Finding lens spacing and magnification in a fresnel projector design

[sharp81]

hi,
i am in need of help pretty quickly here.i will have to design a projector design using a fresnel lens and the projection lens.i need to find and derive the equations for the lenses and calculate the distances between the lenses and the lens and the screen.
this is what i require to have :
d1 - distance from the light source to the fresnel lens
d2 - distance between the fresnel and the projection lens
d3 - distance between the projection lens and the screen
f1,f2 - focal lengths of the fresnel lens
f3,f4 - focal lengths of the projection lens
In my case i know the values of the focal lengths and the distance between the light source and the fresnel lens ie d1 which will be equal to f1.I am not sure if the fresnel lens can have the second focal length

i will have to find d2 and d3. also i need to find the net magnification factor for the light source which will be my object.
any help will be greatly appreciated.
harish

 

[azntoon]

The equations for the lenses are typically derived from the thin lens equations and the magnification equations. The thin lens equation is given by 1/f = 1/d1 + 1/d2, and the magnification equation is given by M = -d2/d1. You can use these equations to determine the distance between the lenses (d2) and the distance between the lens and the screen (d3). To determine the net magnification factor, you will need to multiply the magnification of both lenses together (M1*M2). The net magnification factor will then be the product of the two magnifications. For example, if f1 = 10 cm, f2 = 5 cm, f3 = 20 cm, and f4 = 10 cm, then d1 = 10 cm, d2 = 20 cm, and d3 = 30 cm. The magnification of the fresnel lens will be -2, and the magnification of the projection lens will be -1. The net magnification factor will then be -2*-1 = 2. I hope this helps!

 

[R0man]

Hello Harish,

To calculate D2, D3, and net magnification for a projector using a fresnel lens and projection lens, you can use the following equations:

D2 = (f1 * d1) / (f1 + f2) where f1 is the focal length of the fresnel lens and d1 is the distance from the light source to the fresnel lens.

D3 = (f3 * d2) / (f3 + f4) where f3 is the focal length of the projection lens and d2 is the distance between the fresnel lens and the projection lens, which we calculated in the previous equation.

To find the net magnification, you can use the formula:

M = (d3 / d1) * (f1 / f3) where d3 is the distance between the projection lens and the screen, and f1 and f3 are the focal lengths of the fresnel and projection lens respectively.

I hope this helps with your projector design. Good luck!