Questions

1.  Describe the difference between Flash Guide Number and Flash Guide Aperture.

A flashes power is determined by its guide number, with low guide numbers indicating a weak or less powerful flash than one with a high guide number.
Flash guide aperture is the aperture used with the distance and power setting of the flash (guide number).

• Ambient exposure is controlled by shutter speed
• Flash exposure is controlled by aperture

2.  What is the colour temperature (CT) of an electronic flash discharge

5,500 - 6,000K

3.   In the given situation below there is a subject that is lit by a light source from the left side and a reflector on the right side. A light meter can be used to determine the level of illumination on each side of the subject. That being the case if the meter indicated f8 on the lit side and f5.6 on the shaded side the lighting ratio would be;

2:1

4.   If the readings were f8 and f1.4 respectively what would the new lighting ratio be?

4:1