Using your camera on manual settings. • Exposure • Shutter speed • Aperture • Light meters • Film speed / ISO
Exposure • Correct exposure – records all tones as they were in the original subject. • Overexposure – all tones are lighter than in the original subject, highlights look bleached out and lack detail • Underexposure – all tones are darker than in the original, shadows lack subtle detail.
Over exposed
Correctly exposed
Under exposed
Underexposed photograph, not enough light let into the camera, all tones darker than original, shadow areas lack information and detail.
Overexposed photograph, too much light has been let into the camera, all tones are lighter than original subject, highlights are ‘blown’ and lack information and detail.
Correct exposure, tones look similar to how they appeared at the original scene, there is still subtle detail in the shadows and highlights even in this case where there is extreme contrast between the lightest and darkest areas.
Three things control exposure
•Shutter speed. •Aperture. •ISO
Shutter speed • The shutter is a blind inside the camera that opens and closes when the shutter release button is pressed. • The amount of time this shutter is opened can be changed to control the amount of time light enters the camera. • Common shutter speeds in DSLR cameras range from 1/4000 second to 30 whole seconds and ‘BULB’ setting enables the shutter to be open as long as the shutter release button is pressed down. • The shorter the time (e.g. 1/4000) the less light is let in. • The longer the time (e.g. ½) the more light is let in.
Shutter inside the back of SLR film camera. Similarly positioned inside the DSLR camera.
Aperture • The aperture is an adjustable hole inside the lens. • The hole (aperture) can be made bigger to allow more light to enter the camera. • Or it can be made smaller to let less light to enter the camera. • The aperture is expressed as an f. number or f. stop. • Common f numbers are: • F1.4 f2 f2.8 f4 f5.6 f8 f11 f16 f22 • There are also thirds of stops between each whole f stop.
A range of apertures from large to small. Large aperture lets in more light. Small apertures let in less light.
The ISO set here is 6400, the highest available on most DSLR cameras. This means the sensor is very sensitive to light and can produce an image without very much light. It is therefore ideal for shooting in poor lighting conditions (low / available light).
Getting the right exposure • Automatic modes – photographer does not control exposure, the camera does it for them. • Manual mode – photographer must set the shutter speed, aperture and ISO to correctly expose the photograph.
Screen showing Manual settings on DSLR Number on top left – Shutter speed Number on top right – Aperture (f.stop) Exposure meter scale below.
What do I set everything on?
ISO • ISO – Go as low as you can. • Why? • A low ISO (100) will give a noise free image.
Shutter speed and aperture • In usual circumstances, avoid a shutter speed slower than 1/60 second otherwise you may get camera shake. • Adjust the APERTURE and / or SHUTTER SPEED until the light meter reading is on the zero setting, not + and not – • + means there is too much light so reduce aperture size or increase the shutter speed. • - means there is not enough light so increase the aperture size or slow down the shutter speed.
How to achieve correct exposure using M (Manual mode). • Set the Mode dial to ‘M’ so you have full control over exposure settings. • Look at the scale below the shutter speed and aperture settings: • Press the shutter release button lightly and the light meter will display how much light you have entering the camera. • It will show if you have the right amount of light, too much light or too little light.
Light meters • Digital SLRs have TTL (through the lens)light meters built into the camera.