why we use to understand brightness and image

only for study

1. NAME: HUSNA HUSNAIN
ROLL NO: 2021-131
SUBJECT: TECHNICAL
WRITING AND
PRESENTATION SKILL

2. TOPIC:
BRIGTHNESS &
AFTERIMAGE

3. Introduction

Definition: Brightness refers to the intensity of light
After Image: a visual illusion where an image remains after the
original has disappeared


Importance: Understanding brightness and after image is crucial
for display technology and visual design

Objective: To explore the concepts of brightness and after
image

4. Brightness
Measure of the amount of light emitted or reflected by an
object

Unit: Candelas per square meter (cd/m²)

Types: Luminance, IL luminance, and Radiance Effects:
Affects visibility, readability, and visual comfort

Range: 0 (black) to 100 (white

5. Have you ever noticed that when you are looking at something
and lights are suddenly out you will continue to see the
previous image for short while or after you looked at an object
for a long time you will see some sort of spots for a few
seconds. These are called Afterimages. An afterimage is an
image that continues to appear in one's vision after the
exposure to the original image has ceased.

6. TYPES OF AFTERIMAGE

1.POSITIVE AFTERIMAGE

2. NEGATIVE AFTERIMAGE

7. Positive Afterimage: when light enters our eyes the
photoreceptor HT cells in the retina send chemical
and electrical signals to our brains to provide vision

when the light is turned off the photoreceptor cells
will continue to send signals for less than half a
second in which we can still see the original image,
this is a positive afterimage

8. NEGATIVE

AFTER IMAGE : It's caused by the desensitization of
the photoreceptor cells and you will see the
complementary color of the original image

9. Human eyes have three types of color receptors in retina.
red, green and blue detectors, when the retina is exposed to
light they will detect the wavelength and generate signals to
our brains so we can see colors. however these receptors will
lose sensitivity gradually

10. Conclusion:
Brightness and after image are critical aspects
of visual perception
Understanding their effects is essential for
display technology and visual design