SWITZERLAND IS NOT NOTED FOR CHEAP CONSUMER GOODS, nor cheap anything else for that matter. The Swiss are famous for making wristwatches that everyone wants but few can afford. I have a sneaking feeling that it will be the same with the Keldan range of underwater lamps.
NiteRider underwater lamps are made in the USA. These units used to be quite familiar at dive sites in the UK, when they were actively marketed here, but that side of things then went quiet. Now NiteRider is back with a new top model with HID lamp and nickel-metal hydride (ni-mh) battery technology.
The Keldan Solaris is the Swiss companys entry-level model in an aluminium lantern format. It has a hi-tech compact HID bulb fuelled by a charge-any-way-any-time 14.4V ni-mh battery pack. This comes in a modular form and quickly plugs into the main unit without having to engage any screw threads. You could buy a second pack to have on charge while using the first, if you could afford it.
The NiteRider HID is the US companys costliest offering. Like all its siblings, it uses mostly plastic in its outer casings and comes in two main parts - a battery-pack and single lamp-head - linked by an umbilical lead. Its 10W beam is equivalent to around 40W of conventional tungsten light. A fully charged 13.2V ni-mh battery will provide around four hours of burntime.
The HID lamp of the Solaris can be run at two different brightness settings, 18W and 24W (equivalent to 45W and 65W of conventional tungsten), much brighter than the NiteRider HID but with commensurate burntimes of only 80 minutes or one hour.
The Solaris lamp has a handy concentrated beam with an angle of around 10 but comes with a push-on wide-angle beam-spreader which, the maker promises, makes it useful with a video camera. It can be run for unlimited time in air without damage by over-heating. I wouldnt risk that with the lamphead and plastic lens of the NiteRider HID.
The sophisticated electronics of the Keldan Solaris protect its expensive HID bulb from power surges or intermittent switching. When you first turn on the lamp, using the rotating collar around the anodised aluminium main barrel of the lamp, a set of four LEDs at the battery-pack flash at an ever-increasing frequency to signify that the HID is not yet at full brightness.
A five-step series of five little coloured LEDs is left to indicate the amount of charge remaining in the battery-pack. You dont even have to turn the light on to test all this. A test position on the switching collar allows you to check that everything works properly. Thats when the four white LEDs show steadily. Remaining battery charge is indicated by the five coloured LEDs.
The switching collar has a precise detent mechanism to prevent unwanted movement. It charges from flat in three hours.
Its any-voltage charger has an innovative system for exchanging modular international plug connectors. The battery-pack also has deep discharge protection when it automatically switches to a low light output, and protection from fast discharge caused by overload and with consequent overheating.
The NiteRider is charged fully within 3.3 hours using the any-voltage Micro-Brute fast charger in-line with its transformer. You need to unscrew an access port equipped with a sealing O-ring on the battery-pack to connect the charger. There is a fixed lanyard so that you cannot inadvertently drop it.
When you fire up the NiteRider, the lamp takes a while to get going. Like many other underwater lights equipped with HID lamps, it seemed a little crude compared to its swish Swiss competitor, even a little fragile. You have to turn it on and leave it on.
I found the Solaris simple to operate. Its slightly negative weight of about 0.5kg in water makes it convenient to use and, when I was not using it to light my way, I carried it with its welded aluminium handle passed through the webbing waist strap of my BC. There is a hole in the handle for a lanyard.

width=175NITERIDER The lamp-head can be mounted on your wrist for hands-free operation. Its cone of light has a typical HID blue tinge

NiteRider provides a variety of ways to carry its light conveniently. First, the not-so-big battery-pack clips either to your weightbelt or to the cummerbund of your BC, or even the camband to your tank. Its weight is almost irrelevant, because it replaces weight on your belt - I guessed around 0.5kg.
The lamp-head can be attached via a special mount to your wrist, leaving your hands free, or even by way of another mount, to your head. I suggest that this second method should be used only by solo divers or those with an already blind buddy, otherwise every time you look at him you will leave him bedazzled.
The NiteRider is turned on and off using a simple switch on the battery pack, protected by a locking-pin that drops into position when its off to prevent accidental use. I found this slightly difficult to manipulate with a thick glove on.
That said, you should switch this HID unit on when you hit the water and leave it on until back on the boat. If you need to separate battery-pack from lamp-head, the lead has a waterproof two-pin push/pull wet-connector. You can do this safely under water.
One disappointment with the Keldan Solaris was that, even with beam-spreader fitted, its beam was far too uneven for the decent video lighting promised. If I owned one, I think I would give the beam-spreader a quick dose of nail-varnish remover to etch it and give it a translucent effect with more diffusion.

The quality of the light of the Solaris, at 5200K, almost matches mid-day sunshine. This is unusual but it is more comfortable on the eyes. Most lamps with HID bulbs run at a much higher colour temperature which might penetrate water further but light things in a rather unsympathetic blueish light. This is true of the more typical 6000K HID light from the NiteRider.
Both gave very similar-shaped cones of light with about the same 10 angle to the central, bright part of the beams. Contrary to specifications on paper, my lightmeter revealed that the Keldan Solaris at full power was more than eight times as bright as the NiteRider. It really can turn a night dive into a day dive!
However, unless you are using the lamp with a camcorder this is almost irrelevant, as your eyes have the uncanny ability to adjust. Just dont go on a dive with someone using a Solaris if your light is puny by comparison.
Light quality and quantity aside, this is a choice between the convenience of the US mounted lamp-head and umbilical system versus the precision-made, high-tech approach of the Swiss.
As you might expect, neither comes cheap. The NiteRider HID will set you back around£600 with lamp-head and mounts. Of course, you can spot a Keldan Solaris owner long before he opens his dive bag. Hell be wearing a gold Rolex and his dive boat will be his own personal Riva. The Solaris costs around£700.
Keldan models with larger batteries and longer burntimes are available with umbilical models but cost even more. Check the websites for availability. You may have to order either make from outside the UK.

  • Keldan Solaris, www.keldan.ch; NiteRider HID, www.niterider.com