BY : SARIYATI,S.T

OPTICAL INSTRUMENT

EYES

Cornea : the outer transparent thin membrane , to protect the eyes and refracting the light

Iris : the coloured part of eyes to regulate the light intensity pass through the eyes

Pupil : an opening where light pass through the eyes

Lens : to refract the lightRetina : inner surface of

eye the rods and cones cells

EYES

THE POWER OF ACCOMODATION : the ability of crystalline lens to adjust its shape to focus the image on the retina

PP = Punctum Proximum

PR= Punctum Remotum

VISION DEFECTS MYOPIA

(NEARSIGHTED) HYPEROPIA

(FARSIGHTED) ASTIGMATISM PRESBIOP

EMETROPY/NORMAL EYES

PP = 25 cm or 30 cmPR = ∞

Normal eyes produces image that is real, inverted, smaller

VISION DEFECTS

MYOPIA/NEARSIGHTED

PP < 25 cmPR <∞To get clear image of

distance object, a nearsighted person must use concave lens

di = -PR (cm)

P = 100/f = 100/-PR

HYPEROPIA/FARSIGHTED

PP > 25 cmPR =∞To get clear image of

distance object, a nearsighted person must use convex lens

di = -PP

1/-PP + 1/do = 1/f

P = 4-(100/PP)

ASTIGMATISM

Cause by the unsphereness of the cornea

Corrected by using cylindrical lens

PRESBIOPI

Caused by the reducing of the accomodation power because of aging

Corrected by using double lens/bifocal lens (convex and concave lens)

CAMERA

No

Eyes Camera

1

2

3

4

Produces image that is real, inverted, smallerFocusing he image by accomodation powerEyes part to control light intensity :Iris

Eyes part where image is constructed :Retina

Produces image that is real, inverted, smallerFocusing the image by adjusting the lens positionCamera part to control light intensity : DiaphragmaCamera part where image is constructed :Negative film

HAND LENS

Contains of one convex lensProduce image that is virtual, upright,

bigger

HAND LENS

Tanpa lup

fDengan lup

mata akomodasi maksimum

f

Dengan lup

mata tanpa akomodasi

Angular Magnification (max. accomodation) :PP

Ma f 1PP

Maf

Angular Magnification )without accomodation) :

PP=Sn = Punctum Proximum=titik dekat mata

MICROSCOPE

Has two convex lenses : eyepiece lens and objective lens

Objective lens produces image : real, inverted, bigger (object is placed between Fobj and 2Fobj )

Eyepiece lens produces image : virtual, upright, bigger

M obj = =

Mtot = Mob x Meye

MICROSCOPE

Length of the microscope : the distance between the eyepiece and the objective lens

Microscope

Microscope

fok

fokfobBenda

Bayangan

Obyektif Okuler

M total = Mob x Mok

Mob = S’ob

SobMok =

Sn

fok

Tanpa akomodasi

SnMok = fok

+ 1

Akomodasi maksimum

TELESCOPE

Astronomical Telescope/Teropong Bintang

Contains : 2 pcs convex lens (objective lens and ocular lens/eyepiece)

Produces image hat is virtual, inverted, bigger

The length of the telescope = d= fob+fok

Angular Magnification= Ma = fob/fok

Galilean/Opera Telescope=Teropong Panggung

Contains : 2 pcs lens (objective lens=convex, and ocular lens/eyepiece=concave)

Produces image hat is virtual, upright, biggerThe length of the telescope = d= fob+(-fok)

Angular Magnification= Ma = fob/fok

Binoculars

Contains 2 pcs convex lenses , and 2 pcs of triangular prisms

Terestrial Telescope/Teropong Bumi

Contains : 3 pcs convex lens (objective lens, inversion lens, and ocular lens/eyepiece)

Produces image hat is virtual, upright, biggerThe length of the telescope = d= fob+4fp+fok

Angular Magnification= Ma = fob/fok