Skip to main content
Ch 34: Geometric Optics
Young & Freedman Calc - University Physics 14th Edition
Young & Freedman Calc14th EditionUniversity PhysicsISBN: 9780321973610Non è quello che usi tu?Cambia libro di testo
Capitolo 34, Problema 49a

A camera lens has a focal length of 180.0 mm and an aperture diameter of 16.36 mm. What is the ƒ-number of the lens?

Guida verificata passo dopo passo
1
Step 1: Understand the concept of the ƒ-number. The ƒ-number (or focal ratio) is a dimensionless quantity that describes the light-gathering ability of a lens. It is defined as the ratio of the focal length (f) to the aperture diameter (D). The formula is ƒ-number = f / D.
Step 2: Identify the given values from the problem. The focal length of the lens is f = 180.0 mm, and the aperture diameter is D = 16.36 mm.
Step 3: Substitute the given values into the formula for the ƒ-number. Using MathML, the formula can be expressed as: fD. Replace f with 180.0 mm and D with 16.36 mm.
Step 4: Perform the division to calculate the ƒ-number. Divide the focal length (180.0 mm) by the aperture diameter (16.36 mm). This will yield the ƒ-number.
Step 5: Interpret the result. The ƒ-number is a measure of how much light the lens can gather. A smaller ƒ-number indicates a larger aperture and more light-gathering ability, while a larger ƒ-number indicates a smaller aperture and less light-gathering ability.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
1m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Focal Length

Focal length is the distance from the lens to the point where light rays converge to form a sharp image. It is a critical parameter that determines the lens's magnification and field of view. A longer focal length results in higher magnification, while a shorter focal length provides a wider field of view.
Video consigliato:
Percorso guidato
10:54
Spinning on a string of variable length

Aperture Diameter

The aperture diameter refers to the size of the opening in the lens through which light passes. It affects the amount of light entering the camera and influences the depth of field in an image. A larger aperture allows more light, resulting in a shallower depth of field, while a smaller aperture reduces light and increases depth of field.
Video consigliato:
Percorso guidato
04:06
Continuity / Proportional Reasoning

ƒ-number (f-stop)

The ƒ-number, or f-stop, is a dimensionless number that represents the ratio of the lens's focal length to the diameter of the aperture. It indicates the lens's light-gathering ability; a lower ƒ-number means a larger aperture and more light, while a higher ƒ-number indicates a smaller aperture and less light. The ƒ-number is crucial for controlling exposure and depth of field in photography.
Video consigliato:
Percorso guidato
07:19
Moles & Avogadro's Number
Pratica correlata
Domanda del libro di testo

Contact lenses are placed right on the eyeball, so the distance from the eye to an object (or image) is the same as the distance from the lens to that object (or image). A certain person can see distant objects well, but his near point is 45.0 cm from his eyes instead of the usual 25.0 cm. Is this person nearsighted or farsighted?

1750
views
Domanda del libro di testo

Where is the near point of an eye for which a contact lens with a power of +2.75 diopters is prescribed?

1833
views
Domanda del libro di testo

BIO The Lens of the Eye. The crystalline lens of the human eye is a double-convex lens made of material having an index of refraction of 1.44 (although this varies). Its focal length in air is about 8.0 mm, which also varies. We shall assume that the radii of curvature of its two surfaces have the same magnitude. Find the radii of curvature of this lens.

535
views
Domanda del libro di testo

Zoom Lens. Consider the simple model of the zoom lens shown in Fig. 34.43a. The converging lens has focal length f1 = 12 cm, and the diverging lens has focal length f2 = -12 cm. The lenses are separated by 4 cm as shown in Fig. 34.43a. (a) For a distant object, where is the of the converging lens? (c) Where is the final image? Compare your answer to Fig. 34.43a.

1684
views
Domanda del libro di testo

You wish to project the image of a slide on a screen 9.00 m from the lens of a slide projector. If the dimensions of the picture on a 35 mm color slide are 24 mm ✖ 36 mm, what is the minimum size of the projector screen required to accommodate the image?

1832
views
Domanda del libro di testo

BIO Ordinary Glasses. Ordinary glasses are worn in front of the eye and usually 2.0 cm in front of the eyeball. Suppose that the person in Exercise 34.52 prefers ordinary glasses to contact lenses. What focal length lenses are needed to correct his vision, and what is their power in diopters?

1782
views