Gambar foto
Gambar foto (seringnya disingkatkan menjadi foto) ialah imej yang dicipta oleh cahaya yang jatuh pada permukaan peka cahaya, biasanya filem fotografi atau pengimej elektronik seperti peranti caj terganding (CCD) atau cip semikonduktor oksida logam pelengkap (CMOS). Kebanyakan gambar foto dicipta oleh kamera yang menggunakan kanta untuk memfokus panjang gelombang cahaya nampak bagi sesuatu pemandangan menjadi salinan yang dapat dilihat dengan mata manusia. Proses dan amalan untuk mencipta gambar foto dikenali sebagai fotografi. Perkataan "fotograf" dicipta oleh Sir John Herschel pada 1839, berdasarkan perkataan Greek, φώς (phos), "cahaya" + γραφίς (graphis), "stilus", "kuas" atau γραφή (graphê), "perlambangan menerusi garis" atau "lukisan", dan bersama-sama membawa pengertian "melukis dengan cahaya".[1]
Sejarah
The first permanent photograph was made in 1825 by a French inventor, Joseph Nicéphore Niépce, building on a discovery by Johann Heinrich Schultz (1724): that a silver and chalk mixture darkens under exposure to light. Niépce and Louis Daguerre refined this process. Daguerre discovered that exposing the silver first to iodine vapor, before exposure to light, and then to mercury fumes after the photograph was taken, could form a latent image; bathing the plate in a salt bath then fixes the image. These ideas led to the famous daguerreotype.
The daguerreotype had its problems, notably the fragility of the resulting picture, and that it was a positive-only process and thus could not be re-printed. Inventors set about looking for improved processes that would be more practical. Several processes were introduced and used for a short time between Niépce's first image and the introduction of the collodion process in 1848. Collodion-based wet-glass plate negatives with prints made on albumen paper remained the preferred photographic method for some time, even after the introduction of the even more practical gelatin process in 1871. Adaptations of the gelatin process have remained the primary black-and-white photographic process to this day, differing primarily in the film material itself, originally glass and then a variety of flexible films.
Color photography is almost as old as black-and-white, with early experiments dating to John Herschel's experiments with Anthotype from 1842, and Lippmann plate from 1891. Color photography became much more popular with the introduction of Autochrome Lumière in 1903, which was replaced by Kodachrome, Ilfochrome and similar processes. For many years these processes were used almost exclusively for transparencies (in slide projectors and similar devices), but color prints became popular with the introduction of the Chromogenic negative, which is the most-used system in the C-41 process. The needs of the movie industry have also introduced a host of special-purpose systems, perhaps the best-known being the now rare Technicolor.
Jenis gambar foto
Non-digital photographs are produced with a two-step chemical process. In the two-step process the light-sensitive film captures a negative image (colors and lights/darks are inverted). To produce a positive image, the negative is most commonly transferred ('printed') onto photographic paper. Printing the negative onto transparent film stock is used to manufacture motion picture films.
Alternatively, the film is processed to invert the negative image, yielding positive transparencies. Such positive images are usually mounted in frames, called slides. Before recent advances in digital photography, transparencies were widely used by professionals because of their sharpness and accuracy of color rendition. Most photographs published in magazines were taken on color transparency film.
Originally all photographs were monochromatic, or hand-painted in color. Although methods for developing color photos were available as early as 1861, they did not become widely available until the 1940s or 50s, and even so, until the 1960s most photographs were taken in black and white. Since then, Color photography has dominated popular photography, although black and white is still used, being easier to develop than color.
Panoramic format images can be taken with cameras like the Hasselblad Xpan on standard film. Since the 1990s, panoramic photos have been available on the Advanced Photo System film. APS was developed by several of the major film manufacturers to provide a film with different formats and computerized options available, though APS panoramas were created using a mask in panorama-capable cameras, far less desirable than a true panoramic camera which achieves its effect through wider film format. APS has become less popular and is being discontinued.
The advent of the microcomputer and digital photography has led to the rise of digital prints. These prints are created from stored graphic formats such as JPEG, TIFF, and RAW. The types of printers used include inkjet printers, dye-sublimation printer, laser printers, and thermal printers. Inkjet prints are sometimes given the coined name "Giclée".
Mitos dan kepercayaan
Since daguerreotypes were rendered on a mirrored surface, many spiritualists also became practitioners of the new art form. Spiritualists would claim that the human image on the mirrored surface was akin to looking into one's soul. The spiritualists also believed that it would open their souls and let demons in. Aborigines believed that taking one's picture took part of one's soul away.
Isu undang-undang
Undang-undang tentang pornografi kanak-kanak, pornografi melampau, dan sebagainya sering lebih menyekat gambar foto dan filem daripada perbuatan yang digambarkan, iaitu gambar foto dan filem tentang perbuatan yang sah mungkin menyalahi undang-undang.
Lihat juga
| Wikimedia Commons mempunyai media berkaitan Gambar foto |
| Cari photograph dalam Wikikamus bahasa Melayu, kamus bebas. |
Rujukan