Bridge camera
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A bridge camera is a camera that combines the properties of single-lens reflex cameras and compact cameras, i.e. bridges the gap between the two construction principles in terms of equipment, quality and functional features. This type of camera is often called Prosumerkamera referred to its position between " pro fessional" - and "Con sumer " cameras to suggest.
The term “bridge camera” was coined in 1988 with the half-format Yashica Samurai camera and subsequent models from other manufacturers. The construction principle of the bridge cameras was initially also adopted for digital cameras.
With the widespread use of digital cameras, the term bridge camera has seen a change in meaning and refers to models in this area that are not trimmed for compactness, but are usually characterized by complex zoom lenses with a large zoom range and comparatively high light intensity, as well as manual functions in addition to the usual automatic functions Offer adjustment options. The presence of a hot shoe and a built-in electronic viewfinder system is also typical. With a few exceptions , the image sensor used has a relatively small format (smaller than e.g. Four-Thirds ).
Bridge cameras for 35mm film
Bridge cameras for 35mm film are single-lens reflex cameras with a built-in lens . This design principle has been around since the 1950s (e.g. Nikkorex 35), but was revived in 1988 with the Yashica Samurai. The built-in lens enables the use of a central lock and a somewhat more compact design. Because the lens can not be replaced, there is construction side, the possibility of using an active infrared - autofocus system's, although usually at the usual SLR passive phase detecting method, or a combination of the two methods was used.
Typical representatives of the 35mm bridge cameras are the Ricoh Mirai and Chinon GS-9. Olympus completely stopped the further development and production of its OM system in favor of the bridge cameras of the IS series. All of these 35mm bridge cameras corresponded in terms of equipment to entry-level SLR cameras.
Digital bridge cameras
The construction principle of the miniature bridge cameras was initially also adopted for digital bridge cameras, so these were also initially single-lens reflex cameras with a permanently installed lens. The first camera based on this principle was the Olympus Camedia C-1000L in 1997 . Other cameras from Olympus up to the E-20P from 2001 followed. Otherwise, only Pentax with the El-2000 (identical to the HP PhotoSmart 912 from Hewlett-Packard ) from 2000 followed this principle.
The SLR viewfinder was later replaced by an electronic viewfinder . In contrast to the monitor on the back of the camera, this can be seen easily even in strong ambient light. Similar to SLR cameras, it shows exactly the image section that is also recorded. However, manual focusing is difficult because of the comparatively low resolution of these viewfinders, and in low light these viewfinders produce a grainy, noisy image. Fast movements can also lead to streaks or jerky display.
advantages
Compared to a digital compact camera, a bridge camera is characterized by a zoom lens with usually a very large focal length range ; Lenses with a zoom factor of up to 125 × are used. The focal length range can - converted to the 35 mm format of 24 × 36 mm - reach up to 3000 mm in some cases (as of January 2020).
Due to their small sensors, bridge cameras can be equipped with relatively compact and powerful lenses. For example, the Panasonic Lumix DMC-FZ20 from 2004 with a sensor size of 5.76 × 4.29 mm has a twelve -fold zoom lens with a focal length of 36 mm to 432 mm (corresponding to 35 mm photography) and a largest aperture of aperture 1: 2.8 over the entire focal length range. An equivalent lens for a larger image sensor (such as a single lens reflex camera) would be optically much larger and heavier and cost several times as much, especially if it had to have the same light intensity with a focal length equivalent of around 400 mm. The sensor sizes of the bridge cameras are therefore the result of a compromise between handiness, zoom strength and price on the one hand, and image quality on the other.
While the zoom of digital compact cameras is usually operated by an electric motor using buttons or rockers, the larger construction of the bridge cameras allows much more sensitive zooming using the setting ring directly on the lens. Some models also offer a focus ring for manual focus adjustment or correction.
The advantage of bridge cameras over digital SLR cameras is the somewhat more compact design and the associated lower weight. The built-in LCD monitor also allows a live preview of the images - if the monitor can be swiveled, recordings can be made very conveniently close to the ground or overhead. Dark motifs can be electronically amplified on the monitor by the camera and thus displayed in an optimized way in terms of brightness and contrast, whereby this function is usually associated with a greatly increased image noise or a correspondingly lower frame rate . The possibility of displaying a histogram with the brightness distribution of the pixels in the electronic viewfinder or on the monitor before taking the picture is very useful in order to rule out incorrect exposures from the outset. These aids can now also be found on some digital SLR cameras.
