Contextualization

Theoretical Introduction

A camera obscura is one of the oldest and most fundamental experiments in Physics, directly linked to the discovery of optical principles. It is an opaque box with a small hole on one side, where the light from the object to be viewed enters and projects an inverted image on the opposite wall of the hole.

The concept of a camera obscura is essential for understanding geometric optics and image formation, the basis for the operation of photographic cameras and our eyes. When passing through the small hole, the light from each point of the object propagates in a straight line and spreads inside the chamber, forming an inverted image of the object on the opposite wall.

This projection occurs due to the principle of the rectilinear propagation of light. When the light rays pass through the hole and encounter a dark environment, they intersect and form an inverted image on the opposite wall. This image can be captured on photographic paper or perceived directly by the observer.

Contextualization of the Theme

The camera obscura has numerous practical applications in the modern world, especially in the field of photography and cinema. It is the basis of operation for photographic cameras, where the light that enters through the lens (the hole) is captured on a digital sensor or film, forming the image.

Furthermore, the camera obscura is also used in the field of astronomy, for the safe observation of solar eclipses, for example. Its principle is still applied in some medical equipment, such as tomographs.

Understanding its operation is the starting point for comprehending fundamental principles of physics and optics, as well as the functioning of many devices in our daily lives.

Practical Activity

Activity Title: Creation and Experimentation of a Camera Obscura

Project Objective

To understand the optical principles of image formation and their application in daily life. Develop technical and socio-emotional skills such as teamwork, time management, proactivity, communication, and problem-solving.

Project Description

Students, divided into groups of 3 to 5 people, will create a camera obscura using simple and accessible materials. The group will test their camera obscura, document the process and results, calculate the ideal size of the chamber and the distance from the camera to the object to obtain a sharp image, and then write a detailed report.

This project should last approximately 12 hours per participant, and students will be responsible for managing their time and coordination within the group.

Required Materials

• A large cardboard box (can be a shoebox)
• Aluminum foil
• Adhesive tape
• Needle
• Scissors
• Tracing paper or white paper sheet
• Pencils, pens, markers
• Ruler

Step by Step

1. Cut a small square on the side of the box, approximately 4 cm on each side.
2. Cover this small square with aluminum foil and secure it with adhesive tape.
3. Use the needle to pierce the aluminum foil, forming a small hole, being careful not to make the hole too large.
4. On the inside of the box opposite the hole, attach the tracing paper or white paper sheet with adhesive tape. This will be the screen where the image will form.
5. The camera obscura is ready for use!

Students should:

1. Perform tests with different distances between the camera obscura and the object to be focused, documenting all observations.
2. Calculate the ideal size of the chamber and the distance from the camera to the object to form a sharp image, considering the principles of geometric optics.
3. Write a report on the project, including: Introduction (contextualization of the theme, relevance, real-world application, and project objective); Development (theory, detailed activity, methodology used, results obtained, and discussion); Conclusion (summary of the main points, lessons learned, and conclusions about the project); Bibliography used.

Writing the Written Document

When writing the document, students should:

• Clearly and organizedly communicate the concepts addressed, the construction process, and the results of the camera obscura experiment.
• Correctly use physical and photographic terminologies.
• Describe the procedures performed accurately and in detail, including the challenges encountered and how they were resolved, highlighting the importance of collaborative work.
• Include graphs or tables to present the collected data, as well as photographs of the project at different stages.
• Conduct a critical analysis of the results, establishing connections with the theoretical principles studied and their conclusions.