When it comes to putting together your underwater photography and/or videography setup, choosing your strobe or video light arms and a tray might not be a priority. You're probably focused on selecting a camera, lenses, and a good set of strobes or video lights. So, your strobe arms and tray are probably a second thought.
Arms and trays may be one of the most underappreciated pieces of underwater photography and videography equipment, but they are critical for successfully lighting your images. In this guide, we break down the different types of arms and trays available, and lay out some suggestions for finding out what configuration is right for you.
So let's explain what you need to know so that you can make the right choice for you.
Lets start with a short explanation about what is the difference is between flex arms or ball and joint arms.
These are plastic segmented arms, with a strong resemblance to a human spinal cord. They are a ball and socket assembly with just enough friction to create an arm that offers unlimited positioning that stays in position.
Loc-Line (left) vs Chinese (right) Flex ArmThere are two very popular types in the market, one is made by Loc-Line®, of which there are plenty of copies. The Lok-Line system was conceived as a coolant delivery system for machinery, but is now used for many other applications, e,g, dive flex arms. The other type is a Chinese made flex arm shaped differently.
Although traditionally used for underwater videography, flexible arms are making a push into the photo market. The main argument is the versatility and ease of use of these arms. There's no need to tighten and loosen clamps when you want to reposition strobes. However, some feel that flexible arms don't hold up in rough conditions.
1/2-inch diameter Loc-Line is normally used, but some divers prefer 3/4-inch diameter Loc-Line with bigger, heavier video lights.
Advantages: Versatile, easy to use, and can be turned into an impromptu handle for your camera.
Disadvantages: Not meant for strong currents, and might not be sturdy enough for larger, pro-level strobes and video lights.
What to Look For: When choosing flexible arms, make sure to look for those that are as sturdy as they are flexible. They will hold up better in rough conditions.
Aluminium, Carbon Fibre and Float ArmsBall and joint arms resemble the human arms. They consist of aluminum segments with a ball at each end and the segments connect to one another by clamps that hold the 2 balls together. The balls are typically one inch in diameter. Some B&J arms have O-rings on their balls to tighten the grip and others don't. Many adapters and modifications are available for these arms such as YS to Ball mounts, Buoyancy Segments, Triple Clamp, Clamps with an extension or D-ring.
Ball and Joint Arms are by far the most common types of arms, and are made by dozens of manufacturers. They typically come in standard lengths of 5 inches, 8 inches and 12 inches.
Advantages: Most common, many options, and relatively inexpensive. Are available with buoyancy options.
Disadvantages: Can be hard to manoeuver.
What to Look For: Although the market is flooded with traditional ball and joint arms, they aren't all created equal. Look for those with lightweight but sturdy construction from materials like aircraft grade aluminium.
The first factor to consider is price. An average Flex Arm costs less than $75 whereas an average B&J arm of a similar length would cost about $200.
The second factor is travel weight. A B&J arm, being made of aluminium, weighs at least two or even three times more than a flex arm.
Now, let's ignore the above two factors and consider the difference in usability, functionality and durability.
Durability — The aluminum B&J arms are naturally more durable due to the fact that Aluminium is a strong material and is not affected from water, dirt or shocks. Flex arms get dirt and sand inside which causes them to become more stiff, they can break in certain situations and can also lose their stiffness over time causing them not to hold the weight of the light.
Functionality — Flex arms cannot be too long, because if they are, they won't hold the weight of the light. Flex arms also in most cases cannot hold the weight of the light above water and are only aimed to hold the weight underwater. This can make carrying the package on the boat more difficult. A flex arm can generally be up to 35 cm (14 inch) in length, more than that will be problematic and frankly, shorter is slightly better.
Why would you need long arms underwater? Well the main reason would be to prevent backscatter by getting better angles of light on your subject.
It almost impossible to mount anything in the middle of the flex arm as opposed to ball and joint arms. Things you want to mount are focus lights, lens holders, dive lights and more.
Usability — Flex arms are in many cases easier to use. They don't require opening and closing clamps and can easily be positioned to any position with only one hand which comes in quite handy underwater. However, they can make some squeaking noise which can scare away the fish and spoil the calm atmosphere in your video.
Travel — Flex arms bend and thus can be packed without disassembling.
Example Float Arm SetupUsing larger cameras can add significant weight, adding strain to your wrists and making it more difficult to maneuver underwater. Adding buoyancy through your arms will reduce the weight of your system underwater. This is advisable for systems that are heavily negative at depth — especially lens/port configurations where there is little airspace inside the housing to provide buoyancy.
