Choosing a light source

There are number of different types of torch, lamp or lantern from small key-ring types up to full tent lamps.

Here we’ll discuss the various types, their pro’s and con’s.

Fuel

There are basically 3 ways of fuelling a light – electric cells, gas or liquid fuel. Obviously the safest, for several reasons, is the electric cell:

Ø  Lamps generally run cooler so less chance of injury.

Ø  No naked flame.

Ø  Generally do not leak causing potential fire and poison risks.

Another obvious advantage is that electric cells can safely be carried onboard an aircraft, whereas gas and liquid fuels cannot…

 

Electrically powered lights

Electrically powered lights come in a whole range of sizes and formats but basically rely on one of two means of being powered replaceable cells or rechargeable cells, and one of two light sources – wire filament bulbs or LED’s (Light Emitting Diode).

Obviously each type has its own advantages and disadvantages.

Ø  Bulbs

o   Advantages.

§  Cheap to buy.

§  Very light.

o   Disadvantages.

§  Easily damaged.

§  Can be heavy on power drain.

Ø  LEDs

o   Advantages.

§  Very long life.

§  Very low power drain.

§  Wide variety of colours available.

o   Disadvantages.

§  Can be expensive to replace.

Ø  Cells

o   Replaceable cells

These are basically ordinary batteries of the type that you would find in your watch, pocket radio etc. they may either be disposable or rechargeable. The former being cheaper to buy, the latter obviously saving money in the long run.

o   Rechargeable cells

These are basically ordinary batteries of the type that you would find in your watch, pocket radio etc. they may either be disposable or rechargeable. The former being cheaper to buy, the latter obviously saving money in the long run.

These may either be replaceable, like those mentioned above, or built into the device. They are recharged by placing into a charging unit, or if inbuilt, by connecting to a charging device  -  transformer plugged into the mains or cigarette lighter socket of a vehicle, or possibly via a solar panel.

 

Colours – modern LED’s come in a number of colours with 3 being the most common and useful.

Ø  White

o   Advantages.

§  The most common.

§  Cheapest.

§  Brightest.

§  Can be seen at long distances.

o   Disadvantages.

§  Destroys night vision.

Ø  Blue

o   Advantages.

§  Can be seen at long distances.

§  Doesn’t affect night vision as badly.

o   Disadvantages.

§  Slightly more expensive.

Ø  Red

o   Advantages.

§  Doesn’t affect night vision.

o   Disadvantages.

§  Slightly more expensive.

§  Can’t be seen at such distance

Now, let us move on to the various types of light, starting with the

Micro torch

These come in various guises including key-ring type varieties.

Whilst not particularly practical as a main torch, they do make an excellent emergency or back-up torch.

Very useful to keep in your survival kit.

They generally run of a ‘button cell’ of the type used in batteries and are often disposable.

They don’t have much of a range, nor beam width.

Mini torch

These basically small torches that normally run off small, standard batteries such as the AAA battery.

The most common type is the ‘mini-maglite’.

They are quite bright and have adjustable beams from near focus wide beam to far focus narrow beam.

Standard torches

These are the standard tyres of torches that are kept in the glove compartment of your car, or at home for use in power cuts.

They vary in size from twin AA maglite styles up to C and D cell types.

They may either be of a ‘baton’ style or the military right angle variety which runs off two D-cells.

This type is one of the best as the filter (kept in a section of the base) can be changed for the reasons stated above in the ‘Colours’, the unit has a spare bulb in the base unit and it also comes with a belt clip for hands free use.

Filters included normally include:

Ø  White

o   Dims the level of the light.

Ø  Red

o   Preserves night vision.

Ø  Blue

o   Does not affect night vision as badly as unfiltered light.

Ø  Green

o   As Blue.

Ø  Yellow

o   No real use…

Ø  Diffuser

o   Softens and broadens the beam as there is no beam focus facility.

It is possible to fir two filters at once to the filter clamp.

It also comes in a smaller version.

Gas and liquid fuel lights

This type of light is very similar, no matter what the fuel.

The light has a reservoir at the base and in the case of paraffin a wick that is adjusted and lit.

In the case of petrol and gas lamps, they also have a pressurised reservoir that feeds a mantle which glows to provide light.

The only drawback with this type of light is that the mantle becomes very brittle and fragile so spares must be carried.

The main drawbacks with these types of light are that aside from potential fire hazard due to the flame, and the fact that if the fuel leaks it can be poisonous, separate fuel must be carried and become dangerously hot to the touch and also the lamps give off quite a lot of heat – which in cold weather conditions can actually be an advantage…