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Why do astronomers use as few lenses as possible in their telescopes?
Each lens absorbs some light, making the telescope weaker. I suppose each lens could also introduce certain abberations.
Why does a reflecting telescope have no chromatic aberration?
There's no aberration with the main MIRROR of the telescope, because light doesn't go through the mirror. A reflecting telescope will have SOME chromatic aberration, because every reflecting telescope has at least one refracting lens; the eyepiece. Light goes THROUGH that lens, and light passing through the glass lens will generate some chromatic aberration.
What causes chromatic aberration in the objective lens of a telescope?
The most chromatic aberration would occur with a single-lens refractor. However, today most telescopes employ at least two lenses, called achromats. These still incur significant chromatic aberration if the telescope has a short focal length to aperture ratio, called focal ratio. An easy way to determine if the telescope will have significant chromatic aberration is to divide the focal ratio of the telescope by the diameter of the lens in inches. A value of 5 or higher indicates minimal chromatic aberration; 3 to 5 is moderate aberration, and 3 and under is significant chromatic aberration. However, chromatic aberration is generally only obvious on bright stars or planets.
What is achromatic lens and what is its relation to power and dispersive power?
An achromatic lens is one without chromatic distortion (gives no colour fringing). The achromatism has no direct relation to power.
What are oil immersion objective lens for?
because the oil have a refractive index near the glass one so we can work at high power without lossing any details by eliminating the air gap between the the specimen and the objective lens >>>> a.sh (iug)
Who invented chromatic lens?
the person who invented the chromatic lens
Why are there Rings around edges of 1.67 hi index lens?
Its called Chromatic aberration. You must have a large RX. Try asking for a lens that is Atoric. Anti-reflective coatings will help this issue.
What is the difference between high index and polycarbonate lenses?
High-index lenses are an alternative choice to standard, plastic eyeglass lenses. Although high-index lenses are more expensive than plastic lenses, they can reduce the thickness and weight of an eyeglass lens, particularly for individuals with a strong prescription. High-index lenses are able to bend light to a stronger degree than a lens with a lower index, therefore the higher the index of the lens the less material needed to achieve a given prescription. High index lenses are categorized according to how strongly they bend light. The higher the index, 1.53 to 1.74 for high-index lenses, the better the lens is at bending light. High index lenses are 20 percent to 65 percent thinner than standard plastic lenses. In general, the stronger the prescription, the greater the difference in thickness between standard plastic and high-index plastic. A reduction in lens thickness and weight will occur in high-index lenses for prescriptions stronger than +2.00 or -2.50. Weaker prescriptions are not thinner than standard lenses when made with high-index materials. Polycarbonate lenses offer the same aesthetic benefits as high-index lenses, but polycarbonate lenses scratch easier, are difficult to coat or tint and are more likely to create distortions in colors and vision.
Why do astronomers use as few lenses as possible in their telescopes?
Each lens absorbs some light, making the telescope weaker. I suppose each lens could also introduce certain abberations.
Why does a reflecting telescope have no chromatic aberration?
There's no aberration with the main MIRROR of the telescope, because light doesn't go through the mirror. A reflecting telescope will have SOME chromatic aberration, because every reflecting telescope has at least one refracting lens; the eyepiece. Light goes THROUGH that lens, and light passing through the glass lens will generate some chromatic aberration.
Why do thick lenss show chromatic aberration but thin lenss do not?
because thick lenses have small focal length . this causes chromatic aberration. hence it can be minimised by increacing the focal length of lens or by using thin lenses which have high focal length.
What is the relationship between radius of the lens and refractive index?
None. The radius of the lens depends on its shape, the refractive index depends on the material that the lens is made from.
Who was so bothered with chromatic abberation?
Newton was bothered and developed a reflection telescope lens.
Who make better high index progressive lens Essilor or Zeiss?
Zeiss, quality product at reasonable price
What causes chromatic aberration in the objective lens of a telescope?
The most chromatic aberration would occur with a single-lens refractor. However, today most telescopes employ at least two lenses, called achromats. These still incur significant chromatic aberration if the telescope has a short focal length to aperture ratio, called focal ratio. An easy way to determine if the telescope will have significant chromatic aberration is to divide the focal ratio of the telescope by the diameter of the lens in inches. A value of 5 or higher indicates minimal chromatic aberration; 3 to 5 is moderate aberration, and 3 and under is significant chromatic aberration. However, chromatic aberration is generally only obvious on bright stars or planets.
Is microscopic lens corrected for chromatic aberrations?
Not all microscopic lenses are corrected for chromatic aberrations. Many times they will be for use in some places like laboratories and similar.
Will the focal length of glass lens change when dipped in liquid of refractive index equal to glass?
Everything a lens does is the result of the change of refractive index at its surface.If the lens is surrounded by a medium with the same refractive index as the glass,then there is no refraction (bending) of light at the glass surface, and the lens is nolonger a lens. If you could find such a liquid, you might not even be able to see thatthere's a lens down there in it.