There are three ways to add buoyancy through your arms. The first is to purchase B&J arms specifically designed to accept buoyancy floats. These will work with a wide range of buoyancy floats, varying from a tiny amount of lift to a significant amount of lift. The second option is to find buoyancy floats that fit standard strobe and light arms. These will have fewer options in terms of the amount of buoyancy provided by each float.
The final option is to use dedicated buoyancy arms. The idea is simple: a sealed pocket of air inside the metal arms provides buoyancy to your rig. The amount of lift provided differs between manufacturers, from just enough to make the arms buoyant, to enough lift for your entire rig. Some manufacturers even offer different buoyancy amounts for the same arm length. The downside to these arms is that they have a preset amount of buoyancy that cannot be adjusted to meet specific situations, and they can be rather bulky.
For an excellent guide to getting it right, please see "Best Buoyancy Solutions For Underwater Cameras" from our friends at Backscatter. We have the same, or equivalent, products available to everything they mention.
Example Ball ClampsUsing traditional ball and joint arms requires clamps. The right ball clamps are an important but often overlooked component of your arm setup. After all, you will likely be adjusting these ball clamps dozens (if not hundreds) of times on a single dive. Clamps, of course, are not required for flexible arm configurations.
With this in mind, the most important quality for your ball clamp is an ergonomic design you find intuitive. Each tightening mechanism is shaped slightly different. Some prefer a round wheel, while others like the flattened, sometimes S-shaped control.
Keep in mind that clamps are workhorses for ball and joint arm setups, and will take a beating even with the best care. For this reason, we recommend spending more on clamps from the higher quality manufacturers. Regardless of this, make sure to soak in fresh water after use to avoid rust on the screw mechanism or springs.
Most photographers use dual ball joint clamps, meaning a clamp that accepts two arms. However, some photographers like the new triple clamps, as they allow you to attach two arms, plus the addition of a focus light or GoPro.
Strobe and light arms come in a variety of lengths, making it possible to customise your setup to suit specific needs or conditions. There are no "correct" configurations, but there are some limits. For example, you should have a maximum length of a single flex arm of 18 inches, as the arms will be unstable at greater lengths. Here are some other recommendations based on shooting situations:
If you don't want to purchase all sorts of arm lengths and are looking for the most versatile setup, consider a configuration of 5 + 8 inches (per strobe/light), with the shorter length mounted to the strobe/light and longer one to the housing/tray. This offers a good working length for the strobes/lights for macro, super macro, and close-focus wide angle, while also allowing the camera to balance easily on the camera table.
Upgrade from Kit Arms: Oftentimes your first housing will come as a kit, along with a tray (or handles), arms, and clamps. While this is an attractive offer in terms of finance and simplicity, it should not be a permanent solution. The manufacturer probably specialises in housing design — arms and clamps, not so much. Invest in high quality arms from a company that specialises in these products. A good indicator is an extensive line with lots of options for different buyers.
Consider the Multi-functionality: Arm accessories are becoming increasingly common. If you might want to attach floatation devices, make sure they exist for the arms you choose. Also, for compact shooters, some arm manufacturers make wet lens "caddies" — a convenient way to store your wet lenses when not in use.
Consider Your Photography/Videography Focus: As you can see above and the diversity in arm types, there are a ton of configurations available. But that doesn't mean you need to invest in them all. Maybe you do macro photography, the vast majority with a heavy DSLR — short buoyancy arms might be the way to go. If you have a more buoyant system and like to take reefscapes in shallow water, consider long and lightweight ball and joint arms. Like to shoot both stills and video with your compact camera? Then flex arms might make the most sense.
The decision very much depends on what you want to mount on the arms. Assuming it's only a light on each arm, you would have to weigh the pluses and minuses.
If budget and travel weight is important then flex arms are the choice for you.
If you are looking for a versatile system and are willing to pay more for quality materials and extra length, then go for ball and joint arms.
Naturally, the better something is taken care of the longer it will last. Even though most ball and joint arms and clamps are virtually indestructible, treating them with respect will keep them in good working order.
After every dive, the best thing to do is thoroughly rinse everything in freshwater. If this is not possible, then keep the equipment wet by placing a wet towel over the equipment and refrain from drying out. What you don't want is saltwater drying on your gear, forming salt crystals that can cut and scratch O-rings, especially those you cannot service yourself.
