken by the same camera with no strobe - keep in mind that visibility was about 3x greater in CR).
A little background
Photography is a complicated undertaking when one tries to venture into the depths of the Ocean. Water refracts and absorbs different wavelengths of light at at different rates. As you descend the longer wavelengths are lost first (remember ROY-G-BIV: red, orange, yellow, green, blue, indigo, violet). So, red is the first to go with the others following suit until all you’re left with are different shades of blue.
There are two ways to compensate for the loss of natural colors:
1) Manual Calibration of White Balance (to be covered at another time).
2) Bring a light source with you.
Strobes
Strobes are externally mounted flash bulbs that aid the diver/photographer in casting a broader, more powerful light on his/her subject. These are mounted away from the lens of the camera to reduce backscatter. Oftentimes, these strobes are designed to be very powerful so that the photographer can shoot subjects from a large distance. The result of using an external flash at any distance, are richer, deeper colors and finer detail overall. Though using a strobe entails a bit of learning, the results speak for themselves.
SeaLife SL960D
The SeaLife SL960D is a digital external flash, or strobe, that is very reasonable in price and offers great performance and versatility.
Prominent Features:
- Deeper, richer colors and reduces backscatter.
- Works with digital cameras that have up to 4 pre-flashes.
- Variable power adjustment for correct image exposure.
- Includes Flash Link optical cable connection.
- Flexible, rubberized arm for easy aiming and sure grip.*
- Deluxe carry case included.
- Universal mount fits all SeaLife cameras and other underwater camera housings with tripod mount.
- 5 pre-flash cancellation settings.
- Effective underwater distance range from 2 to 8 feet (0.6 to 2.5m).
- Two Digital Flashes can be mounted to each side of camera.
- Depth rated to 200 feet (60m).
- Approximately 100 flashes with 4 AA batteries.
The SL960D works with a great number of camera/housing models, including my Canon SD500 Digital Elph & WP-DC70 Housing, and other models from Canon, Pentax, Olympus, Sony, Nikon, Fuji, Minolta and Casio. The strobe simply screws into the bottom of the housing (via the tripod mount). You then run the provided optical wire from the strobe unit to a fitting that sits in front of your camera’s internal flash (I found it helpful to secure the optical cable with electrical tape, to avoid accidentally dislodging it). By selecting the appropriate setting inside the strobe, your camera’s pre-flash (used for red eye reduction) triggers the strobe to fire at precisely the right moment, flooding your subjects in beautiful white-light for clear, crisp photos. The best part about the unit is that there is a variable knob that allows for miniscule adjustments of the strength of the flash given off by the SL960D. I find that I’m usually somewhere between minimum and 1/3 power while shooting in the relatively murky waters of the Pacific Northwest, though I can imagine the fun one would have at full strength in the clear tropical waters.
The arm that the unit is affixed to is obediently flexible, and can be manipulated into a great many positions for optimal placement and direction. You should be aware though, that you won’t be able to get into any small crevices with the this strobe (or any other), which took a little getting used to.
On the negative side (pardon the pun), the SeaLife strobe has the unfortunate condition of being extremely positively buoyant. I found this to be of supreme irritation on my first dives with the strobe. This is the result of two factors: the inside of the strobe’s housing creates quite a large negative space (void), and the neoprene sleeve that covers the arm, though nice for holding onto, floats as all neoprene does. This problem can be remedied, thankfully, with a little ingenuity. I am not a very mechanically-inclined person, but I went to the hardware store and bought a number of non-magnetic washers and wrapped them in electrical tape (that stuff sure is handy!) and stuffed them into the housing. It looks like Frankenstein in there, but it does the job for the most part. I had a friend recommend that I should wrap the arm in ‘pencil weights’ used for fishing, which I’ll do eventually. Right now it’s bearable, though the unit is still quite like a cork above about 15fsw.
Also, when using the strobe, please use the provided diffuser, if any, that came with your housing. If you don’t, you’ll get a nasty shadow from the lens port of your housing in the opposite corner of the photo you’re shooting. This can also be remedied by taping around the internal flash, but it’s a lot easier to use what you’ve already got.
The battery life on this unit is nothing short of amazing. I can go weeks on end without a recharge, as long as I remember to power the strobe off when I’m done using it. The SL960D is rugged and has protective materials where needed. SeaLife provides a handy carrying case that ends up storing all your odds and ends for diving. Though SeaLife says the range is up to 8′, I am confident that the strobe can light up subjects at a greater distance. I highly recommend giving the SL960D a shot prior to diving into a more expensive unit. I picked mine up for a very reasonable deal through Underwater Sports, and now I know what to look for should I decide to go to a pricier model one of these days. I imagine that they’ll have these and other SeaLife external flashes for a steal at the upcoming Diver’s Fair.
Available Accessory: SeaLife SL968 Flash Diffuser
Update: As luck would have it, just after publishing this article I had a problem arise with the SeaLife strobe. After about thirtysome dives with it, the optical sensor is not picking up the signal from the fiber optic cable properly. The strobe still fires fine when manually triggered and I can visually see the flash being propagated through the cable. I’m going to send it in for warranty service and I’ll update this entry once I get word back from the manufacturer.
Update 2: I received the strobe back from SeaLife, repaired and fully functional in about 3 weeks. There was no cost associated with the warranty service through Underwater Sports, an authorized dealer, and they even sent it back with some velcro ties for the optical cable.