DB-PZ-03 · The Camera's Eye (BG: Окото на камерата)
track
PZ · The Guardians (safety systems for children) · lesson 3 of 8
level
Explorer (use · recognise · explain in words) · two levels: ages 7–10 (grades 1–4) and an extra task for ages 11–13 (grades 5–7)
duration
10–15 min on screen + 10–15 min without a screen (with other children or an adult)
school link
supports Human and Nature / Technology and Entrepreneurship as a cross-curricular topic; practises the idea of an angle and reading a plan (the ages 11–13 task measures an angle with a protractor)
publisher
East Accelerator Foundation (Фондация „Източен Акселератор“) · host: kagami.bg
access
free · no account · no data collected · works offline
Explain that a camera sees only inside its field of view — a slice like a piece of pizza — and that a place it does not see is a blind spot
Turn and widen a camera's view in a game and find a direction where it sees both the door and the window
Explain in simple words: a wider view sees more but each thing is smaller; a narrower view sees less but far things look larger and clearer
(ages 11–13) Place a second camera so that the two cameras cover each other's blind spots
KEY CONCEPTS
field of view: the part of the room a camera can see; everything outside it is not seen
blind spot: a place no camera sees; in the game, the area right under the high corner camera is also not seen because the camera looks forward and down
wider angle → more of the room, things smaller; narrower angle → less of the room, far things larger (Wikipedia, Angle of view); in the game this is simplified as a longer “clear reach” for a narrower view (game numbers)
two cameras in opposite corners can see each other's blind spots
privacy (where cameras may and may not look) is only mentioned and is the topic of lesson 6
STRUCTURE
goal → 1 Remember (3 warm-up questions: how far you see without turning your head, the building's eye, hide and seek) → 2 Story (invented: two children build a cardboard model of their classroom with a camera, 60–90 s) → 3 Worked example (table: field of view, blind spot, lens; wide vs narrow) → 4 Try it (Predict: does a camera see everything in a room? → Run: top-view SVG room with a corner camera, sliders for direction and width, objects light up inside the view → Change: missions “see the door and the window” and “hide Bobby in a blind spot” by tapping the plan or preset buttons) + extra box for ages 11–13 (second camera in the opposite corner) → 5 Unplugged (cardboard tube camera, torch beam on the floor, find the blind spot, draw the view on paper) → 6 Make your own (draw your room from above with a camera and its view; ages 11–13: two cameras, no blind spot at the door, measure the angle) → 7 What I learned (3-question check + skill badge, no points) → 8 I have a question (form: the child writes ≤280 chars, the parent enters an e-mail and consents; double opt-in; plus "Was it useful?" / "We did the lesson" buttons — aggregate counts only)
ANSWERS
predict: b — no, a camera sees only its slice of the room
mission 1: e.g. direction about 25–30° and width about 40–60° (game) — door and window both light up; a very wide view does not reach the far door in the game
mission 2: e.g. right under the camera, the corner by the plant, or any point outside the slice
ages 11–13: a second camera in the opposite corner, turned towards the first, sees the place under the first camera
check: q1 a (a place the camera does not see) · q2 c (sees more, but everything is smaller) · q3 b (shine at the wall and the floor, never into eyes)
SAFETY
torch: never shine it into anyone's eyes; keep a small light on in the room; move slowly; an adult nearby
no talk of burglars or thieves; positive frame: the child is a detective who checks what a camera sees
privacy only mentioned in one sentence (lesson 6); nothing to buy; no personal data entered or stored; the page works offline
NEXT
DB-PZ-04 · Smoke and Heat · back: DB-PZ-02 · I Sense, I Think, I Signal
SOURCES · LICENCE
link only, facts retold in our own words: Wikipedia, Angle of view (photography) (en.wikipedia.org/wiki/Angle_of_view_(photography)) — shorter focal length gives a wider angle of view; for a given camera–subject distance, longer lenses magnify the subject more; checked 2026-11-01
licence: CC BY-SA 4.0 · https://creativecommons.org/licenses/by-sa/4.0/
METADATA
path
6 · social impact
determinant
physical environment
sdg_target
4.7
who_criterion
accessibility
impact_type
prevention · education
DIGCOMP 3.0
framework
DigComp 3.0 (JRC144121, doi:10.2760/0001149)
primary
none (technology-understanding lesson: how safety systems work; no primary DigComp 3.0 competence)
secondary
1.3 Managing information (reading a plan and a field of view)
mapping
proposed 2026-11-01 by the lesson goal · confidence: medium · not a measured outcome
VERIFIED · 01.11.2026AI help: yesreviewer: awaiting teacher and psychologist
The Camera's Eye
In lesson 1 you found out that the camera is the building's eye. But does it see everything? Today you are a detective: you will find out what a camera sees and where its blind spot is.
⏱ 10–15 minExplorerThe Guardians · 3grades 1–7 · two levels
You will be able to explain what a field of view and a blind spot are, and find the blind spot in a room.
For the parent: a one-page guide — questions for dinner and a game with a cardboard tube and a torch.
progress0%
01Remember
Think about each question, then open the answer.
