In Europe, elliptical coated HPS lamps were traditionally used where the lamps were fitted inside mercury lanterns, so that the light distribution was not compromised by using an uncoated lamp. However, as the years went by, lanterns became purpose designed for clear tubular HPS, and so there was no longer the necessity to mimic elliptical coated mercury lamps for light distribution purposes. Furthermore, clear tubular HPS lamps in Europe are slightly more efficient at producing light than coated elliptical lamps. For example, comparing Philips 70w PiaPlus lamps, clear tubular produces 6000 lumens whilst coated elliptical produces 5600 lumens.
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