Datasheet

CHAPTER 1 : BEFORE YOU SHOOT ■

Figure 1.3: The same focal length will produce different fields of view depending on the size

of the sensor/film.

Different digital cameras use different size sensors, so focal-length equivalents

will vary. For example, 30mm is considered a normal focal length for the Nikon D200

while 12mm is considered normal for the Sony F828. For now, most camera manufac-

turers provide 35mm focal-length equivalents when necessary, either on the lens hous-

ing or in the manual. If you can’t find the 35mm focal-length equivalent for your

particular camera, you can refer to the owner’s manual or to the manufacturer’s web-

site. With some digital camera specifications you will see a number referred to as a

35mm “multiplier factor.” Multiply this number by the focal length of your lens to get

the 35mm camera equivalent for your digital camera. For example, if the multiplier is

1.5 and you are using a 100mm focal length, 1.5

× 100mm = 150mm, which is the

35mm equivalent for your digital camera.

35mm film frame (36mm

24mm)

Nikon D200 frame (23.67

15.6mm)

Sony DSC F828 frame (8.8mm

6.64mm)

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