Fixed-lens cameras
Non-SLR digital cameras generally fall into two types: compact digicams, and SLR-like bridge digital cameras (also known as advanced digital cameras) which offer larger zoom ranges, better optics, and more manual controls. Both types have permanently fixed lenses. While the only defining feature of an SLR is its reflex viewfinder system, extant digital SLR models generally offer the following advantages over fixed-lens cameras of the same generation:- Choice of interchangeable[35] (and often higher-quality) lenses.
- Image sensors of much larger size and often higher quality, offering lower noise,[36] which is useful in low light, and greater dynamic range.[37]
- Optical viewfinders which tend to be more comfortable and efficient, especially for action photography and in low-light conditions.
- DSLRs often offer faster and more responsive performance, with less shutter lag, faster autofocus systems, and faster frame rates.[38]
- The larger focal length for the same field of view allows creative use of depth of field effects.[39]
- Ability to attach additional accessories[40] including hot shoe-mounted flash units, battery grips for additional power and hand positions, external light meters, and remote controls
- Generally greater size and weight.[41]
- Generally greater cost.[41]
- Few DSLRs produced so far can record video,[41] although many newer DSLR designs such as the Canon EOS 550D, Canon EOS 7D, Nikon D90, Nikon D7000, Nikon D3s and the Canon EOS 5D Mark II[42] do have this ability.
- Louder operation, due to the SLR mirror mechanism.[43]
- Potential contamination of the sensor by dust particles, when the lens is changed (though recent dust reduction systems alleviate this).
- Small digicams generally can focus better on closer objects than typical DSLR lenses.[44]
SLR-like cameras – "bridge cameras"
Main article: Bridge digital camera
The "SLR-like" or "advanced" digicams offer a non-optical electronic through-the-lens (TTL) view through the focusing lens, via the eye-level electronic viewfinder (EVF) as well as the rear LCD. The difference in views compared to a DSLR is that the EVF shows a digitally-created TTL image, whereas the viewfinder in a DSLR shows an actual optical TTL image via the reflex viewing system. An EVF image has lag time (that is, it reacts with a delay to view changes and has a lower resolution than an optical viewfinder) but achieves parallax-free viewing using less bulk and mechanical complexity than a DSLR with its reflex viewing system.Bridge digital cameras with their fixed lenses aren't usually subject to dust from outside the camera settling on the sensor. However having fixed lenses they are limited to the focal lengths they are manufactured with, except for what is available from attachments. Manufacturers have attempted (with increasing success) to overcome this disadvantage by offering extreme ranges of focal length on models known as superzooms, some of which offer far longer focal lengths than readily available DSLR lenses.
Current designs are limited by increasingly high pixel pitches, which limit their dynamic range and also call for increasingly higher quality lens designs. Exceptions to this trend are the Sigma DP1 with its 20.7×13.8 mm sensor and the Sony DSC-R1[45] with a 21.5×14.4 mm sensor.
Digicams (compact "point-and-shoot" digital cameras)
Digicams, commonly referred to as "point-and-shoot" cameras because of their ease of use, can usually be operated at arm's length using only the LCD at the rear of the camera. Some models also have simple optical viewfinders like traditional compact 35 mm film cameras. Like the SLR-like bridge cameras, most digicams lack the ability to accept interchangeable lenses, with the exception of certain digital rangefinder cameras such as the Leica M8 and the Epson RD-1, which use the Leica M-mount lens system.Most digicams are manufactured with a zoom lens that covers the most commonly used fields of view, with "super-zoom" models becoming more popular. Digicam lenses can be adapted to telephoto or wide-angle as the above-mentioned "bridge-cameras."
Digicams were once significantly slower in image capture (time measured from pressing the shutter release to the writing of the digital image to the storage medium) than DSLR cameras, but this situation is changing with the introduction of faster capture memory cards and faster in-camera processing chips. Currently, however, these cameras present a significant disadvantage for action, wildlife, sports and other photography requiring a high burst rate (frames per second).
SLR-like interchangeable lens digital cameras
Main article: Mirrorless interchangeable lens camera
In late 2008, the Micro Four Thirds system became the latest camera system to compete with DSLRs. The new system shares the same sensor size as the original Four Thirds System, but does not use a mirror system and is therefore able to reduce the focal-distance between the lens and sensor. Micro Four Thirds cameras substitute an electronic viewfinder with the same eye level relief, mimicking the viewfinder operation of DSLRs. All four thirds cameras also feature a rear LCD-screen, which serves as both a live-preview and playback monitor. Panasonic released the first Micro Four Thirds camera, the Lumix DMC-G1, and later released the Lumix DMC-GH1, which added a Full-HD movie-mode (1080, 24p). Several manufacturers have announced lenses for the new Micro Four Thirds mount, while older Four Thirds lenses can be mounted with an adapter (a mechanical spacer with front and rear electrical connectors and its own internal firmware).A similar mirror-less interchangeable lens camera, but with an APS-C-sized sensor, was announced in January 2010: the Samsung NX10.
A handful of rangefinder cameras support interchangeable lenses. Three digital rangefinders exist, they are the Epson R-D1 (APS-C-sized sensor), the Leica M8 (APS-H-sized sensor), both smaller than 35 mm film rangefinder cameras, and the Leica M9, which is a full-frame camera.
Digi Camera
DSLR
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