Unit 57 – PhotographyLenses
Lenses of different focal lengths allow photographers to have more creative control
1. Standard lens2. Wide-angle
lens3. Telephoto lens4. Macro lens
Why do we usedifferent lenses?
On a 35mm camera the standard lens has a focal length of 50mm.
The standard lens produces image with a perspective close to the human eye.
On digital cameras the sensor is often smaller than the 35mm frame.
This means that the focal length of a lens is effectively 1.5x longer.
So a 50mm lens on a digital camera is effectively a 75mm lens.
A 35mm lens on a digital camera is effectively a 50mm lens.
Wide-angle lenses have:
1. A wider field of view – they show more2. A bigger depth of field for any given
aperture3. A greater sense of space – they extend
perspectiveWide-angle lenses are typically used for landscape and architectural photography and have a focal length less than 50mm
Telephoto lenses have:
1. A smaller field of view – they magnify the image
2. A small depth of field for any given aperture3. A smaller sense of space – they compress
perspectiveTelephoto lenses are typically used for wildlife and sports photography and have a focal length greater than 50mm
200mm telephoto lens
80mm telephoto lens
50mm standard lens
21mm wide-angle lens
Macro lenses have an ability to focus much closer to the subject than normal lenses.
Attachments such as extension tubes and bellows fit between the camera and lens and allow normal lenses to be used for close-up photography
Macro lenses come in a range of focal lengths but all have the ability to focus much closer than normal lenses
Filters can be used on lenses to enhance or change the image.
Neutral density filters act like sunglasses to cut down the amount of light reaching the film or sensor. They come in a range of strengths.
Yellow, orange and red filters can be used with black and white film to make blue skies appear darker
21mm
50mm
80mm
35mm 200mm
50mm
200mm
21mm
Wide-angle lens
Telephoto lens
Task for today:
In your groups each person must take a series of pictures that show the properties of:
• Wide-angle lenses• Standard lenses• Telephoto lenses