Science Investigatory Project Essay
Science Investigatory Project
Dissatisfaction and discouragement are not caused by the absence of vision. Many things from afar are cannot be seen by the naked eye. Unlike cameras, eyes don’t have the capacity to magnify or zoom. In today’s generation, many people call for the use of binoculars but not everyone can afford. Due to this problem, the researchers decided to conduct this study “Improvised Binoculars out of worn-out gadgets.” To seek an alternative and affordable binoculars. Binoculars are a pair of identical or mirror-symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes when viewing distant objects.
Most are sized to be held using both hands, although sizes may vary from opera glasses to large pedestal mounted military model unlike a telescope, binoculars give users a 3 dimensional image: for nearer objects the two views, presented to each of the viewer’s eyes from slightly different viewpoints, produce a merged view with an impression of depth. Modern binoculars consist of two barrel chambers with an objective lens, eyepiece and a prism inside. The prisms reflect and lengthen the light while the objective lenses enhance and magnify images due to stereoscopic vision. As telescopes were improved, binoculars evolved. Binoculars consist of an objective lens and eyepiece with two facing, right angle prisms arranged to invert and correct two facing, right angle prisms arranged to invert and correct the orientation of the image. The applications of binoculars are vast, ranging from being used in military operations to leisure activities. A must for bird-watchers and hunters, binoculars are even used at sporting events by spectators who may be seated far from the action, thus using binoculars to get clearer and closer views of the action. Many tourist destinations around the world also have swivel-mounted binoculars to allow tourists to get better views of distant objects. In professional situations, militaries use binoculars for day-to-day operations. Binoculars are essential for them as with the binoculars, the military personnel would be able to spot enemies at a distant and take the necessary action. Not only that, they can also safeguard their territory and prevent and intruders from coming in. Their use, together with sophisticated 21st century technology makes the military much more efficient than it previously was.
Statement of the Problem
The main purpose of the study is top produce a simple improvised binocular. The researchers aim to answer the following questions: a. What are the methods to be used in constructing simple prism binoculars? b. Are binoculars a good magnifier?
c. Compare the improvised prism binocular with commercial binoculars. Hypotheses
* Null Hypotheses (Ho)
There is no significant difference between the images magnified on the improvised prism binoculars and that on the commercial binoculars. * Alternative Hypotheses (Ha)
There is a significant difference between the images magnified on the improvised prism binoculars and that on the commercial binoculars. Significance of the Study
Binoculars are a handheld optical instrument composed of two telescopes and a focusing device, and usually having a prism to increase magnifying ability. Binoculars are used to view distant objects using both eyes. The applications of binoculars are vast, ranging from being used in military operations to leisure activities. A must for bird-watchers and hunters, binoculars are even used at sporting events by spectators who may be seated far from the action, thus using binoculars to get clearer and closer views of the action. Many tourist destinations around the world also have swivel-mounted binoculars to allow tourists to get better views of distant objects. An example can be the Grand Canyon, where tourists would not be able to see far away objects, thus these binoculars have been installed for the convenience of the tourists. In professional situations, militaries use binoculars for day-to-day operations. Binoculars are essential for them as with the binoculars, the military personnel would be able to spot enemies at a distant and take the necessary action. Not only that, they can also safeguard their territory and prevent and intruders from coming in. This will give the researchers an idea of making improvised prism binoculars. Some consider cans, lenses from worn-out gadgets and caps of plastic bottles as waste and there is nothing to do with them. But these materials can be a
good raw material that has the potential in making improvised binoculars, which will help to see distant objects, instead of buying those expensive binoculars. This is the reason why the researchers will make an improvised prism binocular. Scope and Delimitation
This study will only focus on making improvised prism binoculars from gadgets that are no longer in use or worn out. This study will show the steps and the procedures to make simple prism binoculars and show the comparison between the said binoculars and the commercial ones. II.
