Distances from the source of the lens 0.08 from the screen to the lens 0.016 calculate the main focal length of the lens?

Let’s start with a short entry given:

f = 0.08;

d = 0.016.

To find:

F -? (main focal length of the lens).

To solve the problem, we apply the thin lens formula:

1 / d + 1 / f = 1 / F;

where d is the distance from the object to the lens;

f is the distance from the lens to the image;

F is the focal length of the lens.

Let us express from the formula F:

1 / F = (f + d) / f * d;

F = (f * d) / (f + d).

So, we substitute the values into the resulting formula to calculate the focal length and make the calculations:

F = (0.08 * 0.016) / (0.08 + 0.016) = 0.00128 / 0.096 = 0.01 (3).