Aim: To examine characteristics of a converging lens and the images they create. Also to examine the focal length and how the focus point may be found and developing rules for locating an image via ray drawings and the intersection of rays. Chromatic aberration will also be explored and why it happens.
Theory: Both lenses and mirrors have a principle axis, yet a lens has two focal points as opposed to a mirror that has only one. When considering converging lenses, the primary focal point (PF) can be found on the opposite side of the lens in regards to the light. The secondary focal point (SF) being on the same side as the light source. Focus points on thin double convex lenses are located at either side of the lens, measured from the middle of the lens itself (see below). Chromatic aberration is a problem of converging lenses that will also be explored in this experiment. A description of each image produced will also be given (attitude, type, magnification and location).
Apparatus: The main tools (apparatus) used in the experiment consist of a ray box containing cards which allow one, two, three or four rays onto a sheet of paper at a time so that rays path from the box to the mirror will be able to be traced. Also two (2) different types of converging lenses, one being cylindrical while the other being spherical, the difference being that the spherical one is used for viewing, the cylindrical one for use with the ray box. These lenses are one of many different sorts of lenses in the "lens box". The use of a ruler would also be helpful so that accurate measurements may be taken.
Method:
1. A cylindrical lens was placed on paper and traced around, a principal axis was drawn making sure that it's at rights angles to the lens. The ray box was switched on (exposing only one ray) and lined up parallel to the principle axis, a mark where the ray leaves the box was made as well as where it hits the lens (on both sides) and where the ray bisects the principle axis. After this, the ray box was removed and using a ruler, rays were accurately drawn. The focus point (f) was measured to be of length 7.3cm (7.25).
2. The lens was replaced back on a sheet of paper with ray box emitting three rays, the middle ray lined up on the principle axis, marks were made where the ray's intersected at on the principle axis and this was measured to be the primary focus point.
.... 'It is a moment when the visible escapes from the timeless incorporeal order of the camera obscura and becomes lodged in another apparatus, within the unstable physiology and temporality of the human body'. Crary further demonstrates the shift in vision's location from camera to body by examining the way in which it was reproduced in various optical devices invented during this same period, specifically the stereoscope, the kaleidoscope, the phenakistiscope, and the diorama. His examination is based on a provocative premise: 'There is a tendency to conflate all optical devices in the nineteenth century as equally implicated in a vague collective drive to higher and higher standards of verisimilitude' (110). According to Crary, such an approach tends to neglect entirely how some of these devices were expressions of what he calls 'nonveridical' models of perception.
Human skin is a multi-layered structure. It is generally divided into two layers, the epidermis and the dermis. Below the dermis a subcutaneous fat layer is found. The epidermis can be further divided into several sub-layers. These are the stratum corneum, the stratum lucidum, the stratum granulosum, the stratum spinosum, and the stratum germinativum. The stratum germinativum is usually referred to as the basal layer.
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Thanks to his studies, especially after the translation of Kitâb al-Manâzir (The Book of Optics), many scholars and scientists were inspired. Later European scholars were able take what he had discovered and further our knowledge about cameras and optics in general. Alhazen’s creation of the pinhole camera is the reason why cameras and other important inventions were created, such as eye-glasses, magnifying glasses and telescopes were created, as scholars and scientists knew how images are reflected in our eyes. He especially influenced Isaac Ne...
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