A. Review of Related Literature
History of binoculars
Almost from the invention of the telescope in 17th century the advantages of mounting two of them side by side for binocular vision seems to have been explored. Most early binoculars used Galilean optics; that is, they used a convex objective and a concave eyepiece lens. The Galilean design has the advantage of presenting an erect image but has a narrow field of view and is not capable of very high magnification. This type of construction is still used in very cheap models in and in opera glasses or theater glasses. The Galilean design is also used in low magnification binocular surgical and jewelers loupes because they can be very short and produce an upright image without extra or unordinary erecting optics, reducing expense and overall weight. They also have large exit pupils making centering less critical and the narrow field of view works well in those applications these are typically mounted on an eye-to-eye glass frame or custom-fit onto eye glasses. An improved image and higher magnification can be achieved in binoculars employing keplerian optics, where the image formed by the objective lens is viewed through a positive eyepiece lens (ocular). This configuration has the disadvantage that the image is inverted. Porro prism binoculars are named after Italian optician Ignazio Porro who patented this image erecting system in 1854 and later refined by makers like the Carl Zeiss Company in the 1890’s.
Binoculars of this type use a porro prism in a double prism Z-shaped configuration to erect the image. This feature results in binoculars that are wide, with objective lenses that are well separated but offset from the eyepieces. Porro prism designs have the added benefit of folding the optical path so that the physical length of the binoculars is less than the focal length of the objective and wider spacing of the objectives give a better sensation of depth. Thus, the size of the binoculars is reduced. Binoculars using roof prisms may have appeared as early as the 1870’s in a design by Achille Victor Emile daubresse. Most roof prism binoculars use either the Abbe-Koenig prism (named after Ernst Karl Abbe and Albert Koenig and patented by Carl Zeiss in 1905) or Schmidt-Pechan prism (invented in 1899) designs to erect the image and fold the optical path. They have objective lenses that are approximately in line with the eyepieces. Binoculars tend to come in two main styles, the Roof Prism and the Porro Prism design, both have their unique advantages and disadvantages over each other and so often it will be down to your specific needs and preferences as to which you should choose. Roof Prism Binoculars one of the two main styles of binoculars is the Roof Prism (the other being Porro Prism), this refers to the type of prism used in their construction. In this design the prism’s are aligned with each other in a straight line, and thus they tend to be sleeker and more compact binoculars than the Porro prism design. You can easily identify a roof prism binocular as the eyepieces and the large objective lenses line up with each other. Roof Prism Binoculars
* Compact Design
* Less internal parts than porro prism design, so less to go wrong and easier to make dust and waterproof. Disadvantages:
* The image quality of roof-prism binoculars can suffer slightly because of the aligned prisms, although the top models of the roof-prism and porro-prism binoculars are now generally considered to have equal optical quality. To be really good, roof prism binoculars have to be in the high price range. Do not attempt to economize on roof prism binoculars. * Good for Ideal general use binoculars that can be used for bird-watching, wildlife viewing and at sporting events. Porro Prism Binoculars
It is easy to identify a Porro Prism binocular because the eyepieces and the objective lenses are offset from each other (objective lens is not in line with the ocular lens), this is because of the design of the prism (porro)
used in its construction. Advantages:
• Porro prisms have objective lenses spaced wider than roof prisms, and so can produce a slightly better stereoscopic image than the roof prism design. • Cheaper to make quality porro prisms than roof prisms so they tend to be cheaper to buy. Disadvantages:
• Less compact design than roof prism binoculars
• More moving parts, more to go wrong and harder to make fully water and dust proof. Good For Like the roof prisms, porro prism binoculars make perfect general use optics ideal for things like bird-watching, wildlife viewing and at sporting events.
