Optical Instruments

Optical Instruments

An optical instrument either processes light waves to enhance an image for viewing, or analyzes light waves (or photons) to determine one of a number of characteristic properties.

The examples of optical instruments are:

• Eye
• Camera
• Lup
• Microscope
• Telescope
• Projector

Eyes

Eyes are organs that detect light. Different kinds of light-sensitive organs are found in a variety of animals. The simplest "eyes", in even unicellular organisms, do nothing but detect whether the surroundings are light or dark, which is sufficient for the entrainment of circadian rhythms and may allow the organism to seek out or avoid light, but hardly can be called vision.

Part of Eye

The part of eye are :
-Retina
-Cornea
-Iris
-Lens
-Pupil
-Eye nerve

• Retina: retina has function to arrest shadow which mouldable by eye lens
• Cornea: cornea has function to receive light and continue light and protect eye lens from feather.
• Iris: the iris has function to give color to eye.
• Eye Lens: eye lens has function to make thing shadow.
• Pupil: pupil has function to organize light intensity.
• Eye Nerve: eye nerve has function to continue signal from retina to brain.

Eye Accommodations

The purpose of the optics of the mammalian eye is to bring a clear image of the visual world onto the retina. Because of limited depth of field of the mammalian eye, an object at one distance from the eye might project a clear image, while an object either closer to or further from the eye will not. To make images clear for objects at different distances from the eye, its optical power needs to be changed. This is accomplished mainly by changing the curvature of the lens. For distant objects, the lens needs to be made flatter, for near objects the lens needs to be made thicker and more rounded.

Eye Diseases

There are 3 kind of eye diseases:

-Near sighted (Miopi)
-Long sighted (Hipermetropi)
-Old eye (Presbiopi)

• Miopi: can not see object with far distance in clearly.
• Hipermetropi: can not see object with near distance in clearly.
• Presbiopi: can not see object with far and near distance in clearly. Presbiobi usually occurs in elderly! 

Camera

A camera is a device used to capture images, either as still photographs or as sequences of moving images. If there is iris in eye, in camera there is diaphragm.
Camera consist of convex lens which can arranged for focus real shadow in order to fall to film.
Characteristic of shadow in film is obvious, capsize and smaller.

Lup

Lup is lens which use to see small thing become bigger and clear.

Microscope

A microscope is an instrument for viewing objects that are too small to be seen by the naked eyes. 

Projector

Projector is optical instrument that has function to projecting picture to screen until the shadow of the thing appear bigger and more clear. Projector is divided by 2, there are episcop and diascop. Episcop is projector that has function to projected untranslucent object.
Diascop is projector that has function to projected translucent object.

Examples of diascop:
-Slide Projector
-Film Projector
-Overhead Projector

Photo Sources:

Ma own collection

Best Regards,

Sherly Ok ^^ 

How to change our blogs templates!!! :D

Blog Tempah jeidtingIf ya already had blog in blogspot, wordpress or in blogdetik, ya can make up your blog with many choices of templates. But, I use blogspot to make ma own blog. These are the ways to change your blog template in blogspot:

1. In easy way, ya can open www.google.com and search 'bout blogspot templates!
2. Then, there're many websites that contains many different templates to download.
3. Click one of them and ya can choose your favorite template according to types of templates like blue, pink, stretch, nature, seashore, etc! 
4. Choose one your favorite template fer make up your blog! :D
5. After that, ya may download your choosen template or open it!
6. Ya find that template HTML and copy it!
7. Ya may sign in your email and your password in www.blogspot.com to go to your blog dashboard!
8. Click layout!
9. After the layout open, ya can choose edit HTML!
10. Erase your old template HTML, ya can click Ctrl + A and then backspace in your keyboard to get eaisier in erase it!
11. Paste your choosen template HTML in there! 
12. If ya want to preview before apply that template, ya can click preview.
13. After all, ya can can save your choosen template by click save template!
14. View your blog and that's your blog with your choosen template! 
15. Enjoy it!! :D

Oh yeah, ya can make your own templates and your own HTML fer your template!

