Parabolicreflector

If you are considering anti-reflective coating, check the grading scale offered by your optician. Some opticians offer a choice of "good," "better," and "best" (or a similar scale) with the "best" grade costing considerably more.

Hedaya MK, Elbahri M. Antireflective coatings: conventional stacking layers and ultrathin plasmonic metasurfaces: mini-review. Materials (Basel). 2016 Jun;9(6):497. doi:10.3390/ma9060497

Ellipsoidal light

The LED driver and dimming circuity are configured to accept control input through local controls and a communication interface that allows the luminaire to communicate with the DMX controller. Some products are RDM enabled to provide for improved control of the lights.

Ellipsoidal Spotlight

The high power LED module produces a high thermal load. In order to achieve their full potential for efficiency, performance and reliability, the critical junction temperature of the LEDs must be kept low. The housing of an ERS act as a heat sink and is typically constructed of die cast or extruded aluminum. The heat sink can comprise active cooling elements, such as fans, to increase the convection heat transfer coefficient, and hence drastically improve the lumen maintenance and color stability of the LEDs.

It's worth asking your optician about other available AR coatings. Manufacturers are constantly updating their materials and may offer superior products specifically designed for night driving, sports, or computer use.

The LED driver is integral to the luminaire. It usually operates over a wide input voltage range and adopts a two-stage design to provide tight regulation and control on the LED load for flicker-free lighting while providing a near unity power factor and a low total harmonic distortion (THD) over wide variations in line voltage.

In the past, anti-reflective coatings were either painted onto the lens or applied to the lens like a sticker. But that's not the case anymore. Today, anti-reflective coatings are fused onto the lens matrix, a technology first employed with high-powered telescopes and microscopes.

According to Vision Center, AR coating can add $20 to $150 to the cost of lenses. Insurance may cover some or all of that cost.

LED technology ushers in exceptional effectiveness in intensity manipulation since the current-driven LEDs are inherently controllable. This level of controllability also allows a multi-channel LED system to produce predictable colors through additive color mixing. The spectral power distribution (SPD) of LEDs, which corresponds to the color of a light source, can be engineered at the chip- or package-level by manipulating the bandgap of the semiconductor material and/or the composition of the phosphor down-converter.

An ERS combines an ellipsoidal shaped reflector with a lens system in front and has an optical gate at its focal point which enables the insertion of gobos (pattern plates) or irises to shape the beam of light. This stage light is unique in that it has two focal points. The light source is placed at the focal point of an ellipse. This second focal point position is the optical gate. The light produced from the light source is focused through the optical gate where the beam can be shaped with shutters, gobos, and/or irises. The shaped beam is then focused by the lens system. The lens system consists of one or two lenses, usually, 4.5, 6, 8, 10 or 12″ in diameter. The reflector and lens establish the focal length (the distance from the lens to the light source) which determines the size of beam produced.

Glare while driving at night is a common cause of accidents, especially for people with astigmatism. This eye disorder, which affects one in three Americans, can cause visual disturbances like halos and "whiteouts" with approaching headlights.

Ellipsoidalreflectorspotlight definition

Altalhi A, Khayyat W, Khojah O, Alsalmi M, Almarzouki H. Computer Vision Syndrome Among Health Sciences Students in Saudi Arabia: Prevalence and Risk Factors. Cureus. 2020 Feb 20;12(2):e7060. doi:10.7759/cureus.7060.

Yellow-tint glasses often touted to improve night driving vision, haven't been shown to be all that effective in clinical studies. Anti-reflective coating, on the other hand, does reduce glare and can improve nighttime driving performance.

Ellipsoidalreflectorspotlight diagram

Anti-reflective coating (also known as AR, no-glare, or glare-free coating) reduces glare by absorbing and redirecting reflected light. This allows more non-reflected light to pass through, leading to fewer visual disturbances. Unlike reflective lenses with mirror-like finishes, anti-reflective coatings are transparent with a very faint green or blue tint.

An ellipsoidal reflector spotlight (ERS) is a focusable luminaire capable of producing a narrow beam with hard edges. This is the most common instrument in use for highlighting certain areas of the stage, typically where the main action takes place. All ERS fixtures make use of lenses to produce highly controlled beams of light and incorporate shutters to shape the beam of light. The ability to create very crisp beams for a great visual impact with the absence of spill light and to accept slide-in gobos for pattern projection makes this fixture particularly useful to the stage lighting designer.

A typical ellipsoidal reflector spotlight includes a light source mounted either axially or radially with the base, a barrel that contains a lens or lens train, an, ellipsoidal reflector, a shutter assembly, a control panel with a display, and a set of brackets or an accessory holder on the end of the lens barrel that accept gel frames, a color changing unit or other accessories. Conventional ER spotlights incorporate high wattage tungsten-halogen or gas discharge lamps to deliver white light in a warm or cool tone, or produce colored light through subtractive color mixing. The profound energy, operation and application benefits enabled by LED lighting are facilitating a switchover to the new technology.

