1) Take the lens and a piece of white paper out in direct sunlight.Rachelrific said:experimentally finding the focal length of small biconvex lens
Would this work with a far away light source indoors, like a bright lamp across the room? There's a liquid component to my lens and I don't want it to freeze outside.Tom.G said:1) Take the lens and a piece of white paper out in direct sunlight.
2) Focus the Sun on the paper by varying the lens-to-paper distance.
3) When in focus, the distance from the lens to the paper is the focal length.
Should be around -3 diopters. I made them out of acrylic (CNC'ed then heavily polished).Bandit127 said:Well done fabricating your lens - that is no mean feat. (I do this for a living - contact lenses are concave/convex lenses about 14 mm in diameter).
What radius did you intend to make back and front? And what is it made of, glass or acrylic/perspex?
Yeah, that should work. You can calculate the error introduced by the finite distance to the light source to see if it's acceptable to you.Rachelrific said:Would this work with a far away light source indoors, like a bright lamp across the room? There's a liquid component to my lens and I don't want it to freeze outside.
If you are working in dioptres then your friendly optician/optometrist will be have exactly the right instrument to measure the power of your lens. They will also be able to assess the quality of the focus.Rachelrific said:Should be around -3 diopters. I made them out of acrylic (CNC'ed then heavily polished).
The focal length of a lens is an important parameter that determines its ability to focus light. Therefore, experimentally finding the focal length of a small biconvex lens helps in understanding its optical properties and performance.
The materials needed for this experiment include a small biconvex lens, a light source (such as a laser or light bulb), a screen or white paper, a ruler, and a clamp or stand to hold the lens and screen in place.
The procedure involves setting up the materials and equipment in a dark room, placing the lens between the light source and screen, adjusting the distance between the lens and screen until a sharp image is formed, and measuring the distance between the lens and screen. This distance represents the focal length of the lens.
It is recommended to conduct at least three trials and take the average of the results for more accurate measurements. This will also help in identifying any inconsistencies in the measurements and improving the overall accuracy of the results.
Some potential sources of error in this experiment include human error in measuring distances and aligning the lens and screen, variations in the light source and intensity, and imperfections in the lens itself. It is important to minimize these errors by carefully following the procedure and conducting multiple trials.