The camera as an art tool
A camera records light through a lens. Photographers can choose framing, timing and focus. Photography added a way to record appearances and influenced how some painters worked.
What a learner can do afterwards
- Say what the lens does and what the sensor or film does
- Name three choices a photographer makes: what is in frame, when to press, what is sharp
- Identify a photographic reference as a tool for planning a painting
- Discuss whether a photograph's main aim is recording information, persuading viewers or arranging visual elements, with a reason and awareness that these aims can overlap
1 · Read
Light from the scene enters the lens. The lens bends light to form an image on the sensor or film, which records it. Different scene points form different image points. The whole scene does not focus to one point.
You have examined pictured space. Framing chooses what is included; timing chooses the moment; focus selects the subject to make sharp. Automatic modes can help. Check that autofocus selected your intended subject.
Aperture is the lens opening. Depth of field is the range of distances that looks acceptably sharp. With the lens, focus distance and framing unchanged, a wider aperture usually reduces that range. Background blur also depends on the lens and distances; it is not guaranteed.
Painting, drawing and other methods recorded appearances before photography. Artists already made expressive and imagined scenes. Some painters used photographs as references or explored new treatments of light, movement and viewpoints. Photography influenced artists in different ways; painting continued.
A photograph can record information, persuade viewers and arrange visual elements. These aims overlap. Compare stated aims: readable prices stress information; cropped colour patterns stress arrangement. A dry riverbed photo paired with a water-saving message can support persuasion.
The lens forms an image; the sensor or film records it. Choose or check frame, moment and focus. Photographic aims can overlap.
Lesson, questions, image-recording diagrams and learning cards written for this dataset.
Four readings and learning cards written for this dataset.
More to read
Settings and the recorded light
Aperture describes the lens opening. Exposure time describes how long light is recorded. With other conditions fixed, a wider opening or longer exposure lets more light reach the sensor. A shorter exposure can reduce blur caused by movement. Digital ISO affects the brightness response to recorded light; changing it does not let more light through the lens. Higher ISO can make noise more visible. Automatic modes can choose settings, so compare the result with the photograph you intended.
Keep the parts of an image separate
Think of a sign with two letters. In a sharp camera image, light from each part of each letter reaches a corresponding part of the image. All that light must not collapse into a single spot. The lens changes the light's direction to form the image. Focusing places the image of the selected subject at the recording surface. The sensor or film receives the pattern and records it. Forming the image and recording it are different jobs.
A sign seen in a mirror
You can photograph a sign seen in a plane mirror. Light from the sign reflects from the mirror into the camera. The sign appears behind the mirror, where the reflected rays seem to come from. This apparent image is called virtual. The light does not actually travel from behind the mirror. The camera lens uses the reflected light to form a real image, where rays meet on the sensor or film. The virtual mirror image and the recorded camera image are different images.
Collecting sky light
An optical telescope uses a lens or mirror to collect light and form an image. For photography, a detector records that image. For direct viewing, a telescope can instead be used with an eyepiece. Not every telescope observation is a photograph. Under comparable conditions, a larger collecting area gathers more light from a faint source. Clear detail also depends on the instrument and observing conditions. Collecting more light does not by itself guarantee a clear picture.
2 · Watch
En anglaisTake it off screen
Where it sits
Learn first
Optional connections
This opens up
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.