Technical Information


Materials - A superior burner uses high quality quartz glass and a combination of mercury and rare earths in the gas chamber to produce pure white arc-light when ‘ignited’.

Burner Assembly - The assembly is vital in dictating a precise distance (arc gap) between the electrodes. Accurate alignment ensures that bulb fires up and can hold a steady arc. Poorly aligned burners create image flicker where the arc fails or jumps about. Then the burner cannot maintain an ideal operating temperature and the heat stressed quartz glass fails in an explosion.

Burner Assembly

Smart Lamp, electrodes well aligned
Cheap copy lamp - low precision

Smart Lamps select the best performing burners for reliability, stability and brightness, assembled using laser alignment.

Many Smart Lamps use the same burners used in
Original Manufacturer's (OEM) lamps.

Close Window


Shape - The geometric shape of the reflective outer housing must be identical to the manufacturer’s original lamp to ensure the correct light path. This ensures maximum light passes through the projector’s light engine for the brightest image.

Cheap copy lamps often use the wrong reflector meaning much of the light is lost as it isn’t collected and focused.

Coating - Needs to be the correct density and evenness of application to get the most visible light out of the bulb. Coatings also manage non visible light. Infrared (IR) light must be dissipated (often passing through the reflector coating) to prevent heat stressing the lamp, leading to an early failure. Over cool a lamp and the vaporized chemicals partially condense resulting in an instable light arc and a visible flicker.
At the other end of the light spectrum the reflector coating helps to prevent the escape of harmful Ultra Violet (UV) light to damage the light wheel or worse, shine on the audience.

Smart Lamps always use the identical shaped reflector
used in the OEM lamp and insist on high quality
reflector coatings.

Close Window


Assembly - The burner and reflector now need to undergo a precision assembly process to ensure the burner sits at the exact mathematical centre of the reflector. It must be perpendicular to the reflector’s centre of axis and be at the centre of curvature. The diagram below shows what cheap copy lamp manufacturers do:


Smart Lamp burner well aligned
Cheap copy lamp - low precision, reduced light output

The burner has not been set perpendicular as it was assembled by hand. The off-centre hotspot of light is not on the axis of the reflector. This results in a lower level of light being projected and a dull corner on the projected image.

Wattage - One of the hidden horrors of cheap copy lamps is the use of the wrong wattage bulb, for example, a 160 Watt bulb where it should be 200 Watt because it’s cheaper to make and less likely to fail. Brightness is already compromised but the projector’s electrical components now have to drive the bulb at a level they weren’t designed for, so shortening the life of the projector. Note – just because a copy bulb says ‘200 Watts’ on the reflector, it doesn’t mean a 200 watt burner was used. This is a common deception.

Smart Lamps always ensure each bulb selected is the correct wattage rated for the OEM lamp it replaces. Bulbs are assembled with laser alignment to ensure
maximum and even brightness.

Close Window

Connector and cable

If the correct connector is selected and installed the right way round there are rarely issues. Some cheap copy lamps do get this wrong, however. We have also seen poor practice where loose electrodes don't touch and sparking occurs.

Evidence of burning

A common cable issue is the use of a cable that is too thin, not insulated or the wrong length. Long cables can end up touching the extremely hot reflector, smoking until the cable shorts and the lamp fails.

Smart Lamps specify a cable type, route and length
to mimic the OEM lamp.

Close Window


Materials - The high temperatures found inside a working projector dictate the specification of raw materials used in cage construction. Too low a specification results in distortion, melting or even burning

Evidence of melting

Shape - cheap copy lamp manufacturers often make one cage design fit many projector models. The OEM specify the cage design for safety reasons, particularly to ensure the correct wattage lamp is installed in the projector.

Missing heat shields, locating lugs and air filters all expose the user to, at best inconvenience, at worst, fire risks and compromise of personal safety. Poor tolerances can result in lamps that can only be installed by brute force or are exceptionally loose so that they compromise the light path.

Smart Lamps not only ensure the cage material and design
is identical to the OEM lamp, but also ensure the
tolerances are very accurate to produce a
snug fitting lamp.

Close Window


Geometry - The right lens will focus the light beam through the projector’s light engine to maximise the light on the projection screen. Good lens geometry and a quality finish to the lens production contribute to this performance.

Material & Coatings - cheap lenses crack as they can’t withstand the heat they are required to operate under.

The heat build up is often due to poor coatings that, absorb or reflect IR light rather than discharging it safely through the back of the bulb. Similarly poor UV light control can destroy the projector colour wheel.

Smart Lamps carefully test the lenses and coatings used
to ensure they match the OEM specification.

Close Window
BBC News 25th May 2014 - Glasgow School of Arts, UK " Eyewitnesses said the fire appeared to have started when a projector exploded in the basement of the building on Renfrew Street in the city centre." Click here for the full story

Glass and mercury projector lamps operate at temperatures of 8,000 degrees Celsius and pressures of 200 atmospheres. Some require an ignition voltage of up to 20Kv. With this knowledge, cheap copy lamps start to sound rather worrying and their quality can have devastating consequences.

What is a lamp?

Lamp Components

Click on the headings above for more information.

Lens With UV Coating Cage Connector Cables Reflector Burner Bulb

All lamps contain a bulb and a cage with a connector, but that doesn't mean they are all the same. Very different practices in component selection, manufacturing techniques, assembly and testing start to explain why an Original Manufacturer's (OEM) lamp may be four times the price of a cheap copy lamp.

Our extensive experience as a lamp specialist means we can guarantee that a Smart Lamp uses quality components and practices to produce a premium compatible lamp.

Home Contact Information Terms & Conditions Privacy Policy © Just Lamps Limited E&OA