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