Accurately Predicting the Focal Length For Four Lens Systems

Abstract: We tried to accurately predict the focal length of the four lens systems, 100 mm lens, 200 mm lens, compound lens system, unknown lens. This is done by measuring the position of the all focus image after using the optical track with the attached light, the display image and the white display panel placed behind the lens system. The optimal value of f100 is determined from the unweighted calculation using the value of f100 = (0.096 ± 0.0004) m, the percentage error of 6%, the fractional error of 0.4%, and the difference of 1σ.

The microscope was originally developed with only two lenses, the objective lens and the eyepiece. The objective lens is basically a magnifying glass, the design focal length is very small, and the eyepiece usually has a long focal length. This has the effect of generating enlarged images of nearby objects. Typically, additional illumination sources are used as the magnified image becomes dark due to energy preservation and diffusion of light over a larger surface area. Modern microscopes, called compound microscopes, have many lenses (usually four) to optimize functions and enhance image stability. Compare the microscope with a slightly different microscope, display side by side side-by-side images, and create a stereoscopic binocular view to be displayed in three dimensions when used by humans

Devices that focus or diverge light by refraction are called lenses. Lenses are characterized by their focal length: the condenser lens has a positive focal length and the diverging lens has a negative focal length. The smaller the focal length, the stronger the convergence or divergence of the lens. The focal length of a simple lens in the air is given by the formula of the lens manufacturer. The incident collimated beam is focused by the convergent lens onto the focal point on the lens distal of the lens. This is called the back focus of the lens. Light from a finite distance object is far from the focal length, not the focal length, the closer the object is to the lens, the more distant the image is from the lens

The double lens system consists of a converging lens followed by a diverging lens, each lens having a focal length of 15 cm. This system is used to form an image of short nails located 1.5 cm tall, upright, 25 cm from the first lens. The two lenses are separated by a distance of 60 cm. Please see the attached pictures. (Refer to Figure 3-26 for the ray tracing diagram of this problem.) 1 Isosceles prism (25 mm face, 25 mm length, 25 mm mm) 2 45 ° - 45 ° - 90 ° prism (25 mm ) Leg, 35 mm hypotenuse, 25 mm thick) 2 diode laser pointers (5 mW or less) 1 spherical instrument 1 lenticular lens (diameter 75 mm, focal length 150 mm) One biconcave lens (75 mm) Diameter 150 mm focal length) Protractor 1 white cardboard screen Screen index card, white paper, (81/2 "x 11" and 11 "x 17"), masking tape and ruler