The maximum resolution of the eye depends on the diameter of the opening of the pupil (a diffraction effect) and the size of the retinal cells. The size of the retinal cells (about 5.0 mm in diameter) limits the size of an object at the near point (25 cm) of the eye to a height of about 50 µm. (To get a reasonable estimate without having to go through complicated calculations, we shall ignore the effect of the fluid in the eye.) (a) Given that the diameter of the human pupil is about 2.0 mm, does the Rayleigh criterion allow us to resolve a 50 -µm -tall object at 25 cm from the eye with light of wavelength 550 nm? (b) According to the Rayleigh criterion, what is the shortest object we could resolve at the 25 cm near point with light of wavelength 550 nm? (c) What angle would the object in part (b) subtend at the eye? Express your answer in minutes 160 min = 1°2, and compare it with the experimental value of about 1 min. (d) Which effect is more important in limiting the resolution of our eyes: diffraction or the size of the retinal cells?
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- Diffraction due to a circular aperture is important in astronomy. Since a telescope has a circular aperture of finite size, stars are not imaged as points, but rather as diffraction patterns. Two distinct points are said to be just resolved (i.e., have the smallest separation for which you can confidently tell that there are two points instead of just one) when the center of one point's diffraction pattern is found in the first dark ring of the other point's diffraction pattern. This is called Rayleigh's criterion for resolvability. Consider a telescope with an aperture of diameter 1.02 m. Part D What is the angular radius 0₁ of the first dark ring for a point source being imaged by this telescope? Use 550 nanometers for the wavelength, since this is near the average for visible light. Express your answer in degrees, to three significant figures. xa — ΑΣΦ Xb 0₁ 5.39 10 = 7 √x x x <४ |X| Submit Previous Answers Request Answer ? X.10n X You have already submitted this answer. Enter a new…arrow_forwardA distant point source of light (like a star) emits light of wavelength 575 nm. When this light enters a camera whose lens has a focal length of 135 mm, the diffraction pattern formed on the camera’s detector has an Airy disk of radius 0.0112 mm. Find (a) the diameter of the lens aperture and (b) the f-number.arrow_forwardThe headlights of a pickup truck are 1.32 m apart. What is the greatest distance at which these headlights can be resolved as separate points of light on a photograph taken with a camera whose aperture has a diameter of 13.8 mm? (Take A = 504 nm.)arrow_forward
- Two stars have an angular separation of 8.50 ✕ 10−8 rad when viewed in the night sky from Earth. Determine the minimum diameter of a telescope's circular aperture if the two stars are to be angularly resolved at a wavelength of 625 nm.arrow_forwardThe resolution of the eye is ultimately limited by the pupil diameter. What is the smallest diameter spot the eye can produce on the retina if the pupil diameter is 2.41 mm? Assume light with a wavelength of λ = 550 nm. (Note: The distance from the pupil to the retina is 25.4 mm. In addition, the space between the pupil and the retina is filled with a fluid whose index of refraction is n = 1.336.)Hint: The size of the spot is twice the distance from the main axis to the first minimum.arrow_forwardA vehicle with headlights separated by 1.74 m approaches an observer holding an infrared detector sensitive to radiation of wavelength 885 nm. What aperture diameter is required in the detector if the two headlights are to be resolved at a distance of 25.0 km?arrow_forward
- A diffraction grating of diameter 1cm and 400 lines/mm is illuminated by white light at normal incidence. The diffracted light from second order is then focused by a camera lens of focal length f onto an electronic image detector, with the lens and detector aligned to the diffracted light at λ = 550 nm. - If the detector width is 2 cm, calculate the maximum value of f so that the whole wavelength region 400 nm to 700 nm is observed on the detector. Also, calculate the maximum detector pixel size in order that two wavelengths near 550 nm and separated by the minimum resolvable λ are separated by at least 2 pixels on the detector.arrow_forwardWhat is the resolving power of a microscope with a 5 mm diameter objective and f = 9 mm for light with a wavelength of 550 nm?arrow_forwardFlies have compound eyes with thousands of miniature lenses. The overall diameter of the eye is about 1 mm, but each lens is only about 20 μm in diameter and produces an individual image of a small region in the fly’s field of view. Compared to the resolving power of the human eye (in which the light-gathering region is about 16 mm across), the ability of a fly’s eye to resolve small details is (i) worse because the lenses are so small; (ii) worse because the eye as a whole is so small; (iii) better because the lenses are so small; (iv) better because the eye as a whole is so small; (v) about the same.arrow_forward
- The Hubble Space Telescope (HST) orbits Earth at an altitude of 613 km. It has an objective mirror that is 2.40 m in diameter. If the HST were to look down on Earth's surface (rather than up at the stars), what is the minimum separation of two objects that could be resolved using 549 nm light? [IVote: The HST is used only for astronomical work, but a (classified) number of similar telescopes are in orbit for spy purposes.]arrow_forwardA vehicle with headlights separated by 1.95 m approaches an observer holding an infrared detector sensitive to radiation of wavelength 885 nm. What aperture diameter is required in the detector if the two headlights are to be resolved at a distance of 26.0 km? mmarrow_forwardA vehicle with headlights separated by 1.71 m approaches an observer holding an infrared detector sensitive to radiation of wavelength 885 nm. What aperture diameter is required in the detector if the two headlights are to be resolved at a distance of 27.0 km?arrow_forward