You can wash your gear in hot, soapy water to remove the grit and grime that builds up once you get home. There are a couple of products on the market that help remove salt build-up.
Most of the inquiries we get about maintenance is how to clean the fuzzy salt build-up on parts such as clamps. To start, if possible, take as much of the part apart that you can by removing all stainless-steel nuts, bolts, and screws. Once apart, soak everything in a 50/50 water and vinegar solution for about 15-20 minutes.
Use a soft bristle brush like a toothbrush to clean the parts with. Don't forget to clean the inside of the T-knobs on the clamps. Sometimes it is necessary to repeat the process till everything is cleaned.
When done, dry and put back together. For the clamps add a small dab of silicone grease to the threads at the end of the bolt where the T-knob will be screwed on. Once finished they will be ready for your next trip.
Whenever you have two dissimilar metals in contact with each other, you will have electrolysis. This is what happens in the case of aluminium and stainless steel. The aluminium becomes oxidised and the nuts and bolts tend to freeze, making it difficult or impossible to remove them.
Sometimes wrapping the threads of screws and bolts with Teflon plumber's tape (found at your local hardware store), reduces electrolysis and removal of the screws, nuts, and bolts is much easier. If you are looking at the thread end, make a couple of turns with the Teflon tape in a clockwise direction while stretching it slightly.
The O-rings in the balls of the adapters will last one to two years if not left out in the hot sun all the time. They will crack, but this will not affect the clamping ability of the clamp. They should be changed when they are cracked, hardened or the arms do not seem to be holding as well as when new. It is easy to forget about the O-rings. We recommend replacing the O-rings every 2 years.
The O-rings can be difficult to remove and it's best if sharp, especially metal, objects are not involved in their removal. The best way is to squeeze with thumb and forefinger, pushing together while at the same time trying to move it to the side. This should give you a small amount of the O-ring to then roll over the ball.
You can purchase new O-rings from your dive shop, or maybe from your local hardware store. They are typically BUNA O-Ring, Size 2-209. To install the O-ring, stretch it over the ball and into the groove.
A tray and handle setup is the best way to keep your camera steady underwater. The wider the tray, the farther apart your hands, and the more stabile the camera. The tray and handle also provide the base for your arm and lighting setup.
Selfie sticks are not a good choice underwater because they wobble, especially when extended towards a subject. So leave those sticks at home unless you really want to capture a selfie perspective.
Yes, there are setups where you can mount handles and arms directly to your underwater housing. This usually happens with the larger DSLR underwater housings. However, typically the housing is fixed to a tray with one or two handles.
On cheaper setups, sometimes flex arms are used as the handle(s). We usually recommend dedicated handles with comfortable grips and the arms mounting to the top of the handles.
If you only have one light/strobe and are shooting stills rather than video, you can save some cash and bulk by not adding the second handle. For video having two handles adds real stability when shooting.
Some trays are fixed width, while others are adjustable width. This is an important consideration. The tray width required to take a GoPro action camera or Compact camera underwater housing is much less than required for your typical Mirrorless or DSLR housing.
There are a huge range of trays and handles on the market. We advocate getting a good quality, adjustable one. Down the line if you change camera and housing you will very likely still be able to use the tray.
Final Tray and Handle Tip: When assembling your tray and handles, use anti-seize lubricant to all threads going into aluminium.
Some underwater photographers like to mount a GoPro to the top of their underwater housing to record video while they simultaneously capture still images with their photo camera. These are our favouite ways to achieve this.
Hyperion Cold Shoe GoPro Mount Adaptor
RRP: $39, Our Price: $37.50, You Save $1.50 (4%).
This adapter enables you to mount a GoPro, or other action camera, onto the standard cold or hot shoe connector found on the top of most underwater camera housings. The downside of this arrangement is that you can only control the tilt to aim the GoPro.
This package combines three products to allow underwater photographers to mount a GoPro mount underwater housing onto the standard cold or hot shoe connector found on the top of most underwater camera housings. This package uses a 1-inch Ball Arm system to allow for swift re-positioning to get that perfect angle, no matter where you are or what you're doing.
Most underwater photographers and videographers find their preferred arm and tray configuration through trial and error. All of the advice above is a great place to start your search, but if you find your setup just isn't cutting it, don't be afraid to experiment with new types and lengths of strobe arms plus different trays and handles.
See Arms, Tray and Mounts for our full range.
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