Manufacturer: General Electric Company
Model: Daylight 100W E27 "Lux Solaris"
Application: General lighting, daylight simulation
Wattage: 100W (101W measured value)
Diameter (max): 60mm (PS60 lamp shape)
Length: 100mm
Tube Length: --
Bulb/Tube material: Neodymium glass
Colour Temperature: Unknown - Daylight simulation
Peak output wavelength: N/A - Broadband emission
Total light output: 500Lm (5Lm/W)
Rated lifetime: 1000 Hours
Cap: E27
Operating voltage: 230V AC
Operating current: 410mA
Warmup/restrike time: None
Cost (original): 2.29 (January 2006 from Maplin Electronics)
Value (now): --
Place of manufacture: Hungary
Date of manufacture: Unknown - Code C5 on lamp crown
Current Status: Working
Notes: Incandescent lamps employing means to alter the colour temperature to bring it closer to that of natural daylight are nothing new.  In the States (and Europe I believe), GE have a range of daylight simulating incandescent lamps similar, if not identical to this one as part of a range called the "Reveal" series.  These never made their way into the UK however.  It would appear however, that GE have produced lamps of this type for the UK market, just without making it a part of a specific series of lamps.  I've never seen these for sale in general places like supermarkets or such.  This one was spotted in a Maplin Electronics store (When I was actually looking for something utterly unrelated). 

These lamps are mainly aimed at those looking to illuminate an area such as a workbench or utility room.  Popular uses are in desk lamps used by people working on craft projects, where the higher colour temperature tends to lead to reduced eyestrain.  The other common application is use in the houses of people who suffer from disorders related to the lack of daylight in the winter.

Different companies have gone about providing the colour temperature correction on this style of lamp in a number of ways.  The cheaper ones generally just going for a coloured lacquer on the outside of the bulb (which almost invariably ends up cracking or flaking off over time).  Other lamps try to provide a slightly higher colour temperature by running the filament at higher temperatures (especially in the case of halogen lamps), which does work to some extent.  However there is a limit to how hot you can run a filament, and generally, the higher the temperature, the shorter the lifetime is.  This is why incandescent photographic floodlamps tended to have lifetimes in the region of a hundred hours at most.  Osram recently (late 2004) released a series of colour corrected lamps called the Active range, this made use of an internal powder coating to increase the relative blue output of the lamp (actually it's attenuating the red/yellow output!) to create light of a more neutral colour.  I have not actually seen one of these lamps in person, but I believe that the colour correction there is relatively slight, unlike with "daylight" lamps such as this, where quite an extensive change in the colour of the produced light is created.

This lamp however provides this colour correction by actually using pale blue tinted glass (called Neodymium Glass).  The advantages of this are that the colour of the lamp will not fade as the lamp ages, and that it provides far greater consistency in the colour from lamp to lamp than any external coating can.  The downside of course is that it makes the production of the lamp somewhat more expensive, especially so as daylight colour lamps represent a relatively very small percentage of the total production volumes of incandescent lamps.

The light output from this lamp is a relatively cool white - I'd not say it's quite "daylight" white, but it's not far off.  (If you want proper 6400K daylight - fluorescent lamps are your answer).  There of course is a very, very big drawback to this type of lamp - they're horribly, horribly inefficient.  The problem is that the majority of the output from incandescent lamps is at the red end of the spectrum, decreasing in intensity as the wavelength gets shorter.  This means that filtering out significant amounts of the red output, as the blue glass of this lamp does, means that a significant amount of the total output of the lamp is filtered out.  Hence the output of this lamp being a meager 500Lm, rather than nearer the 1000Lm mark as you would expect from a 100W lamp.

 
Click Thumbnails for full size images.

Homepage


Lamp added to the Virtual Display Shelf on Tuesday 21st January 2006 at 20:33.

References: None (Lamp packaging excepted).