The coating is made up of carefully calibrated layers of metal oxides that are applied to the front and back of the lens and then irradiated with high-intensity ultraviolet (UV) light to enhance their light absorbency. This reduces reflected light and allows more non-reflected light to be transmitted through the lens.

Even so, a higher-end coating can be well worth your money. In addition to the benefits, these lenses tend to have better warranties and may be replaced at no charge if your lenses are scratched within a year.

Typically utilized in front-of-house positions (on the auditorium side of the proscenium), the ellipsoidal spotlight is usually the fixture of choice for accentuating features and specials. The accent light creates a focal pool of light that draws the audience’s attention to a performer or creates a visual interest. In America, an ERS is often referred to as a Leko, which is the brand name of a fixture created by Strand Lighting. In the U.K. the ERS is also called a profile spot because the beam can be shaped to the profile of an object.

Dimming of the LEDs is accomplished through pulse width modulation (PWM) which can provide a very precise output level over a full range from 100% to 0% and operate without color shift. Multi-channel dimmable LED drivers are used in tunable white lights and full-color systems such as RGB, RGBW, RGBWA and RGBAL lights. Each of the component LEDs of these lights requires individual, accurate current regulation and dimming control.

LEDs are semiconductor devices that are efficient in conversion from electrical to optical power and have a service life sufficiently longer to eliminate the need to replace the light source. These solid state light sources are also far more versatile than traditional light sources with regards to intensity, spectral and optical control. It is often desirable to implement accent lighting with a dimming functionality to provide fully, instantaneously variable light output.

Ellipsoidal Stage Light

Ellipsoidalreflectorlight

Hwang AD, Tuccar-Burak M, Peli E. Comparison of Pedestrian Detection With and Without Yellow-Lens Glasses During Simulated Night Driving With and Without Headlight Glare. JAMA Ophthalmol. 2019;137(10):1147–1153. doi:10.1001/jamaophthalmol.2019.2893

Ellipsoidal reflector spotlights are available in models of both fixed and variable focal lengths. A twin-lens system, in which two plano-convex lenses are installed “belly-to-belly”, makes it possible to achieve a variable focal length. This instrument is referred as a zoom ellipse. ER spotlights are sized by the lens diameter and the focal length of the lens in inches with 4 1/2 x 6, 6 x 9, 6 x 12, 6 x 16, and 6 x 22 being some commonly available sizes. They are also identified by their beam angle in degrees. These directional lights are available from 5° for very long throws to 90° for very short throws.

This article discusses how anti-reflective coating works, the pros and cons of anti-glare glasses, and how much it costs.

Anti-reflective coating on eyeglasses costs more, but it may be beneficial in specific situations, such as night driving and preventing eye strain from computer use. On the other hand, the lenses are easily scratched and may require replacement.

What are ellipsoidal lights used for

Tunable white LED luminaires that incorporate LEDs with different color temperatures offer the flexibility of adjusting the chromaticity coordinates in a wide range. Full-color lightings systems capable of creating any desired color across the defined color gamut at any level of saturation are becoming more and more popular. The multi-channel LED module used in these luminaires includes at least three LED primaries (red, green, and blue).

Vision problems caused by prolonged computer use are common. A 2020 study published in the journal Cureus reported that computer vision syndrome—a condition characterized by headache, itchy eyes, and temporary vision changes—was higher in eyeglass wearers and those who reported glare on their computer screens.

The American Optometric Association lists eyeglass lens coatings as one of the more useful solutions for computer vision syndrome.

Anti-reflective coating on eyeglasses is designed to reduce glare, making nighttime driving easier, and reducing eye strain from computer use. The coating is fused into the surface of the lens, giving it a very faint blue or green tinge. Despite their benefits, anti-glare glasses tend to scratch easily and would then need to be replaced.

While it's not an outright necessity, anti-reflective coating is something you may want to consider if you have symptoms of eye strain or spend a lot of time in front of a computer.

Vitale S, Ellwein L, Cotch MF, Ferris FL 3rd, Sperduto R. Prevalence of refractive error in the United States, 1999-2004. Arch Ophthalmol. 2008;126(8):1111-1119. doi:10.1001/archopht.126.8.1111

Anti-glare glasses also may help people who are sensitive to light while driving in the daytime or those boating in bright daylight. AR coatings are available for sunglasses too.

By Troy Bedinghaus, OD Troy L. Bedinghaus, OD, board-certified optometric physician, owns Lakewood Family Eye Care in Florida. He is an active member of the American Optometric Association.

An LED ERS that produces light in static white most often uses a chip-on-board (COB) LED array which provides high lumen output with superior beam uniformity, although discrete CSP and ceramic packages are also applicable. The white LEDs usually emit in tungsten-halogen (3200K) or daylight (5600K) colors. They are typically full-spectrum sources that deliver radiant power fairly broadly across the visible spectrum in order to faithfully reproduce color in illuminated objects.