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A very simple method to calculate the focal length of a lense is to focus it front of the sun and find out a sharp, small point at ground and you have to calculate the distance between that point and lense.... However this gives you approximate result not very accurate resut... For accurate result you have to go in to physics lab and work with optical bench... Thanks
Wiki User
∙ 12y ago
Wiki User
∙ 14y agoBasically, the focal length is the distance from the center of the lens to the focal point or the principal foci.
The calculations will depend on the curvature of the lens, the lens thickness, and the refractive index of the material that the lens was made out of. Wikipedia has a great description of lens focal length, see the link to this article in the related link section below.
Wiki User
∙ 16y agofocal length is measured in mm
Wiki User
∙ 16y agoIt should be written on the lens in 'mm'
Wiki User
∙ 13y agoApply this ,1/f = 1/v + 1/u
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How do you calculate magnification?
Divide the focal length of the objective lens by the focal length of the eyepiece.
Whats the focal length of a lens?
The focal length of a lens is the distance from the principal foci to the center of the lens.
Explain how the focal length changes as a convex lens becomes flatter?
The focal length of a lens is the distance from the center of the lens to the point at which it focuses light rays. The bigger the focal length, the more powerful the lens. ChaCha!
How to calculate x of a lens knowing only the focal length which is the distance from the lens to the image of sun formed by it correct me if I'm wrong?
1/(focal length) = 1/(distance of object) + 1/(distance of image) is the formula for calculating x of a lens knowing only the focal length which is the distance from the lens to the image of sun formed by it.
Length of a lens is the distance from the center of the lens to its principal focus?
It is called the focal length. It is equal to 1/2 times r, and is positive on concave mirrors and negative on convex mirrors.
Does the focal lens length have three classifications?
yes, focal lens length has three classifications
What is defined as the distance between a lens and its focal point?
focal length of the lens
What is the focal length of the convex lens?
The distance from the centre of the lens to the focal point.
What will happen to the focal length of a lens if it is cut into half vertically?
When the lens is cut vertically then the focal length of the lens will increase.the focal length will become approx double.
If a telescope has an objective lens of 3 inches what is the focal length?
The size (diameter) of a lens does not determine its focal length. The amount of curvature of the lens does. Citing a diameter for a lens doesn't help us find the focal length. Lenses are ground to specifications that allow short or long focal length. The more curved the lens, the shorter the focal length. You can see this if we specify a given curvature and then start to "flatten" the lens. The focal length will get longer and longer as the lens is flattened. When the lens is flat (has to curvature) the lense has an infinite focal length, just like a piece of flat glass.
Which lens in a refracting telescope has a shorter focal length?
The eyepiece will have a shorter focal length than the objective lens has.
How does change in the thickness of lens change the focal length of lens?
Not at all. The focal length is determined by the curvature of the surfaces.
