Frame Counter and Film-Load Reminder
The frame counter located in the hub of the film-advance lever shows the number of frames which have been exposed. lt resets itself automatically to two frames before zero when the camera back is removed. There are red indicators for numbers 0, 20 and 36, and the frame counter stops at the 36 mark. The filmload reminder opposite the frame counter is set manually by means of an indicator pin to serve as a reminder of the numberof exposures on the film in the camera.
Film-Speed Reminder Dial
The film-speed reminder dial is located on the camera baseplate. lt can be set manually to indicate the type of film (color or black-and-white) and ASA rating of the film loaded in the camera. “E” represents empty.
Film-Plane lndicator
The exact position of the film plane can be determined by picturing an imaginary line drawn along the top edge of the digits which make up the camera serial number. This is important to know when measuring the film-to-subject distance, especially in close-ups and macrophotography.
Film-Advance Lever
The film-advance lever advances the film, cocks the shutter and operates the frame counter with a single strake of 136° or with a series of short strokes. A built-in safety device prevents the shutter from being released until it is fully cocked. The lever is designed so that it springs back when released but does not strike the camera body.
A 15° angle of clearance allows the thumb to be inserted for easy, comfortable film advancing. The lever folds flat on top of the camera for storage in the eveready case.
SELECTINGT THE SHUTTER SPEED
The numbers on the shutter speed dial stand for fractions of a second. 125 represents 1/125 second and so forth. At the B (Bulb) setting, the shutter remains open as long as the shutter release button is held down. The Nikon F also has a T (Time) setting; at this setting, the shutter will remain open until it is closed manually by rotating the shutter speed dial one dick stop in either direction. To set the shutter speed, turn the shutter speed dial until the desired number clicks into position opposite the black dot to the
left of the shutter speed dial between the dial and the viewfinder. The dial is clickstopped to rotate a full 360° in either direction, before or after the shutter is wound. The shutter release button is threaded to accept the Nikon F cable release.
In the center of the shutter speed dial beneath a transparent window is a small black dot which indicates whether or not the shutter is cocked; in the cocked position, the dot lines up with the shutter speed in use. When the shutter is released, the dot returns to the 7 o’clock position.
A pin on top of the shutter speed dial permits direct coupling with the Photomic-series finders.
For convenience when using flashbulbs or electronic flash, the shutter speed markings are color-coded to match the markings on the synchronization selector located under the transparent window just above the selector ring. For details refer to the chapter on flash synchronization (page 26 ).
SETTING THE APERTURE
To preset the lens aperture, turn the knurled aperture ring on the lens barre! until the desired f/number lines up with the black dot in the top center of the milled ring. The diaphragm can also be preset for intermediate apertures between the click-stopped
Aperture and Depth of Field
The lens aperture determines the amount of light which passes through the lens and strikes the film. lt also influences depth of field. Apertures are expressed in f/numbers, with larger numbers representing smaller apertures. For example, f/4 is larger than f/8 and allows more light to reach the film. Each f/number admits exactly twice as much light as the next largest number, so when the aperture is increased or decreased by one stop, the exposure time required is doubled or halved respectively. For example:
Depth of field refers to a zone extending in front of and behind the plane of sharpest focus. Within this zone, blur (or unsharpness of the image) will be negligible and everything can be accepted as being in sharp focus. lt extends a greater distance behind the subject in focus than in front. Depth of field depends on three factors: focal length of the lens, lens-to-subject distance and taking aperture. The smaller the aperture and the shorter the focal length of the lens, the greater the depth of field (for example, wideangle lenses have more depth of field than telephotos). Also, the closer the subiect, the smaller the depth of field. These three factors can be adjusted independently or in combination to give the photographer creative control over the final picture. By stopping down the lens only, the depth of field can be increased, as illustrated by the following three photographs:
1. Lens at f/ 4. Small depth of field with only main subject in focus.
Using the Depth-of-Field Preview Button
The depth of field at taking aperture can be seen by depressing the depth-of-field preview button located on the front of the camera. When the button is pressed, the diaphragm closes down to the preselected taking aperture and the exact conditions of taking aperture and allows you to see how much background or foreground is in or out of focus. Depth of field can also be determined by referring to the color-coded scale
printed on the Jens barre!. The colored lines on either side of the main index mark (black arrow) correspond to different f/numbers which are engraved in corresponding colors. With the Jens focused on a subject and set for a preselected aperture, depth of field can be read from the distance scale. For example, with the 50mm f/1.4 Jens focused at 15 feet (4.5m) and used at a taking aperture of f/16, depth of field extends from approximately 8 feet (2.4m) to infinity (00).
Caution: Do not release the shutter while the depth-of-field preview button is held down as this may result in the reflex mirror remaining in the locked-up position. If this should happen, the mirror will not return to its original focusing and viewing position until after one extra exposure has been made.