Review of Related Studies
The prismatic telescope is an astronomical telescope plus a pair of prisms for erecting the image. The most common example of this type of construction is the binocular instrument. One half of a binocular is a monocular. Some telescopes are used for a specific purpose and are named accordingly. A typical example is a spotting scope, which is used to view the target in rifle shooting. Prisms: Prisms are polished, angular pieces of glass, the kind commonly used in telescopes being 45-45-90-deg. prisms. The long side is the face, while the two short sides are the reflecting surfaces. The size of the prism is the width of the face Made specifically for telescopes, the prisms are grooved across the face in order to make a definite dividing line and avoid ghost images which would be caused by overlapping rays at this point. The ends are usually rounded to conserve space. The prime advantage of the prism erecting system is compactness. It adds somewhat to the bulk of the instrument but shortens the length considerably. The prism glass has an elusive quality of brilliance but actually the light loss through the two prisms is somewhat greater than through the two erecting lenses of a lens erecting system. The 23X prismatic spotting scope
This design calls for a 20-in. focal length objective, which, with a 22-mm. focal length eyepiece (from Army 6X), gives 23-diameter magnification.
Prisms are 1-in. face. The scope body is of wood construction in simple box form. The first prism, the one the light strikes first, is located in an upright position at the back of the box; the second prism is mounted flat on the box bottom. Plywood spacers hold the prisms in place and also provide for the passage of the cone of light admitted by the objective. The eyepiece is fitted in a threaded mount. This type of focusing is satisfactory at set distances but is much too slow for general use. If you want this scope for general observation, it should be fitted with spiral focusing like the 10X monocular to be described later. It would also be practical to focus with a simple draw tube system. The principal point of the construction is to get the various holes lined up square. Use prism center lines as a guide and locate all holes from one master pattern drawn on cardboard Base on which the floor flange is mounted pivots on a carriage bolt and is tilted by means of a tilting screw. Designing- prismatic telescopes
Designing your own prismatic telescopes follows much the same procedure as used for astronomical and terrestrials. Primary consideration should be given the objective and eyepiece. The prisms contribute nothing to “the magnification; therefore, the power you want must be obtained entirely by the ratio of FO to FE. Prisms should be of such a size or so located as to receive the full cone of light from the objective, although it is practical to sacrifice extreme edge rays. The layout (at top of drawing) is what you make to determine the size and location of prisms and also the general overall dimensions. In this example, the objective has a 52-mm. diameter by 193-mm. focal length (from Navy 7X binocular) and the prisms are 1-in. face (from Navy 7X). As used by the Navy, this glass has a 27-mm. eyepiece, which gives a magnification of 7 diameters. If you want higher magnification, you have to use a shorter focus eyepiece. The Army 6X binocular eyepiece, 22 mm, could be used and would give you 9X. The eyepiece shown uses an Army binocular eye lens, but a shorter focus field lens, the combination giving 20-mm. focus, hence, about 10X magnification. The preliminary calculation should determine the exit pupil and luminosity. This glass has excellent illumination at 92 percent. However, Don’t get the idea that the 13 percent rating of the 23X spotting scope is hopeless—13 percent is a good value for anything over 20X magnification. It is worth mentioning here that prism
instruments are often rated for illumination on the basis of the exit pupil squared. Thus, if the scope has a 5-mm. exit pupil, it would be rated 25. Using this calculation, the 100 percent standard would be the normal size of the eye pupil, squared: 25 for daylight and 49 for night. Bench setup
Set up the objective and focus on well-lighted copy or a bare light bulb, not less than 20 ft. from lens. Use tracing or waxed paper as a ground glass to pick up the image as in Fig. 49. Measure the distance from the rear side of the objective to the image plane. Start your layout and transfer this dimension to the layout. Next, put the two prisms face to face and move the assembly back and forth until you pick up a sharp image of the copy or light bulb. Measure the distance to the face of the first prism and set off this distance on your layout, now you will note that the distance the light travels through a 1-in. prism is 2 in., a total oX 4 in. for both prisms. Set off this distance, C, on your layout to establish the back image plane. Determine the image size. In this instance, the multiplying factor is .070, and this figure multiplied by the focal length of the lens (7% in.) gives .53 in. for the image size.
