Top Answer
User Avatar
Wiki User
Answered 2015-01-15 18:18:03

Because light can enter a lens from either side, a lens has a focal point on both sides. With mirrors, on the other hand, light only enters from one side, so they only have one focal point. the apex answer:

The centers of curvature of the two sides of the lens The material the lens is made from

User Avatar

Your Answer


Still have questions?

Related Questions

Do camera lenses have long focal points?

no dip sherlock

What are the types of lenses?

There are two types of lenses - fixed focal and zoom lenses.

Which focal lenses make the best Samsung digital camera?

18-55mm focal lenses are very good lenses for the Samsung digital camera. Other good lenses for the Samsung digital camera are the 28-90mm and 35mm focal lenses.

What kind of lens has a focal point?

Convex lenses have a focal point.

Lenses are engineered to have specific focal lengths Besides the curvature of the two sides of a lens what determines the focal length?

The material that the lens is made from.

What two things does every ellipse have?

An ellipse have two focal points.

How do you find the power of lenses using focal lengths?

Power (F)= 1/focal length (f) focal length f, is measured in meters the power, F, is in dioptres (D) In converging or convex lenses the power is positive In diverging or concave lenses, the power is negative :)

Do concave lenses have negative focal length?


What is parafocal?

parafocal lenses are zoom lenses that preserve the focal plane for every magnification factor.

How far apart are the two lenses of a refracting telescope?

They can be any distance apart depending on the focal length and magnification.

Does camera lenses have long or short focal points?

It depends upon the type of lens. Some are long and some are short. Others are variable such as a zoom lens.

Which two fixed points define the shape of a hyperbola?

the foci (2 focal points) and the distance between the vertices.

Do thick concave lenses have longer or shorter focal lengths than thin concave lenses?

It have a shorter focal length because there is more time for the light rays to come together

What are diverging and converging lenses?

Lenses enable individuals to view objects. A Converging lens has a positive focal length, which facilitates the convergence of the exiting rays. While, diverging lenses have a negative focal length, which facilitates the divergence of the exiting rays.

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.

Do thick convex lenses have longer or shorter focal lengths than thin convex lenses?

As a thicker lens has more material to do bend the light further it it would have a shorter focal length

In what pattern do the planets of our solar system travel around the sun?

In elipses. The Sun is at one of the focal points of the elipse.In elipses. The Sun is at one of the focal points of the elipse.In elipses. The Sun is at one of the focal points of the elipse.In elipses. The Sun is at one of the focal points of the elipse.

Do camera lenses typically have very long focal points?

We're going to assume that you mean "focal lengths".Camera lenses don't typically have very long focal lengths. The lenses with verylong focal lengths are the ones you see that look like a big tapered piece of pipesticking out on the front of the camera. Those are the extreme 'telephoto' lenses ...designed to blow up magnify (sorry) small objects in the distance. It's nearly impossibleto hand-hold the camera steady enough with such a lens, and you almost always seethem used with the camera mounted on a tripod for stability.Here's a somewhat-related fascinating and useful factoid:One focal length on the film = one radian (57.3 degrees) in the scene

How many types of spectacles lenses are available in market?

1:Single Vision Lenses 2:Multi focal Lenses 3:Bifocal Lenses 4:Progressive lenses Source Vision Express India

Why do convex lenses have shorter focal lengths than thin convex lenses?

The convex lenses are converging lens so when the curvature of the lens increases the focal length will decrease which helps when looking up close. A thin convex lens is for seeing things from a distant.

How you can find focal length of plane?

Are you sure about this? In my book, the only things to have focal lengths are lenses and other optical imaging systems.

What is the length of a telescope in normal adjustment?

At normal adjustment, the distance between the two lenses is equal to the sum of the focal lengths of each lens.

What is a sentence with the word focal?

Wide-angle lenses have a short focal length. The focal character of my short story is a ten-year-old boy.

Two lenses one of focal length plus 20cm and another of focal length -15cm are placed in contact What is the focal length nature and power of combination?

1) Simply, changing to diopters (inverse of focal length in meters), D1=5 and D2=-6.666... , then their difference is -1.666... which corresponds to F=-0.6m or -60cm.2) Using formula for two lenses: 1/F = 1/F1 + 1/F2 - d/(F1 * F2), where d = distance between lenses (here equal to zero), 1/F = 1/20 - 1/15 = -1/60; so F=-60 (cm).

If Jane is myopic. Will she need concave or convex lenses explain?

Concave. With myopia, the focal point of the eye is in front of the retina. Concave lenses increase the distance of the focal point so that it lies on the surface of the retina.