Bridge cameras usually have - like compact cameras - a large number of so-called motif programs , which are adapted for typical shooting situations and are intended to simplify operation. However, as with SLR cameras, the values for the f-number and shutter speed as well as the sensitivity (ISO) can usually be set manually.
With the built-in lens, the camera forms a closed system, which is why the risk of contamination of the image sensor is considerably lower than with cameras with interchangeable lenses. The built-in lens also offers the possibility that the camera electronics can automatically correct some imaging errors of the lens at different focal lengths and apertures. SLR cameras are also increasingly offering such functions, but generally only for lenses from the housing manufacturer, but not for those from other manufacturers.
In contrast to older digital SLR cameras, almost all bridge cameras can also record videos in VGA format with sound and audio comments on photographs. Newer models also offer the option of recording videos in Full HD or Ultra HD up to 4K quality, with the option of choosing between different HD formats in some cases.
Most modern bridge cameras have optical image stabilization , in which a group of lenses in the lens or the image sensor is moved to compensate for camera shake.
Due to the lack of a mirror mechanism, bridge cameras can take almost completely noiseless recordings and there are no vibrations from the mirror impact.
When taking photos, no stray light can reach the camera's exposure sensor through the viewfinder, which in the case of single-lens reflex cameras may have to be prevented by an external or built-in eyepiece shutter or an eyepiece cover.
disadvantage
Compared to a SLR camera, the optical possibilities of a bridge camera are limited by the built-in zoom lens. With a few exceptions, the focal length range does not extend to the extreme wide angle, and the camera is very expensive even with a large focal length. Although wide-angle and teleconverters are offered, they are comparatively expensive, bulky and generally degrade the image quality.
Bridge cameras usually have a macro mode , but the setting options and image quality are limited compared to special macro lenses. In some cases, these restrictions can be circumvented by using close-up lenses , provided that they can be attached. However, quite a few bridge cameras lack a filter thread or a suitable adapter.
Even when taking photos with available light , it is often advantageous to use single-lens reflex cameras with larger image sensors and high-intensity fixed focal lengths, despite image stabilization. Compared to single-lens reflex cameras with a comparable image resolution, the image sensors used are much smaller and generate greater image noise , which can lead to almost unusable images at high sensitivity settings. One of the few exceptions for a long time was the no longer produced Sony DSC-R1 , which offered a full-fledged sensor in APS-C format. Since 2012, cameras with built-in lenses and comparatively large sensors have increasingly come onto the market, which, however, dispense with the large focal length ranges of classic bridge cameras in favor of compactness or even have lenses with a fixed focal length.
Along with the smaller size of the image sensor, the image scale (with the same focal length, a smaller section is shown, see format factor ) is lower than with digital SLR cameras. With a bridge camera, even with the maximum aperture, it is not possible to achieve such a shallow depth of field as with a single lens reflex camera with an equally wide aperture. This means a restriction of the compositional possibilities during the recording, since, for example, objects are more difficult to cut out or to separate foreground from background. Such effects then have to be created with the help of image processing in a much more complex manner. However, this effect is sometimes beneficial when taking close-up shots.
The other end of the aperture scale often extends further with single-lens reflex and system cameras than with bridge cameras: where the separate lenses of some can often be closed up to aperture 22, those with aperture 11 or even 8 stop. This is not enough to use the "motion blur" effect in bright sunlight, for example.
Since the image sensor and the viewfinder or monitor have to be switched on in order to display the subject, the result is a higher power consumption than with SLR cameras, which leads to a shorter operational readiness with one battery charge. As with compact cameras and single-lens reflex cameras with monitor previews ( live view ), the image noise is amplified by the heat generated in the image sensor, which can only be compensated for with restrictions, even by complex structural and electronic measures.
The low optical resolution of the built-in electronic viewfinder compared to SLR viewfinders makes manual focusing difficult. Most models try to compensate for this with the help of software enlargements on the monitor or in the electronic viewfinder, so an enlarged section of the entire area of the picture is displayed. The image sharpness is determined exactly in the sensor plane and not by a separate sharpness sensor, which on the one hand reduces problems with mechanical manufacturing tolerances, and on the other hand works noticeably slower than separate AF sensors with conventional image sensors with contrast autofocus. Since 2012, more and more cameras have come onto the market that have a phase autofocus integrated in the image sensor and thus achieve focusing speeds similar to digital SLR cameras.