Look straight ahead without turning your head. What do you see?
You see ahead and a little to the sides. You do not see what is behind you. Your eyes have a limit.
What is the building's eye?
The camera. You remember it from lesson 1 — it sees a picture in front of it.
Where do you hide in hide and seek?
Where the seeker is not looking — around a corner, behind a door. Today we will look for places like that for a camera.
02Story
This story is made up.
Nia and Bobby are making a cardboard model of their classroom. They stick a little camera in the top corner.
“Now the camera sees everything!” says Bobby.
Nia puts a torch where the camera is and switches it on. A bright patch appears on the floor, like a slice of pizza.
“Look,” she says. “The bright part is what the camera sees. And the teacher's desk is in the dark.”
“And it's dark right under the camera too!” Bobby says, surprised. “It looks forward, not under itself.”
The teacher leans over the model. “You have found a blind spot. How can you fix it?”
Bobby smiles. “We'll turn the camera. Or we'll put another one in the other corner!”
03Worked example
A camera does not see the whole room. It sees only one slice — like a slice of pizza that starts at the camera.
The word
What it means
📐 Field of view
how wide the camera sees — how big the slice is
🙈 Blind spot
a place the camera does not see
🔍 Lens
the camera's glass eye; it decides how wide the camera sees
↔️ Wide
Sees more of the room. But each thing in the picture is smaller.
➡️ Narrow
Sees less of the room. But things far away are larger and clearer.
A camera is usually high on the wall and looks forward and down. Think: does it see right under itself? Check in the game.
Where cameras may look and where they may not — we will talk about that in lesson 6.
04Try it now
1 · Predict
A camera in the corner of a room. Does it see the whole room? Choose before you check.
2 · Run: turn the camera
This is a room seen from above. The camera is in the top left corner. The coloured slice is what it sees. The things the camera sees light up in green.
3 · Change: two missions for the detective
Hide Bobby: tap a place on the plan or choose a button.
For older children · ages 11–13
Add a second camera in the bottom right corner. Set the two cameras so that each one sees the other's blind spot — and the place under the first camera. Can Bobby still hide anywhere?
05No screen: a cardboard camera
You need: an empty cardboard tube (from kitchen roll), a torch, paper, a pencil, a ruler and an adult with you. You can be the camera or the detective — or just watch the first round.
The camera. One child sits in the corner of the room. They look only through the tube, with one eye. The tube does not move.
The detectives. The others move slowly around the room. The camera says “I see you” or “I don't see you”. Where is the blind spot? Put a slip of paper on the floor there.
Under the camera. Stand right next to the camera child. Does the tube see you? Does it see the camera child's own feet?
The torch. In a half-dark room, put the torch on the table and point it at the floor. The bright patch shows what the camera “sees”. Put some toys down — which ones are in the light? Put the tube in front of the torch. What changed?
The drawing. Draw the room from above. Put a dot for the camera and draw two lines with the ruler — this is the slice it sees. Colour in the blind spot.
For older children · ages 11–13Measure the angle of the slice on the drawing with a protractor. Put a second child with a tube in the opposite corner. Is there still a blind spot? Draw both slices in different colours.
✋
The torch — only at the wall and the floor
Never shine it into eyes — not someone else's and not your own. Leave a little light on in the room and move slowly.
06Make your own
Make a plan of your room from above. Where would you put a camera so that it sees the door?
Draw the room, the door and the window.
Put the camera in one corner and draw its slice with a ruler.
Colour the blind spot in another colour.
Show the plan to someone at home and explain what the camera sees and what it does not.
For older children · ages 11–13Draw a plan with two cameras so that there is no blind spot in front of the door. Write down the angle of each camera in degrees. What do you gain and what do you lose if you make one camera wider?
07What I learned
A camera sees only its own slice — its field of view.
A place the camera does not see is a blind spot. It can also be right under the camera.
Wide — you see more, but everything is smaller. Narrow — you see less, but far things are larger and clearer.
Look straight ahead without moving: how far to the sides do your eyes reach?
Check yourself
1. What is a blind spot?
2. The camera looks wider. What happens?
3. How do you play with the torch?
📷
Skill badge: “I find the blind spot” It is yours when you can show someone what a camera sees and where its blind spot is. No points and no ranking — only a skill.
08I have a question
Do you still have a question? Write it here. It goes to your parent, not to strangers. Your parent confirms their e-mail first.
The form is loading… If it does not appear, write your question on paper and show it to a parent or teacher.
·Sources
Title: The Camera's Eye (DB-PZ-03) · Author: Children's Library, East Accelerator Foundation · Source: original content and original game code, 2026 · Rights: CC BY-SA 4.0.
Wikipedia — “Angle of view (photography)”: a lens with a shorter focal length sees a wider angle; a longer lens sees a narrower angle but shows things at the same distance larger. Checked 01.11.2026.
Licence:CC BY-SA 4.0 · Children's Library, East Accelerator Foundation, 2026. You may share and adapt this lesson if you credit the author and keep the same licence. Learning is free forever.
