Binoculars telescope ED glass
ED glass of binoculars telescope is a kind of optical glass with special dispersion characteristics or high refractive index. The light scattering after refraction is very small, so it can eliminate color difference (color edge) and has high color restoration. At the same time, due to the light convergence after refraction, the imaging sharpness is also relatively high.
Generally speaking, ed in the lens group, the larger the lens, the better, the more the better, can improve the color reduction, make the color more beautiful and more real.
In recent years, the use of a series of high refractive index and low dispersion glasses (mainly lanthanide rare earth glasses) can better improve the imaging quality and further improve the lens quality.
Through precise optical calculation, lens grinding, assembly and so on, it can focus three kinds of color light at the same point, increase the clarity and color restoration degree, eliminate color difference for multiple kinds of color light (more than two kinds) and pursue zero color difference. Most apos use ed to eliminate the secondary spectrum.
In short, the cost of low dispersion lenses is higher than that of ordinary lenses. Excellent telescopes often need to use some relatively high-performance glass, such as fluorite, lanthanide glass, etc. these materials are difficult to process, high cost, and worth several times or even dozens of times of common glass. Some optical structures can have inherent advantages. For example, the imaging effect of Paul's telescopes at the same level is generally better than that of rooftop telescopes of the same type. However, Paul's mirrors are larger in volume, heavier in weight than rooftop telescopes, and their optical axes are easy to tilt. In short, rooftop telescopes and Paul's telescopes have their own advantages. For primary users, ED is not very different from non ed. For high power telescopes or astronomical mirrors with long focal length, it is recommended to choose ed or apo. The chromatic aberration will be obvious at high power. Choosing them can reduce dispersion and improve imaging sharpness. In addition to ED glass, there are many materials and structural design that can improve the quality of the binoculars, spotting scope, riflescope and monocular telescope, such as coating and so on. The material cost and processing accuracy determine its price.
Contact Person: Mrs. Christina Yi