f stops demonstrated on a lens

The aperture stop of a photographic lens can be adjusted to control the amount of light reaching the film or image sensor. In combination with variation of shutter speed, the aperture size will regulate the film’s or image sensor’s degree of exposure to light. Typically, a fast shutter speed will require a larger aperture to ensure sufficient light exposure, and a slow shutter speed will require a smaller aperture to avoid excessive exposure.

A device called a diaphragm usually serves as the aperture stop, and controls the aperture. The diaphragm functions much like the iris of the eye – it controls the effective diameter of the lens opening. Reducing the aperture size increases the depth of field, which describes the extent to which subject matter lying closer than or farther from the actual plane of focus appears to be in focus. In general, the smaller the aperture (the larger the number), the greater the distance from the plane of focus the subject matter may be while still appearing in focus.

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Steve Jobs and Steve Wozniak had withdrawn from Reed College and UC Berkeley, respectively by 1975. Wozniak designed a video terminal that he could use to log on to the minicomputers at Call Computer. Alex Kamradt commissioned the design and sold a small number of them through his firm. Aside from their interest in up-to-date technology, the impetus for “the two Steves” seems to have had another source. In his essay From Satori to Silicon Valley (published 1986), cultural historian Theodore Roszak made the point that the Apple Computer emerged from within the West Coast counterculture and the need to produce print-outs, letter labels, and databases. Roszak offers a bit of background on the development of the two Steves’ prototype models.

In 1975, Wozniak started attending meetings of the Homebrew Computer Club. New microcomputers such as the Altair 8800 and the IMSAI inspired him to build a microprocessor into his video terminal and have a complete computer.
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A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier (URI) and may be a web page, image, video, or other piece of content. Hyperlinks present in resources enable users easily to navigate their browsers to related resources. A web browser can also be defined as an application software or program designed to enable users to access, retrieve and view documents and other resources on the Internet.

Although browsers are primarily intended to access the World Wide Web, they can also be used to access information provided by web servers in private networks or files in file systems. The major web browsers are Firefox, Google Chrome, Internet Explorer, Opera, and Safari.

History

The first web browser was invented in 1990 by Tim Berners-Lee. It was called WorldWideWeb (no spaces) and was later renamed Nexus.

In 1993, browser software was further innovated by Marc Andreesen with the release of Mosaic (later Netscape), “the world’s first popular browser”, which made the World Wide Web system easy to use and more accessible to the average person. Andreesen’s browser sparked the internet boom of the 1990s.

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Adobe’s first products after PostScript were digital fonts, which they released in a proprietary format called Type 1. Apple subsequently developed a competing standard, TrueType, which provided full scalability and precise control of the pixel pattern created by the font’s outlines, and licensed it to Microsoft. Adobe responded by publishing the Type 1 specification and releasing Adobe Type Manager, software that allowed WYSIWYG scaling of Type 1 fonts on screen, like TrueType, although without the precise pixel-level control. But these moves were too late to stop the rise of TrueType. Although Type 1 remained the standard in the graphics/publishing market, TrueType became the standard for business and the average Windows user. In 1996, Adobe and Microsoft announced the OpenType font format, and in 2003 Adobe completed converting its Type 1 font library to OpenType.

In the mid-1980s, Adobe entered the consumer software market with Adobe Illustrator, a vector-based drawing program for the Apple Macintosh. Illustrator, which grew from the firm’s in-house font-development software, helped popularize PostScript-enabled laser printers. Unlike MacDraw, then the standard Macintosh vector drawing program, Illustrator described shapes with more flexible Bézier curves, providing unprecedented accuracy. Font rendering in Illustrator, however, was left to the Macintosh’s QuickDraw libraries and would not be superseded by a PostScript-like approach until Adobe released Adobe Type Manager.

In 1989, Adobe introduced what was to become its flagship product, a graphics editing program for the Macintosh called Photoshop. Stable and full-featured, Photoshop 1.0 was ably marketed by Adobe and soon dominated the market.

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