Question

In: Physics

3. A camera lens has a focal length of 50 mm, and a diameter of 30...

3. A camera lens has a focal length of 50 mm, and a diameter of 30 mm. If the diaphragm opening (F number) is 5.6. a. Explain the diffraction pattern (FranhouterFa by a circle gap with a diameter D! B. If blue light (450 nm is dropped on the lens, determine the size of the light spot at the focus point! C.) If two adjacent objects are located 10 meters in front of the camera, determine the smallest distance between two objects that can still be seen separately by 1 camera!

Solutions

Expert Solution

lens focal length f = 50mm

aperture F - number f/b = 5.6

aperture dia b = 50 mm/5.6 = 8.93 mm

When light is passed through a circular whole, light is diffracted by the whole. Light from the edges of the circular whole interferes and form alternate bright and dark rigs on the screen at a distance b >> D

radius of the first dark ring R = 1.22 D/b

If the light transmitted by the hole is converged a by a converging lens of focal length f

a bright spot is formed at the focus, of radius

R = 1.22 f/b = 1.22* 450E-9 * 50/8.9 = 3.08E-6 m

B) When light of 450 nm falls on the lens, diameter of the lens itself acts as the aperture and a bright spot is formed at the focus for a distance object. radius of the bright disc

R = 1.22 f/d = 1.22*450E-9 * 50/30 = 9.15E-7 m

C) Object distance 10 m large compared to focus. image formed at focus

radius of the disc = 9.15 E-7 m = 9.15E-4 mm

magnification = v/u = 50E-3/10 = 5.0E-3

if the two objects are seperted by x , then the image distance is

x*5E-3 > 2*9.15E-7 m , so that the two object images are well seperated

x > 3.66 E-4 m = 0.366 mm


Related Solutions

A camera lens has a focal length of 224.0 mm, an aperture diameter of 14 mm,...
A camera lens has a focal length of 224.0 mm, an aperture diameter of 14 mm, and the shutter speed is set to 1/10 s. What f-number setting would be required in order that the same camera sensor receive the same light intensity (brightness) if the shutter speed is now set to 1/40 s?
A camera lens has a focal length of 100 mm (thick lens). The photographer first adjusts...
A camera lens has a focal length of 100 mm (thick lens). The photographer first adjusts the location of the lens to look at an object very far away (infinite distance). Then he tries to take a picture of a person 2 meters away from the lens. How is he going to adjust (move) the lens relative to its original position? What is the distance of the adjustment?
a. A camera has a lens with a focal length of 0.032 m. The camera is...
a. A camera has a lens with a focal length of 0.032 m. The camera is set to an f-number of 5.6. The shutter speed (the amount of time during which the aperture is open to expose the film) is set to 0.35 s. What is the diameter of the camera's aperture? b. If the camera is focused on an object that is 0.39 m away from the lens, how far is the film behind the lens? c. If the...
A common zoom lens for a digital camera covers a focal length range of 18 mm...
A common zoom lens for a digital camera covers a focal length range of 18 mm to 200 mm. For the purposes of this problem, treat the lens as a thin lens. If the lens is zoomed out to 200 mm and is focused on a petroglyph that is 15.0 m away and 38 cm wide, (a) how far is the lens from the photosensor array of the camera and (b) how wide is the image of the petroglyph on...
A simple camera telephoto lens consists of two lenses. The objective lens has a focal length...
A simple camera telephoto lens consists of two lenses. The objective lens has a focal length f1 = 38.7 cm . Precisely 36.3 cm behind this lens is a concave lens with a focal length f2 = -10.0 cm . The object to be photographed is 3.97 m in front of the objective lens How far behind the concave lens should the film be placed? What is the linear magnification of this lens combination?
A microscope has an objective lens with a focal length of 16.22 mm and an eyepiece...
A microscope has an objective lens with a focal length of 16.22 mm and an eyepiece with a focal length of 9.28 mm. With the length of the barrel set at 31.0 cm, the diameter of a red blood cell's image subtends an angle of 1.43 mrad with the eye. If the final image distance is 31.0 cm from the eyepiece, what is the actual diameter of the red blood cell?
An 90mm focal-length lens is used to focus an image on the film of a camera....
An 90mm focal-length lens is used to focus an image on the film of a camera. The maximum distance allowed between the lens and the film plane is 130mm . A. How far ahead of the film should the lens be if the object to be photographed is 2.9 m away? B. How far ahead of the film should the lens be if the object to be photographed is 1.1 m away? C. What is the closest object this lens...
A camera lens has a power of +1.75D. If the diameter of the lens is 5.7...
A camera lens has a power of +1.75D. If the diameter of the lens is 5.7 cm, what is the f-stop of the lens? Does a single-lens camera produce a real or virtual image? Explain? A farsighted person has a near point of 38 cm. She holds her book at 25 cm to read, what is the focal length and power of the lens necessary for her to read? An electron travels at a velocity of 7.5x10^6 m/s through a...
An aerial camera has a 9½-inch square film format and a 6-inch focal length lens. What...
An aerial camera has a 9½-inch square film format and a 6-inch focal length lens. What must the flying height (in meter) be to obtain a scale of 1/2000? (Hint: 1 inch=2.54 cm)
A lens of focal length f1 = +20 cm has an object positioned 50 cm in...
A lens of focal length f1 = +20 cm has an object positioned 50 cm in front of it. A second lens of focal length f2= -15 cm is located 10 cm behind the first lens. a) Determine the two image positions for this combination of lenses. b) Is each image real or virtual, upright or inverted, and magnified or demagnified?
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT