answersLogoWhite

0

The power of a lens is the reciprocal of its focal length in meters. So, a lens with a focal length of 25 cm would have a power of +4 diopters (1/0.25 = 4).

User Avatar

AnswerBot

1y ago

What else can I help you with?

Related Questions

What is the difference between a thick convex lens and a thin convex lens?

A thick convex lens has a larger thickness and can bend light rays more than a thin convex lens. This results in a shorter focal length and stronger focusing ability for a thick convex lens compared to a thin convex lens.


A polygon whose sides all have the same length is said to be?

A regular polygon.


An object seen close up through a convex lens looks than it really is?

A convex lens is a mirror whose middle is larger than the top and bottom. A convex lens is more than two focal lengths. It is smaller and inverted between one and two focal lengths.


Does the photo in a 75-300 lens make the picture look like at 75 feet as it does at 300 feet?

No. My guess is that you have a zoom lens, whose focal length can be varied over the range of75 to 300 millimeters.The larger the focal length of the lens, the larger (closer) the objects in the picture appear.The handy, easy-to-remember rule that I use is: One focal length on the film (or CCD) depictsone radian in the scene (or sky).


What does mean the mm e.g. 18 -200 mm camera or 55-200 mm?

That number is the focal length of the camera's lens ... which focuses light from the scene to form an image on the 'film' or CCD inside the camera. The longer the focal length of the lens, the larger (nearer) the objects appear to be in the picture. (One radian of angle as seen by the lens ===> One focal length on the film.) On the cameras described in the question, the focal length is given as a range ... "from 18 to 200 mm", and "from 55 to 200 mm". Each of these is a "zoom" lens, whose focal length can be changed over the range, enabling the user to cause objects in the picture to appear somewhat nearer or farther away.


Can a convex lens behave as a concave lens?

No, a convex lens cannot behave as a concave lens because they have different shapes and properties. A convex lens converges light rays to a focal point, while a concave lens diverges light rays. They produce different effects on the light passing through them and have opposite characteristics.


What shape is a convex hexagon?

A convex hexagon is a simple polygon whose interior is a convex set. It is a six-sided polygon, and it has no angles pointing inwards, meaning that no internal angles can be more than 180 degrees.


Find the number of sides of a regular convex polygon whose angle is 40degrees?

140


The rotunda is the focal point of whose design for the University of Virginia?

Thomas Jefferson


Formula for finding no of sides of a convex polygon whose no of sides is 44?

The number of diagnol formed by a convex polygon having N sides is {N*(N-1)/2} - N .


What is a closed plane figure having three convex sides?

A triangle whose sides are curved outwards.


When does a concave lens act as convex lens?

A convex lens acts as concave lens when it is kept in a medium whose optical density is higher than the lens itself. And the vice-verse is also true .i.e, a concave lens can act as convex lens too .