Digital camera

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Quick Questions

Shade in the A or B circle for each question.

1. What does the lens of a digital camera do?

A It focuses light onto the image sensor

B It stores the photo as a file

2. What is the image sensor made of?

A One large microphone

B Many light-sensitive cells

3. What does each light-sensitive cell on the image sensor become in the final picture?

A One pixel

B One whole image file

4. What does a cell on the image sensor record?

A The brightness and colour of the light that hits it

B The sound waves that hit it

5. Which picture has more detail?

A An image made of fewer pixels

B An image made of more pixels

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1lens		AMore pixels, not fewer, give a more detailed picture, because each pixel records a smaller part of the scene.
2image sensor		BThe part of a digital camera that focuses light onto the image sensor
3Each light-sensitive cell on the image sensor becomes one pixel of the final image		C12 megapixels > 2 megapixels
4More pixels give more detail, but the image file needs more storage space		D1 cell = 1 pixel
5The lens turns light into digital data.		EIt is the image sensor that turns light into digital data. The lens only focuses the light onto the sensor.
6Fewer pixels give a more detailed picture.		FA chip made of many light-sensitive cells that record brightness and colour and turn light into digital data

Definitions

digital camera

Fill in the Blanks

Complete each line of code by filling in the missing parts.

light ← ____.FOCUS(scene)

data ← ____________.CAPTURE(light)

FOR EACH ____ IN sensor pixel ← cell.READ() NEXT cell

____(image, "photo.jpg")

IF pixels _ 1000000 THEN detail ← "high" ENDIF

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A light ← scene.reflect()

B sensor.focus(light, lens)

C data ← sensor.convert(light)

Question 2

A FOR EACH cell IN lens

B pixel ← cell.read()

C image.add(pixel)

D NEXT cell

Question 3

A camA ← 12000000

B camB ← 2000000

C IF camA < camB THEN

D OUTPUT "camA more detail"

Question 4

A cell ← sensor.cell(1)

B pixel ← cell.read()

C image.add(lens)

Question 5

A photo ← camera.capture()

B photo.name ← "IMG_001.jpg"

C memoryCard.delete(photo)

Answer Key

Digital camera

Section A: Quick Questions

A — It focuses light onto the image sensor

B — Many light-sensitive cells

A — One pixel

A — The brightness and colour of the light that hits it

B — An image made of more pixels

Section B: Match the Pairs

lens → The part of a digital camera that focuses light onto the image sensor

image sensor → A chip made of many light-sensitive cells that record brightness and colour and turn light into digital data

Each light-sensitive cell on the image sensor becomes one pixel of the final image → 1 cell = 1 pixel

More pixels give more detail, but the image file needs more storage space → 12 megapixels > 2 megapixels

The lens turns light into digital data. → It is the image sensor that turns light into digital data. The lens only focuses the light onto the sensor.

Fewer pixels give a more detailed picture. → More pixels, not fewer, give a more detailed picture, because each pixel records a smaller part of the scene.

Section C: Definitions

digital camera — Input device: a lens focuses light onto an image sensor of light-sensitive cells; each cell becomes a pixel of digital data, stored as an image file. More pixels give more detail.

Section D: Fill in the Blanks

light ← lens.FOCUS(scene)

data ← image_sensor.CAPTURE(light)

FOR EACH cell IN sensor
    pixel ← cell.READ()
NEXT cell

SAVE(image, "photo.jpg")

IF pixels > 1000000 THEN
    detail ← "high"
ENDIF

Section E: Spot the Error

B — The lens focuses the light onto the image sensor. The sensor does not focus light. The line should be lens.focus(light, sensor).

A — The light-sensitive cells are in the image sensor, not in the lens. The loop should be FOR EACH cell IN sensor.

C — camA has more pixels than camB, so it gives more detail. The condition must be camA > camB, otherwise the output message is wrong.

C — Each sensor cell becomes a pixel, and the pixels make up the image. A lens is not a pixel, so the line should be image.add(pixel).

C — The image is stored as a file on the memory card. It must be saved, not deleted. The line should be memoryCard.save(photo).