what do ISO mean for a cameras?

Answer 1

There are TWO definitions of ISO for cameras--one for film imaging, and one for digital imaging. Folks who define it as FILM speed are giving at best an incomplete definition.

They are both a measure of sensitivity to light, and define performance benchmarks that manufacturers have to meet. They are designed to be compatible, and each sensitivity value in the film ISO has an equivalent value in the digital imaging ISO, but they have their own distinct meanings and definitions.

For film, "ISO Standard 5800:1987" is the standard that defines the nomenclature for film speed performance--how long it takes a particular film emulsion to properly expose an image, given a fixed amount of light. For Digital Imaging, ISO Standard 12232:2006 defines ISO an imaging sensor's speed in terms of the amount of light needed to achieve a certain per-pixel signal-to-noise ratio. The basis of how the nomenclature is defined varies, as you can see, based on it's underlying technology.

The standards are defined by the International Organization for Standardization (ISO), which writes standards for all sorts of industries, like defining steel hardness nomenclature, telephone call protocals, even down to defining what an inch is. So "ISO" in the photographic sense is just one of the thousands of standards documents these guys write.

A standard is defined for film speed for the same reason that a standard is defined for an inch, or a meter. If everyone had different definitions for what a meter is, then it would be hard for anyone to know which definition is meaningful. With a clear definition in place, we all know what to expect when someone says they offer ISO 3200 performance. Of course, manufacturers push the limits of what can be called ISO 3200. But at least someone has a reference point to see how much they are stretching the truth.

Answer 2

ISO sensitivity expresses the speed of photographic negative materials (formerly expressed as ASA).

Since digital cameras do not use film but use image sensors instead, the ISO equivalent is usually given.

What ISO denotes is how sensitive the image sensor is to the amount of light present. The higher the ISO, the more sensitive the image sensor and therefore the possibility to take pictures in low-light situations.

Read more here:
http://www.photoxels.com/tutorial_iso.html

Answer 3

Film speed is a standardized way of measuring the light sensitivity of a certain film or digital capture device. The terms ASA (American Standard Association) and ISO (International Standards Organization) are the standards by which we measure the light sensitivity. The higher the ISO, the more sensitive the film or device is to light.

Answer 4

For a ordinary factor and shoot digital camera (no longer DSLR) taking images outdoors in staggering image voltaic you would possibly want to pick your ISO putting as low as might want to be reckoning on the digital camera. some go as low as sixty 4, or 80, or one hundred. As gentle receives dimmer you advance ISO putting to both three hundred, or four hundred. As a minimum of one answerer reported because a digital camera's ISO form is going to 1600, it truly is all hype. it really is a ineffective shot at that form, extremely blurry. some cameras, yet no longer very many help you to shoot larger than a four hundred ISO, yet oftentimes do not go over four hundred on a level and shoot digital camera. So, ISO is your digital camera's sensitivity to gentle.

Answer 5

Wikipedia:
"The standard known as ISO 5800:1987 from the International Organization for Standardization (ISO) defines both a linear scale and a logarithmic scale for measuring film speed."

Simply, the ISO rating is a standardized scale for determining how quickly film reacts to light, better known as film speed.

Higher numbers mean faster films, which are better for capturing high action images and photos taken with flashes. 400 and 800 speed films are common, relatively high-speed films for most point-and-shoot film cameras, though higher speeds exist. These films typically perform better in low-light situations, as more of the image is recorded in less time. However, they tend to produce granier images.

Lower-speed films are better for brighter-lit, slower-action images, like portraits and some nature photography. They can better handle longer exposures without becoming washed out. 100 and 200 speed films are common low-speed consumer films. They also tend to create fine-grained, or less grainy, images.

Answer 6

Film speed is the measure of a photographic film's sensitivity to light. Stock with lower sensitivity (lower ISO speed rating) requires a longer exposure and is thus called a slow film, while stock with higher sensitivity (higher ISO speed rating) can shoot the same scene with a shorter exposure and is called a fast film.

Answer 7

<>ISO sensitivity expresses the speed of photographic negative materials (formerly expressed as ASA).
Since digital cameras do not use film but use image sensors instead, the ISO equivalent is usually given.
More info:
http://www.digicamhelp.com/camera-features/advanced-settings/iso.php

Answer 8

I think it means film speed...I could be wrong though!