Exposure

The important components of any camera are: Box (light-tight) Hole or Lens (to let light in) Shutter (to open and close to let light in at the right time) Film / light sensitive electronic chip Box (light-tight)

= Total amount of light which hits the film Exposure = Total amount of light which hits the film Film and electronic chips require the right amount of light to produce a ‘correct’ exposure. Modern cameras often have a built-in light-meter to measure how bright the light is, so that the photographer can get a ‘correct’ exposure.

‘Correct’ exposure Too much or too little light?

Controlling the Exposure There are two main ways that we can control the exposure (how much light hits the film):

Controlling the Exposure 1. Shutter ‘speed’ Changes how long the camera lets light hit the film A whole number of seconds … 1 second … 2 seconds … 3seconds Or a fraction of a second ½ second … ¼ second …. 1/8 …. 1/15 etc

Work out the missing shutter speeds in this list: Shutter speeds are usually given as a fraction of a second and each shutter speed on a camera is normally about twice as big, or half as big as the next shutter speed. Work out the missing shutter speeds in this list: ½ ¼ ___ 1/15 1/30 ___ 1/125 ___ ___ 1/8 1/60 1/250 1/500

Controlling the Exposure 2. Aperture (hole) Do big holes (apertures) let in more or less light ? More light

Aperture (hole) F22 f16 f11 f8 f5.6 f4 f2.8 What do you notice about the f number as the hole (aperture) gets bigger? Each aperture is twice as big (or half as big) as the aperture next to it.

Aperture (hole) F22 f16 f11 f8 f5.6 f4 f2.8 Each aperture is twice as big (or half the size) as the aperture next to it. QUESTION: an f8 aperture lets in twice as much light as f___ and half as much light as f ___ 11 5.6

F22 f16 f11 f8 f5.6 f4 f2.8 Shutter Speeds ½ ¼ 1/8 1/15 1/30 1/60 1/125 Aperture and shutter are both used simultaneously to control the exposure

F22 f16 f11 f8 f5.6 f4 f2.8 Shutter Speeds ½ ¼ 1/8 1/15 1/30 1/60 1/125 If we double the size of hole but also halve the shutter speed, what happens to the amount of light hitting the film (i.e. the exposure) ? It stays the same

Assignment Complete the worksheet - Exposure – Aperture & Shutter speed Keep this sheet in the back of your sketchbook to refer to.

Produce a page in your sketchbook on Exposure. Prep Work Produce a page in your sketchbook on Exposure. It should include a shoot that experiments with exposure. Note down shutter speeds and apertures (remember to focus on landscape photography) Add an explanation of aperture and shutter speed, diagrams explaining these and how they are controlled and the effect they have.