Call this Ha in. for an even figure and mark the image size at the normal image plane and again at the back image plane, as indicated by L. Draw lines K and M representing the marginal rays and the full cone of light. Your prisms must catch the marginal rays K and also as much of the weaker edge rays as possible. The best way to determine prism-placement is to make -two 1 by 2-in. oblongs of cardboard or celluloid. Manipulate these over your layout. The forward edge of the first oblong represents the face of the first prism. You can tell at a glance how far forward you can push it and still pick up the marginal rays. The distance between the two oblongs is the spacing between the prisms. The distance between the back edge of the second oblong and the back image plane must be sufficient to permit focusing. What you finally arrive at in this case is D, %<s-in. allowance for the distance the image plane will set inside the eyepiece tube; E, % in. for focusing travel; F, %-in. prism spacing; G, 2 in.’, the distance through the second prism; H, %-in. prism spacing again, coming back; I, 2 in. for the first prism, arriving at J,-the face of the first prism. This may sound complicated, but it is really very simple if you are actually on the job. If desired, you can now draw an outline of the prisms. This shows both prisms flat; the same way you test them in the bench setup. At this point J, it will be noted that the face of the prism catches all of the marginal rays and about halfway out to the lines representing the full cone of light. As mentioned before, it is practical to sacrifice some or all of the weak edge rays, so that this placement of the first prism face is quite satisfactory. What next? Well, you know that the maximum cone of light you can catch on the first prism is 1 in. in diameter at J, so lines drawn from here to image size at the back image plane will establish guide lines for hole diameters needed to pass this same cone of light back to the image plane. These lines are marked N in the drawing, and O, for example, shows the diameter of the hole at the back face of the second prism. If you want to use one or more glare stops ahead of the prisms, the hole diameters are determined in the same way, as at P. Monocular construction
You will need two wood blocks exactly 1 in. thick to house the prisms. The Vs-ia spacing between prisms is taken up by a spacer of %-in. plywood, and similar plywood pieces are used at the back and front of the housing. The whole thing is glued up like a triple Decker sandwich, the prisms being held securely in the cutouts and between the various layers. Work carefully to prism center lines. Be sure that prisms are exactly at right angles since any rotation here will rotate your image twice as much. Prisms must be spotlessly clean and polished. The eyepiece tube is 1 in. in diameter, this size permitting it to work alongside No. 1 prism; Focusing is by means of a spiral groove cut half way across the eyepiece. Shows the monocular partly assembled and also shows how the turning which joins the main tube to the prism housing is cut away to fit over the second prism covered with a gray pebble-grain oilcloth. General notes
Cut the main tube long when making any prism telescope. Check the final position of the objective by actually using the instrument; run the eyepiece in as far as it will go and then place the objective so that distant objects are in focus. Then the full focusing range is available e for picking up nearer objects. The 23X spotting scope£ will focus down to about 40 ft.; the 10X monocular to about 30 ft. or even 20 if you want to make it that way. If
you use spiral focusing, it is necessary to know in advance how much you will need for focusing. This travel will be very short with a short focus lens, but much longer with a long focus objective. Allow % in. for lenses less than 10-in. focus; % in., up to 14-in. focus; 1% in. at 18 and 1% in. at 20. These allowances will let you focus down to 30 or 40 ft. in all cases, -possibly closer. When you make a bench setup at close range , remember that this represents the maximum extension of your telescope. If you make a bench setup by focusing on a distant object (this is advisable if you are using an objective of over 20-in. focal length) the setup will represent the telescope at its shortest draw. The Kellne r type of eyepiece gives best results with all prismatic instruments. The objective should always be a cemented achromat. If the lens is not cemented l^^^^^^^ M when you get it, you can dummy test it by cementing with glycerin. Final cementing should be done with Canadian balsam; in a pinch you can use a good grade of water white (clear) lacquer. The diameter of the objective controls the luminosity of the telescope. The diameter of the objective does not control the field of view; except in the Galilean instrument, you can see just as much through, a small objective as a large one.