Optics: Illumination Angle
LEDs are extremely energy-efficient from an illumination efficacy standpoint, i.e., lumens per watt. Upwards of 95 percent of the light can be directed at the target area of illumination whereas a typical incandescent bulb may be only 60 percent effective.
In other words, a lot of the light produced by an incandescent bulb does not go to the intended target.
Incandescent bulbs require reflectors, louvers, and/or diffusers to compensate for unnecessary light.
Fluorescent bulbs are more energy-efficient than incandescents, but the ballast may consume up to 20 percent of the electrical energy going into the fixture.
Retrofitting LED technology in traditional luminaries is tricky because most fixtures are designed to overcome the limitations of traditional spherical light output.
Reflectors, cones, masks, shades and diffusers help bend, redirect, or shield the light emitted from incandescent, fluorescent and halogen sources, but it creates unnecessary physical barriers for implementing LED technology.
Designing specific forward-fit LED-based luminaries can produce several times foot-candles on a given area per watt than other traditional incandescent bulb technologies.
Because of the directional illumination skylt & dekor pattern that LEDs provide the light can be directed to the specific area that needs to be illuminated.
Optics: Light Color
Over the years, fluorescent bulb manufacturers had some challenges getting users to accept the white color produced by fluorescent technology.
Because of the limitations of phosphor technology, the fluorescent industry introduced subjective terms such as "cool white" or "warm white" to draw comparisons to incandescent white.
Not coincidentally, white LED manufacturers face the same challenges since white LED technology is based on phosphor energy.
To put things in quantitative perspective, LED manufactures have referred to Color Rendering Index (CRI) which is a measurement of a light source's ability to render colors accurately.
The higher the CRI, the more natural the colors appear, with natural sunlight having a CRI of 100. However, this may not be the best metric for comparing light sources.
Originally developed in 1964, this index is based on color models with broad spectral distributions. White LEDs are narrow-band sources. Color Temperature may be a more suitable tool for comparison because it is a less subjective measure, based on degrees Kelvin.
Presently there are several white emitters to choose from in the 3,200 degree-Kelvin and 5,500 degree-Kelving range.
No matter how the color is measured, LED manufactures have made great strides to match the warm white glow of an incandescent bulb with high-quality LEDs due to the tremendous demand for incandescent white tones.