The Human Eye and the Camera SONNY P. DE LEON Master Teacher I

Components of the lesson Parts and function of the Human Eye vital in seeing objects Parts and function of the Camera in forming images

Seatwork No.2 The Human Eye and the Camera 1. What are the parts of the eye vital in seeing objects? 2. Describe the mechanism of how the human eyes see an object. 3. How will you describe the image formed in the eye? 4. What is accommodation? 5.Identify the parts of the camera responsible in the production of image? 6. Explain how the image is formed in the camera. 7. Describe the image formed in the camera? 8. Draw the ray diagram for the image formation in the eye and the camera.

9. What are similarities of the parts of the camera and human eye? 10. What are the specific differences bet. camera and eye?

Do you see a similarity between a camera and the human eye? Eye vs. Camera

ANATOMY OF HUMAN EYE

Image Formation in the Eye Image formed is real, inverted and diminished.

The eye uses a convex lens system to form a small upside down image of anything in front of it. The iris controls the amount of light going into the eye. If you walk into a dark room, the hole in the middle of the iris (the pupil) grows larger. T he cornea and the watery liquid behind it do most of the focusing of the rays. The lens itself makes small focusing adjustments. It doesn’t move backwards or forwards like the lens in a camera or projector. Instead it becomes thinner or fatter.

The retina is the ‘screen’ which detects the image. It contains millions of tiny cells which are sensitive to light. The cells send signals along the optic nerve to the brain. Your brain gives you an upright view of the world. But it isn’t always the same as the image in your eye. The eye uses a convex lens system to produce a real inverted image of an object in front of it. Light entering the eye passes first into the cornea. It is where where most refraction occurs. A resulting image is focused on the retina as an inverted image. The brain receives the message through the optic nerve and interprets the image as an upright object.

Clear images of near and far objects are not visible together. To view closer objects after viewing distant objects requires a change in the curvature of the lens of the eye. -For viewing distant objects the lens is thinner and is focal length is longer. - For closer objects the lens thickens in the middle and its principal focus is closer to the lens. ACCOMMODATION The ability of the eye to change its focal length.

1.2 Describe the mechanism of how the human eyes see an object. CORNEA AQUEOUS HUMOR PUPIL IRIS LENS RETINA BRAIN

The CAMERA

Image formation in the Camera The image formed is real, inverted, and reduced.

Lens - It draws the light into the camera and focuses it on the film plane. Aperture- opening in the camera through which light enters. Shutter - It open and closes to control the length of time light strikes the film. Shutter Release - The button that releases or "trips" the shutter mechanism. Iris diaphragm- It changes the size of the lens opening/ regulate the light that enters the camera Viewfinder - The "window" through which you look to frame your picture. Film – place behind the iris diaphragm where the image is formed.

Film Rewind Knob -This knob rewinds the film back into the film cassette. Camera Body - The casing of the camera which holds the encloses the camera pats. Flash Shoe - This is the point at which the flash or flash cube is mounted or attached. Self-Timer - This mechanism trips the shutter after a short delay - usually 7 to 10 seconds - allowing everyone to be in the photograph. Shutter Speed Control - This know controls the length of time the shutter remains open. B

RECALL!

The eye uses a convex lens system to form a small upside down image of anything in front of it. The iris controls the amount of light going into the eye. If you walk into a dark room, the hole in the middle of the iris (the pupil) grows larger. T he cornea and the watery liquid behind it do most of the focusing of the rays. The lens itself makes small focusing adjustments. It doesn’t move backwards or forwards like the lens in a camera or projector. Instead it becomes thinner or fatter What are the parts of the eye vital in seeing objects?

The retina is the ‘screen’ which detects the image. It contains millions of tiny cells which are sensitive to light. The cells send signals along the optic nerve to the brain. Your brain gives you an upright view of the world. But it isn’t always the same as the image in your eye.

1.3 How will you describe the image formed in the eye? It is always real, inverted, and magnification < 1.

1.3 Identify the parts of the camera responsible in the production of image? Lens - It draws the light into the camera and focuses it on the film plane. Aperture- opening in the camera through which light enters. Shutter - It open and closes to control the length of time light strikes the film. Iris diaphragm- It changes the size of the lens opening/ regulate the light that enters the camera Film – place behind the iris diaphragm where the image is formed.

1.4 Explain how the image is formed in the camera. APERTURE Iris diaphragm LENS FILM

Comparison Between the Eye and the Camera VS.

Eye vs. Camera

Similarities of the parts of the camera and human eye EyeCamera RetinaFilm Lens IrisIris diaphragm PupilAperture EyelidShutter B

Specific Differences bet. Camera and eye CameraEye LensRigidDeformable FocusingBy moving lens relative to film By changing shape ApertureControlled by diaphragmControlled by Iris ExposureControlled by shutterContinuous Light-sensitive SurfacePhotographic filmRetina

Ray Diagram of Camera and Eye CameraEye

Image formation in the Camera The image formed is real, inverted, and reduced.

Image Formation in the Eye

BACK..

Compound Microscope Use a lens combination to make small objects near the objective seem more visible. objective lens: real,inverted, and magnified eyepiece lens: virtual, erect and further magnified

Refracting Telescope Use a lens combination to make distant objects more visible

That’s All.. THANK YOU VERY MUCH!!