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Iris Folding
Iris folding is a paper craft technique that involves folding strips of colored paper in such a way to form a design. The center of the design forms an ''iris''—a shape reminiscent of the iris diaphragm of a camera lens. History Iris folding originated in 20th-century Holland, where early craft people made their designs using patterned paper cut from the inside of envelopes. Techniques Iris folding is done with a pattern. The crafter uses the finished product to decorate the front of a greeting card A greeting card is a piece of card stock, usually with an illustration or photo, made of high quality paper featuring an expression of friendship or other sentiment. Although greeting cards are usually given on special occasions such as birthday ..., as a scrapbook embellishment, to decor a pattern, strips of colored paper, permanent transparent tape, cutting tools and a temporary tape such as painters tape. The temporary tape is used to hold the pattern in place while the crafts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diaphragm (optics)
In optics, a diaphragm is a thin opaque structure with an opening (aperture) at its center. The role of the diaphragm is to ''stop'' the passage of light, except for the light passing through the ''aperture''. Thus it is also called a stop (an aperture stop, if it limits the brightness of light reaching the focal plane, or a field stop or flare stop for other uses of diaphragms in lenses). The diaphragm is placed in the light path of a lens or objective, and the size of the aperture regulates the amount of light that passes through the lens. The centre of the diaphragm's aperture coincides with the optical axis of the lens system. Most modern cameras use a type of adjustable diaphragm known as an iris diaphragm, and often referred to simply as an iris. See the articles on aperture and f-number for the photographic effect and system of quantification of varying the opening in the diaphragm. Iris diaphragms versus other types A natural optical system that has a diaphragm an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camera Lens
A camera lens (also known as photographic lens or photographic objective) is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically. There is no major difference in principle between a lens used for a still camera, a video camera, a telescope, a microscope, or other apparatus, but the details of design and construction are different. A lens might be permanently fixed to a camera, or it might be interchangeable with lenses of different focal lengths, apertures, and other properties. While in principle a simple convex lens will suffice, in practice a compound lens made up of a number of optical lens elements is required to correct (as much as possible) the many optical aberrations that arise. Some aberrations will be present in any lens system. It is the job of the lens designer to balance these and produce a desi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pattern
A pattern is a regularity in the world, in human-made design, or in abstract ideas. As such, the elements of a pattern repeat in a predictable manner. A geometric pattern is a kind of pattern formed of geometric shapes and typically repeated like a wallpaper design. Any of the senses may directly observe patterns. Conversely, abstract patterns in science, mathematics, or language may be observable only by analysis. Direct observation in practice means seeing visual patterns, which are widespread in nature and in art. Visual patterns in nature are often chaotic, rarely exactly repeating, and often involve fractals. Natural patterns include spirals, meanders, waves, foams, tilings, cracks, and those created by symmetries of rotation and reflection. Patterns have an underlying mathematical structure; indeed, mathematics can be seen as the search for regularities, and the output of any function is a mathematical pattern. Similarly in the sciences, theories explain and predict reg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greeting Card
A greeting card is a piece of card stock, usually with an illustration or photo, made of high quality paper featuring an expression of friendship or other sentiment. Although greeting cards are usually given on special occasions such as birthdays, Christmas or other holidays, such as Halloween, they are also sent to convey thanks or express other feelings (such as condolences or best wishes to get well from illness). Greeting cards are usually packaged with an envelope and come in a variety of styles. There are both mass-produced and handmade versions available and they may be distributed by hundreds of companies large and small. While typically inexpensive, more elaborate cards with die-cuts, pop-ups, sound elements or glued-on decorations may be more expensive. Hallmark Cards and American Greetings, both U.S.-based companies, are the two largest producers of greeting cards in the world today. In Western countries and increasingly in other societies, many people tradit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
