Photographic Glossary-N


Is a unit of measurement of light wavelength. A nanometer is one million of a millimeter.

A time measurement equal to one-billionth of a second.

ND Filter or Neutral Density Filter
A filter that attenuates light evenly over the visible light spectrum. It reduces the light entering a lens, thus forcing the iris to open to its maximum.

Neutral Density. Usually applies on filter, filtration that can effectively reduce the amount of light passes to the film. In some filters, half ND filters can be very effective to lower the contrast, esp the sky to achieve more balance effect. Lens like reflex lenses, where its aperture is fixed, ND filter can be the only way to play around with exposures. Certain 617 format is providing with a central ND filter.

Near ultraviolet
Are wavelength from about 400nm down to 250nm. Most photographic emulsions are sensitive to this range of bands.

Nearest neighbo r
Type of interpolation in which the value of the new pixel is an average of the neighboring pixels. Quick and dirty interpolation that gives rather ragged results.

Negative carrier
A frame that holds a negative flat in an enlarger.

Negative Holder
A device designed to hold the negative in proper position in an enlarger.

A photographic image which tonalities and colours are reversed from the original scene. Usually the film negative is used to make a positive print. The developed film that contains a reversed tone image of the original scene.

Neutral density filter
Describes a gray camera filter which has a equal opacity to all colours of the spectrum and so does not affect the colours in the final image. It is used to reduce the amount of light entering the camera when apertures or shutter must remain constant.

Newton rings
A series of concentric circles that appear on a scanned image when a thin layer of air exists between the glass scanner bed and the image being scanned. Newton rings appear when light waves are reflected from both top and bottom surfaces of the air between the glass and the image, interfering with the resulting scan.

Nicd or NICAD
Nickel Cadmium. Used as the backbone of most rechargeable batteries. Though not so lasting as alkaline, but have a better resistance to cold than alkaline. When the batteries power is drained out, it will turn "flat" right away (advisable to have spare batteries). Most high speed motor drive handles best when using Nicd batteries.

Nickel cadmium (NiCad)
Rechargeable batteries that use an alkaline electrolyte. They have a longer life than non-rechargeable batteries. NiCad batteries have a memory, so they need to be run all the way down before recharging. Otherwise, they will begin to run out of power sooner.

Nickel metal hydride (NiMH)
A rechargeable battery that lasts longer than a NiCad and has no memory, so it is easier to manage.

Nickel metal hydride. A new generation Nicd batteries, the Nikon highest speed 8 fps is achieved using this type of batteries.

Noise can be summarized as the visible effects of an electronic error (or interference) in the final image from a digital camera. Noise is a function of how well the sensor (CCD/CMOS) and digital signal processing systems inside the digital camera are prone to and can cope with or remove these errors (or interference).
Visible noise in a digital image is often affected by temperature (high worse, low better) and sensitivity (high worse, low better). Some cameras exhibit almost no noise and some a lot and all the time. It's certainly been the challenge of digital camera developers to reduce noise and produce a "cleaner" image, and indeed some recent digital cameras are improving this situation greatly, allowing for higher and higher ISO's to be used without too much noise.
Noise can also affect certain colour channels more than others, this is because a typical digital camera sensor (CCD/CMOS) is more sensitive to certain primary colours than others (often sensors are less sensitive to blue light) and so to compensate, these channels are amplified more than the others. Noise is also often amplified by the JPEG compression algorithm which reacts badly to a very noisy image (often introducing hue errors which weren't in the original noisy image). There are several techniques for cleaning a noisy image, and several products which have been developed to specifically perform this task.
Long Exposure "Stuck Pixels“ - Another type of noise often referred to as "stuck pixels" or "hot pixels" occurs only with long exposures (1-2 seconds or more) and appear as fixed coloured dots (slightly larger than a single pixel). Image compression without loss of quality.

Normal Lens
A lens that makes the image in a photograph appear in perspective similar to that of the original scene (approximately 45°). A normal lens has a shorter focal length and a wider field of view than a telephoto lens, and a longer focal length and narrower field of view than a wide-angle lens. Normal lenses corresponding to that portion of human vision in which we can discern sharp detail; technically defined as a lens whose focal length is approximately equal to the diagonal of the film frame; in 35mm photography, the diagonal measures 43mm, but in practice, lenses with focal lengths from 50mm to 60mm are considered normal. A lens with a focal length approximately the same as the diagonal measurement of the film being used. This produces an image that approximates the same angle of view and perspective of the human eye. For a 35mm camera, the 50mm lens is considered normal.

Notching code
Notches cut in the margin of sheet film so that the type of film and its emulsion side can be identified in the dark.

National Television Standards Committee. Standards for video broadcasting and recording in the US and Japan. PAL's the standard in Great Britain and the commonwealth countries. SECAM used in many countries in the European communities.