Lesson 2: The Camera Obscura

What part is the lens? In a basic pinhole camera obscura, the "lens" is simply the tiny hole (the pinhole) that lets light in. In more advanced cameras, a curved piece of glass (a convex lens) sits in that hole to bend the light and make the image sharper.

Is the image upside down or right side up? The image projected inside a camera obscura is always upside down and flipped backwards left-to-right.

Why is the image this way? Light always travels in straight lines. Because the pinhole is so tiny, light reflecting from the top of an object outside travels down at an angle through the hole and hits the bottom of the screen inside. At the same time, light from the bottom of the object travels up through the hole and hits the top of the screen. When these straight lines cross path at the pinhole, the image flips.

Camera Obscura: A dark box or room with a tiny hole that projects an upside-down picture of the outside world onto a screen inside.

Single-Lens Reflex (SLR): A camera that uses a mirror inside to bounce the upside-down image right-side up so you can see it correctly through the viewfinder.

Twin-Lens Reflex (TLR): A camera with two lenses—one for your eyes to focus the image, and one to capture it.

Convex Lens: A lens that curves outward. It helps bend light rays together so a camera obscura image looks much brighter and sharper than a simple pinhole can manage.

Concave Lens: A lens that curves inward to spread light rays apart.

Photograms: Pictures made without a camera by placing items right on light-sensitive paper and exposing them to light.

Creating: Conceiving and developing new artistic ideas and work.
Anchor Standard #1. Generate and conceptualize artistic ideas and work.
Anchor Standard #2. Organize and develop artistic ideas and work.

Historical content and recall and applied to the application of creation.

DDOK Level 2 (Classify, Compare & Distinguish): Students will identify the basic parts of their handmade camera and compare its function directly to a modern camera.

DOK Level 4 (Analyze & Progress): Students will analyze how light behaves inside their camera and explain how this simple box laid the groundwork for all modern photographic history.

Showing that a camera works the same today as years ago. The basic parts and function has not changed from when it was invented all the way up to the modern day camera.

Modern day cameras have no connection to the past. The old camera are useless and not important.

Students may be aide in the process of making the camera. For example someone may have to cut or tape for the student.

To check if the students mastered the concept, we will look at three questions:

Was the student able to successfully assemble the camera obscura?

Did the finished camera function properly (did it project a visible, upside-down image)?

Did the student understand how to use it, and could they explain why the image is inverted?

An example camera (a modern digital or analog camera to show the class).

Build Materials for each student/pair: Construction paper, aluminum foil, scissors, tape, tracing paper (to act as the viewing screen), and a tack or pin to poke the pinhole.