Lens makers Equation Calculator, Formula, Calculation of Focal Length

Lens makers Calculator:


The human eye is a natural lens, There the muscles control the focal length (they can change the shape of the lens). However, some people have eyes whose lenses do not focus light properly.

So they have to use glasses – synthetic lenses. With the right arrangement of lenses, we can make microscopes that can magnify small objects and telescopes that can magnify distant objects. If you want to know the magnification of a simple lens, check out our thin lens calculator.

Another use of lenses is camera. Like the eye muscles, the lens system can adjust its focal length (with the camera as a slide lens) to focus the image on the camera film. Do you want to make lenses with the desired focal length? If so, don’t worry, you can use our tool Lens makers Equation Calculator,

Because it is very simple. Enter data like index of refraction, radius of curvature of media to get focal length. Read on to learn about lens makers formula, steps to calculate focal length using radius of curvature, focal length, radius of curvature, index of refraction etc.

Find lensmakers equation examples.

Lens maker’s Equation:

Lens maker’s equation is one divided by the focal length f(cm) in centimeter is equal to the refractive index of lens material and multiply the one divided by the the Radius of curvature of lens surface close to the light source R1(cm) in centimeter and divided one by the Radius of curvature of lens surface father from the light source R2(cm) in centimeter and addition the refractive index n-1 and  multiply the thickness of lens d and divided by the refractive index lens material n and multiply the Radius of curvature of lens surface close to the light source R1(cm) in centi meter and multiply the the Radius of curvature of lens surface father from the light source R2(cm) in centimeter.Hence the lensmakers equation can be written as

1/f(cm) =(n-1)(1/R1(cm) -1/R2(cm) +(n-1) *d /(n*R1(cm) *R2(cm))

Where f= is the focal length

N=is the refractive index of lens material

R1=is the Radius of curvature of lens surface close to the light source

R2=is the Radius of curvature of lens surface father from the light source

D=is the thickness of lens

Reducing the lensmakers formula further simply by assuming the lens to be very thin

D=0 we get the equation  as

1/f=(n-1)*(1/R1-1/R2)

Example:1

Calculate the focal length of the lens if the refractive index 2.5,Radius of curvature of surface  1 is 8cm,Radius of curvature of surface 2 is 16cm?

Answer:

Given that

Refractive index=2.5

Radius of curvature 1=8cm

Radius of curvature 2=16cm

We know the focal length of a thin lens is given by

1/f=(n-1)*(1/R1-1/R2)

1/f=(2.5-1)(1/8 -1/16)

F=11cm

Example:2

Calculate the focal length of the lens if the refractive index 4.5,Radius of curvature of surface  1 is 7cm,Radius of curvature of surface 2 is 9cm?

Answer:

Given that

Refractive index=4.5

Radius of curvature 1=7cm

Radius of curvature 2=9cm

We know the focal length of a thin lens is given by

1/f=(n-1)*(1/R1-1/R2)

1/f=(4.5-1)(1/7 -1/9)

F=9.0cm

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