Umbilical video lights - where / how to mount battery canister?

Despite being new to underwater photography / videography I rather ambitiously bought a duel set of Bersub video lights of fleabay that are powered by a hefty sized battery canister (dry weight 1.7kg, diameter 80mm, length 200mm). The umbilical cables are no the wet type so can not ('should not' is probably a better description) be removed underwater.

I am using an S95 in an ikelite housing on a dual arm tray. As I see it have two options;

1. Mount canister on the camera, under the tray
2. Mount canister on myself, say on the waist strap

Given the relative size of the the idea of mounting the canister under the camera is not very appealing to me. The canister will be negatively buoyant so I would have to think about buoyancy arms or floats to make it manageable. On the other hand if I hang the canister on me then ditching the thing in case of an emergency becomes harder, also I foresee kitting up and entries taking more thought. If I waist mount like a traditional battery canister I would need to undo the waist strap and loosen my whole diving harness to take the camera off. Even in non emergency situations it would be nice to detach the canister more easily if say I am handing the camera rig up someone in a rhib.

Any advice on what to do would be greatly appreciated.

Hi Mikeal,

I guess you basically mention the two possible options :

1. mount the canister on the housing > make everything floating / neutral with buyoncy arms

2. mount the canister on the belt / strap > instal E/O cord - wet connectors

I dive option 2 for all the reasons you mention.

Additionally, using the E/O cords gives me also the flexibility to use the video canister for my primaire light and vica versa in case of a failure.

Gr, Stephan.

If the canister is not easily removable from yourself, perhaps the lightheads can be made easily removable from the camera rig? I agree that emergency dump-ability and everyday practicability means having the camera tied to yourself is not ideal.

I would mount it on the bottom of the camera, will provide some damping for any movements, due to more inertia.

I guess it depends on how big / heavy your rig is.

For Mikael both options could work as I understand the rig is not that big / heavy.

(For me it would be to heavy on land and too bulky underwater.)

Having recently invested in some ball joint style arms and new tray over the locline variant I had before I have now pulled the setup together as seen below:

This quite a clunky creation already and has reasonable amount of weight behind it even without the wet lens screwed on. The prospect of attaching the canister underneath I reckon is a No. I generally either shore dive or if I am lucky go out on a hard boat with lift. I would far rather have the canister secured on my hip then attached to something that is clipped on and swaying off my body.

My concern is predominately about the moving about out of the water and specifically entries and exists. With weight of small twinset already on me plus all the other cold water diving gear I am not the most agile. Across a rocking boat or across uneven shore entries I don't want to take a tumble as I would like both me and the camera to return in tact. Any advice greatly appreciated. Guess I should be glad I am not using a large DSLR system with ligths / strobes!

Personally I would mount the battery under your rig and add some buoyancy to the top.

Here are some pictures of a system I've developed which I hope are self-explanatory. It involves attaching a small buoyancy chamber (ie bucket) to the top of the rig in such a way that it can be moved forward, sideways, or to the rear to provide buoyancy exactly where required. Adding/releasing air from the bucket and adjusting its position allows you to have your unit neutrally buoyant and sitting straight and level, or alternatively at any angle you want, at any depth. Releasing all the air allows you to place your unit on the bottom, nice and steady for those closeup nudi shots.

It looks ugly, but it's cheap and it works!