LIGHT MB SUB PHOTON LAMP

Michael then extolled the virtues of lithium-manganese batteries over "inferior" lithium and nickel-metal hydride alternatives, but he had not realised that he was trespassing in an area of diving religion, and had dared to criticise something already deemed perfect by a certain diving group's prophet.
Putting this to one side, I invited Michael to send me an example of one of his lamps for possible review in this magazine, which he did.
He sent me his high-output LED lamp in two forms. You can either use it as a hand lamp, the Photon, in which case it is almost compact enough to fit into a BC pocket, or in conjunction with a much larger battery-pack and umbilical connection, in which case its name changes to LED-Cave.
This product and its accessories are made to exacting Teutonic engineering standards.
There is nothing mass-produced about them - each piece looks as if Michael crafted it on his own lathe.
The manufacturer has so much confidence in his product that he offers a two-tier guarantee to all parts (including the battery), except for the LED itself.
Taking the lamp-head from the torch handle that holds the smaller of the battery-packs requires a lot of unscrewing, because Michael hasn't skimped on the threads.
Watertightness is assured by two well-spaced O-rings. This lamp-head can be used in conjunction with a similarly threaded male part that is permanently wired to a large battery canister instead.
A strongly engineered Goodman handle can be employed, or you can use a novel mount (translated from the German as "clip with grip") that I assume gets strapped to a forearm.
Another option is simply to stuff the long part of the mount up the sleeve of a snugly fitting wetsuit to give you hands-free operation.
I did notice, however, that the black anodising of the aluminium parts has a tendency to become damaged easily if knocked, and the first lamp sent to me had been in the care of a well-known British technical diving instructor and looked very much the worse for wear.
Michael sent me a new one for photography. He sells them direct from Germany, so prices reflect the exchange rate at the time of writing.

Light Source
The lamp-head employs a single Osram Ostar high-output LED. If I'm not mistaken, it's the first time I've encountered this light source in a diving lamp. It's quite odd-looking. It doesn't even look like a bulb, but it is so bright that it hurt my eyes while I was familiarising myself with the lamp.
It is said to knock out around 1000 lumens, which is about equivalent to a conventional 12V 50W halogen/tungsten bulb. That's very bright!

Power Source
Michael employs 12V lithium-manganese batteries in his lamps. The small torch version will give an hour's burntime at full power, plus half-an-hour's emergency lighting.
A finely engraved outer surface to the battery container affords a good grip.
The canister light for the Cave-LED has a burntime of six hours at full power, plus three hours of emergency lighting. The latter is also a method of
protecting the lamp's battery against damaging total discharge.
The canister battery is mounted by passing a tank camband through a piece of webbing secured by two familiar stainless-steel rubber-covered Jubilee clips, or it can be quick-mounted onto a tank bracket provided.
Naturally, you can also clip it to suitably positioned D-rings on a BC, using piston clips.
Charging is done via an intelligent charger and through the same fixed RCA connector that joins the lamp to the battery.
Depending on the sequence in which you connect battery and charger, it will begin recharging only if battery power is down at least 20%, or you can charge the battery at any state of charge. An indicator light on the charger shows either red or green.
Michael tells us that lithium-manganese batteries are perfect for use in diving lamps because they have high efficiency at low temperatures, suffer no memory effect from charging when partially charged, need no electronic security, offer long-life cycles at high capacities, and may be charged in gas-tight enclosures without ill effects.
The last is the reason why this lamp's battery-packs have no over-pressure relief valve for off-venting gases produced during use.

Switching
Now we get to the clever engineering part. Each handle supplied by Michael, whether it is the Goodman handle, the "clip with grip" or the simple switching ring, simply snaps onto the part that has been milled out on the lamp-head to take it.
Each of these has, built into the inner circumference, a small ball-bearing to ensure easy rotation around the barrel of the lamp, and a magnet that operates the in-built magnetic switch.
This switch has three positions that equate to off/reduced output/full power.
Putting the handle on the "wrong" way round affords security against accidental switching during transport.

Beam
The main part of the beam produces a 10° cone of light that gives a hotspot similar to those lamps that use three or four LEDs to the same effect.
Frankly, you would not want a lamp brighter than this. It turns a night dive into a day dive, and injudicious use can cause the temporary loss of vision of all the divers around you. It has a wide peripheral beam, too.
One could be forgiven for thinking that this lamp had an HID light source rather than an LED. You can certainly make the fish put their Raybans on.
Although I'm told that it's OK to use in air, the front of the lamp got distinctly hot after only a few minutes.
It's not cheap, but if you want something extra-special, this could be it!

COMPARABLE LIGHTS TO CONSIDER:
GreenForce TriStar Max (F2 battery), £520
Halcyon Explorer HID, £875

SPECS
PRICE Photon with bag £372 approx. LED-Cave with Goodman handle £593 approx. Includes charger, add VAT and carriage.
BATTERIES Rechargeable 12.6V lithium-manganese (1.6 or 9.6 Ah)
BURNTIME 60/90min or 6/9hr
EXTRAS Goodman handle, battery bracket, clip with grip.
WEIGHT 485g (Photon) or 1.5kg (Cave LED)
DEPTH-RATING 200m
CONTACT www.mb-sub.com
DIVER GUIDE