Kodak DCS Pro SLR/n manual Focal length, Front-Curtain Sync, Guide number, Histogram, Manual flash

Focal length	The distance from the principal point to the focal point. In 35 mm-format
	cameras, lenses with a focal length of approximately 50 mm are called
	normal or standard lenses. Lenses with a focal length less than
	approximately 35 mm are called wide angle lenses, and lenses with a focal
	length more than approximately 85 mm are called telephoto lenses. Lenses
	that allow the user to continuously vary the focal length without changing
	focus are called zoom lenses.
Front-Curtain Sync	The flash fires an instant after the front curtain of a focal plane shutter has
	completed its travel across the film plane. The camera operates this way
	with the flash sync mode at Normal Sync. See also “Rear-Curtain Sync.”
Guide number	The guide number indicates the power of a flash in relation to ISO. Guide
	numbers, quoted in either meters or feet, are used to calculate the f/stop for
	correct exposure as follows:
	f/stop = guide number / flash-to-subject distance
	Using a selected aperture, calculate the required flash-to-subject distance
	with the formula:
	flash-to-subject distance = guide number / f-stop
	Use to determine the maximum flash-to-subject distance.
Histogram	The image histogram shows the range and distribution of tonal values for an
	image. The tick marks at the bottom of the histogram represent
	photographic stops relative to the factory-determined 18% gray level. The
	range of stops is from +3 to -7. The double bar tick mark indicates the
	exposure value associated with 18% gray. Tick marks to the right of the
	double mark indicate one-stop increments brighter than 18% gray, and tick
	marks to the left indicate one-stop increments darker than 18% gray.
ISO	ISO is the international standard for representing film sensitivity. The higher
	the number, the greater the sensitivity, and vice versa. For example, ISO 200
	is twice as sensitive as ISO 100, and half that of ISO 400. When you change
	the ISO setting on your camera, you adjust the sensitivity of the imager
	equivalent to the corresponding film sensitivity.
LCD	Liquid Crystal Display. Your camera has four: the Top Status LCD panel,
	Back Status LCD panel, Image LCD panel, and the LCD inside the viewfinder.
Manual flash	Flash output is controlled manually in manual flash mode, unlike in auto
	flash mode, where flash output power varies automatically according to the
	selected aperture. Some Speedlights provide selectable manual outputs
	(full, 1/2, 1/4, 1/8, 1/16, etc.), while others provide full manual output
	only.

April 29, 2004 Glossary-3