Presentation is loading. Please wait.

Presentation is loading. Please wait.

Resolution. Resolution: Refers to the sharpness and clarity of an image. The term is most often used to describe monitors, printers, and bit- mapped graphic.

Similar presentations


Presentation on theme: "Resolution. Resolution: Refers to the sharpness and clarity of an image. The term is most often used to describe monitors, printers, and bit- mapped graphic."— Presentation transcript:

1 Resolution

2 Resolution: Refers to the sharpness and clarity of an image. The term is most often used to describe monitors, printers, and bit- mapped graphic images. In the case of dot-matrix and laser printers, the resolution indicates the number of dots per inch.

3 The display resolution of a digital television or computer display typically refers to the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by all different factors in cathode ray tube (CRT) and flat panel or projection displays using fixed picture-element (pixel) arrays.

4 Just resolved Not resolved Two red stars

5 The Rayleigh criterion is the generally accepted criterion for the minimum resolvable detail - the imaging process is said to be diffraction-limited when the first diffraction minimum of the image of one source point coincides with the maximum of another. The Rayleigh Criterion

6 Sine of the angular separation of two sources Wavelength of the wave, Width of the gap,b OR Sine b A simple practical test is called Rayleigh’s criterion

7 A car’s headlights are 1.5m apart, and give out light of average wavelength 500 nm. You are 5.0 km away and the diameter of the pupil of your eye is 3.0 mm. would you see two separate headlights or just a patch of light? This small angle approximation: sin = = 1.5 = 1.5 = 0.00030 Radians 5.0 5000 Also, = 500 = 500x10^-9 = 0.00017 b 3.0 3.0x10^-3

8 two source interference Two sources a distance d apart are sending out identical waves in phase. We observe an interference pattern with lines of constructive interference at particular angles and lines of destructive interference at other angles.

9 young's equation : In 1801, this experiment was performed for the first time by Thomas Young. Young expanded the mathematical model presented above by relating the wavelength of light to observable and measurable distances. Today, an experimental setup similar to that of Thomas Young's is commonly used in a Physics classroom to repeat the experiment and to measure the wavelength of light. In the experiment as it is commonly performed today, light from a laser beam is passed through two narrowly-spaced slits in a slide or sheet of paper. The light diffracts through the slits and interfere in the space beyond the slits. Thus, the slits serve as the two sources. The interference pattern is then projected onto a screen, paper or a whiteboard located several meters away. The spatial separation of nodes and antinodes on the screen is clearly seen. above

10 Here is a Java applet which can be used as an aid to understanding the patterns which are produced when two circular periodic waves interfere. This is often termed a two source interference pattern. Basic operation: The 'Small', 'Medium', and 'Large' radio buttons control the size of the waves.

11 young's equation

12 Diffraction grating In optics, a diffraction grating is an optical component with a regular pattern, which splits (diffracts) light into several beams travelling in different directions. The directions of these beams depend on the spacing of the grating and the wavelength of the light so that the grating acts as a dispersive element. Because of this, gratings are commonly used in monochromators and spectrometers.opticsdiffracts dispersivemonochromatorsspectrometers

13 Diffraction grating http://www.youtube.com/watch?v=gxgfthefKbg

14 Hessa Abdullah Ghayda Al-khater 11A Al-wakra independent secondary School for Girls


Download ppt "Resolution. Resolution: Refers to the sharpness and clarity of an image. The term is most often used to describe monitors, printers, and bit- mapped graphic."

Similar presentations


Ads by Google