The ways to change your old template become your own template:

1. Ya may sign in your email and your password in www.blogspot.com to go to your blog dashboard!
2. Click layout!
3. After the layout open, ya can choose edit HTML!
4. Erase your old template HTML, ya can click Ctrl + A and then backspace in your keyboard to get eaisier in erase it!
5. Paste your own template HTML in there! 
6. If ya want to preview your blog before apply that template, ya can click preview.
7. After all, ya can can save your own template by click save template!
8. View your blog and that's your blog with your own template! 
9. Enjoy it!! :D

Ya can change your blog template again if ya getting bored with your old template! ^^

I think it's same to change the template in www.blogdetik.com and www.wordpress.com!

Photo Sources: 

www.wishix.com

veerendher.wordpress.com

www.geckoandfly.com

Best Regards, 

Sherly Ok ^^

Physic Experiment!!

Refraction

Refraction is the change direction of light or light turning.
Example of refraction in our daily life are:
-When we drop a pipe to glass that content water, we see the pipe like broken.
-When we catch a fish in aquarium, the fish position is not at the position we see.

Picture: The pipe had a refraction in the water
It seems like broken

Medium Refraction Index

Medium Refraction Index is equivalent of light speed in empty gas space with light speed in a medium. The formula is

  n = c/cn

Willebrod Snell (1581 – 1626), a mathematic scientist, through many experiment he did found relation between coming light and refracted light that known by the law of Snellius, that is:

Coming light, normal line, and refracted light located in 1 flat area
The projection equivalent of coming light projection and refracted light at border area between 2 medium is permanent numeral. The permanent numeral definite to refraction index.

Base by the law of Snellius, medium refraction index can found by the projection equivalent of coming light and light refraction light projection at 2 medium border area.

The formula is:
  n = D’o/B’o

Details:

The cut point of coming light and refraction light at medium border area become the middle point of circle (o). When cut point coming light circle side (D) and refracted light (B) Projected into border area, so D’o is the projection of coming light (Do) and B’o is projection of refracted light (Bo). With this, the medium refraction index formed like in slide before.

Characteristic of Light Refraction

To understand the refraction of light direction while through border area between 2 medium, so we use the characteristic of refracted light that is:

1. Coming light from close less into more close medium will refracted nearly normal line. With this, refraction angle (r) will more small than coming angle (i). 

2. The light come perpendicular border area so not have direction changes (not refracted but just directed).

3. Coming light from more close medium to close less medium will refracted more far from normal line. With this, the refracted angle (r) will be bigger than coming angle (i).

Light Refraction through Lens

Lens is a trasparent thing that are limited using two bending surface, or one bended and one isn’t. There are two type of lens, convex and concave.

Convex Lens

Convex Lens is a lens that the center of the lens is thinner than its side. Convex lens consist of three kinds of shapes : Biconvex lens, Planconvex lens, and Concave Convex lens. Convex lens is the same as positive lens. Convex lens can gather lights (convergent).

Like a mirror, lens has three special light, too. Those are:
-Incoming light parallel with the main fuse are refracted through the focus point.
-Incoming light through focus point are refracted parallel the main fuse.
-Incoming light through the main point of the lens are going without refraction.

Refraction in Convex lens:

Concave lens

Concave lens is a lens that its center are thicker than its side. Concave lens consist of three kind, Biconcave, Planconcave, and Convex Concave. Concave lens is the same as negative lens. Concave lens can spread lights (divergent).

Like a convex lens, concave lens is also has three special light:
-Incoming light parallel with main fuse are refracted like its coming from the focus point.
-Incoming light to the focus point are refracted parallel with the main fuse.

-Incoming light from the center lens’ point are going without refraction.

 The refraction that made from concave lens are always Invisible, not reversed, and smaller.

Kinds of onvex and concave lenses: 

Photo Sources:

Ma own photos, some made by myself. ^^

Best Regards,

 

Sherly Ok ^^