Ceramic Metal Halide Lamp
The ceramic discharge metal-halide (CDM) lamp, often referred to as Ceramic Metal Halide lamp (CMH) is a source of light that is a type of metal-halide lamp which is 10-20% more efficient than the traditional quartz metal halide and produces a superior color rendition (80-96 CRI).
Applications for these lamps include television and film making, shop lighting, digital photography, street lighting, architectural lighting and agricultural lighting including grow lights.
CMH lights were introduced in the 1980s, but with recent discoveries in horticulture research, it makes sense why many growers are utilizing this technology.
The CRI of CMH's is around 90-92, close to the spectrum you get from the sun.
A CMH's Color Rendering Index (CRI) rating is close to the sun. CRI is a measurement of how true colors stay when the light is set upon them. HPS grow lights are 20 - 30 (so it's all orange/yellow) while Metal Halides are 60 - 65 (a little bit of a blue tint). Once you turn on a CMH bulb at either 3,000k or 4,000k, you’ll notice a more natural looking light spectrum. No strong orange and yellow hues like an HPS bulb, or the bright white and subtle blues from a Metal Halide.