photography terms
Some digital cameras record the settings used to take each photo. An explanation of what each of the terms related to these settings means is available below.

Dimensions (Size)

The dimensions of the picture in pixels. Below is a table which gives approximate paper/photo sizes for different dimensions and resolutions. 72 pixels per inch (ppi) is the approximate resolution of your monitor. 150 ppi is perfect for a printer that can print 300-450 dots per inch (dpi), and 300 ppi is perfect for a 600-900 dpi printer.

Dimensions72 ppi150 ppi300 ppi
540×7208×10 in
(20×25 cm)
3.5×5 in
(9×13 cm)
768×102411×14 in
(28×36 cm)
5×7 in
(13×18 cm)
3×4 in
(8×10 cm)
1200×160018×24 in
(46×61 cm)
8.5×11 in
(22×28 cm)
4×6 in
(10×15 cm)
1536×204822×28 in
(56×71 cm)
11×14 in
(28×36 cm)
5×7 in
(13×18 cm)

Original Size

The dimensions of the photo straight from the camera.

Cropped Size

The dimensions of the photo after Photoshop tweaking and cropping. This is the largest size available for an exact enlargement of any photo in the gallery.


The opening in a camera lens through which light passes. Aperture size is calibrated in f-numbers - the larger the number, the smaller the lens opening. The f-number is the ratio of the lens diameter to the diameter of the aperture. For example, a 28mm camera at f/2 has an aperture 14mm across. Thus, for each multiple of 1.4, half the light reaches the CCD.

Aperture affects depth of field: the larger the f-number, the greater is the zone of sharpness.

Shutter speed

Length of time for which the shutter allows light to hit the CCD, in seconds.

Focal length

The distance between the CCD and the optical center of the lens when the lens is focused at infinity. This length is multiplied by a factor to express it in terms of a 35mm lens. Thus, a focal length of 70mm corresponds to a zoom of 2×.

Exposure mode

The fully automatic, semi-automatic, or manual method selected for determining aperture and shutter speed.

Aperture Priority

This mode allows the aperture to be fixed, while the shutter speed is adjusted automatically. Apart from the sport or action arena, aperture priority is the most common & effective automatic preference in photography.

Shutter Priority

This mode allows the shutter speed to be fixed, while the aperture is adjusted automatically. This is useful for taking pictures of movement, either to capture an instant or to show motion blur.

Metering mode

The method used to determine the appropriate aperture and/or shutter speed for automatic or semi-automatic exposure modes:


Exposure calculated by comparing measurements from 256 segments of the frame with a library of typical compositions, producing the best possible setting for entire frame.


Camera measures light in area in center of frame occupying roughly 1/32 of total. This allows compensation for extremely light or dark backdrops.


Camera measures lighting in entire frame, but assigns weight of 80% to area in center of frame occupying roughly 1/4 of total. This preserves background details while letting lighting conditions at center of frame determine exposure.

ISO equivalent

In a film camera, sensitivity is a characteristic of the film, not the camera. Sensitivity determines the amount of light needed to produce a given degree of exposure. The more sensitive the film, the less light needed to make an exposure, allowing higher shutter speeds. Higher sensitivity is achieved by altering the chemical composition of the film, causing a random pattern, called "grain," to appear in the final photograph. In a digital camera, sensitivity has a similar effect: higher sensitivities allow higher shutter speeds, at the expense of "noise" (the digital equivalent of film "grain") appearing in the final image.

ISO 100default, least noise
ISO 200twice as sensitive as ISO 100, more noise
ISO 400four times as sensitive as ISO 100, most noise