Bridge cameras are cameras which fill the niche between the single-lens reflex cameras (SLRs) and the Point-and-shoot camera.[1][2] They are often comparable in size and weight to the smallest Digital SLRs (DSLR), but almost all digital bridge cameras lack an optical viewfinder system (film bridges generally had a lighter version of a reflex finder). In addition, SLRs normally feature interchangeable lenses, while current bridge cameras do not.[3] The phrase has been in use at least since the 1980s,[1] and continues to be used with digital cameras.[2] The term "Bridge camera" was originally used to refer to film cameras which "bridged the gap" between point-and-shoot cameras and SLRs.[4][5]
Like other cameras, most current bridge cameras are digital. These cameras typically feature full manual controls over shutter speed, aperture, ISO, white balance and metering. Generally, their feature sets are similar to consumer DSLRs, except for a smaller range of ISO sensitivity because of their typically smaller image sensor (a DSLR has a 35mm, APS, or 4/3 size CCD or CMOS). Many bridge cameras have long zoom lenses, so the term "bridge camera" is often used interchangeably with "megazoom", "superzoom", or "ultrazoom."[6] However, some bridge cameras have only moderate or short zooms (such as the Canon Powershot G9[7]), while many compact cameras have superzoom lenses but lack the advanced functions of a bridge camera.
With zoom ranges and sales rapidly increasing in the early 21st century, every major camera manufacturer has at least one 'super zoom' in their lineup.[8]
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Bridge cameras typically have small image sensors, allowing their lenses also to be smaller than a 35mm or APS-C SLR lens covering the same zoom range. As a result, very large zoom ranges (from wide-angle to telephoto, including macro) are feasible with one lens. The typical bridge camera has a telephoto zoom limit of over 400mm (35mm equivalent), although some 21st century cameras reach over 500mm.[9] For this reason, bridge cameras typically fall into the category of superzoom cameras.[10]
A typical example is the 24× Zoom Nikkor ED 4.6-110.4mm f2.8-5.0 on the Nikon Coolpix P90, which in 35 mm equivalent focal length terms is a 26-624mm.[11] To reduce aberration in a lens with such ambitious specifications, these have quite complex constructions, using multiple aspheric elements and often anomalous-dispersion glass. In this example pincushion- and barrel distortion can be corrected in the camera firmware as well. The ability to fit such a wide zoom range in one single small-diameter lens makes lens interchangeability redundant for most photographers. However, most bridge cameras allow the use of secondary lenses to improve wide angle, telephoto or macro capabilities. These secondary lenses typically screw onto the front of the primary lens either directly or by use of an adapter tube.
Bridge cameras employ two types of electronic screens as viewfinders: The LCD and the electronic viewfinder (EVF). All bridge cameras have an LCD with live-preview and usually in addition either an EVF or an optical viewfinder (OVF) (non-parallax-free, as opposed to the OVF of DSLRs, which is parallax-free). A high-quality EVF is one of the advanced features that distinguish bridge cameras from consumer compact cameras.
All DSLRs, by definition, have a through-the-lens OVF. Newer DSLR models typically also allow 'live view' on the LCD screen as an alternative to the OVF.
The EVF of bridge cameras, and the LCD of bridge cameras and DSLRs in 'live view' mode; continuously show the image generated by the sensor. The continuous digitally-generated live view has some advantages and disadvantages compared to the optically-generated view through the OVF of DSLRs. One advantage is that the digital preview is affected by all shooting settings and thus the image is seen as it will be recorded (in terms of things like exposure, white balance, grain-noise, etc) which the OVF of DSLRs is incapable of showing.[12] Another advantage is facilitating the framing from difficult angles by making the LCD movable (vari-angle). The LCD and EVF normally show 100% of the image while previewing (WYSIWYG). The OVF of professional DSLRs normally shows 100% of the image, but the OVF of consumer DSLRs may show slightly less than 100%.
The electronic screens of bridge cameras do not work as well as the OVF of DSLRs in situations of low light, or in bright daylight where the LCD screen might be difficult to see and use for framing. Also the screen has low resolution and refresh rate compared to the very high resolution and instantaneous refresh provided by an optical path in the OVF of DSLRs. Low resolution impedes manual focusing, but most modern bridge cameras implement a method that automatically magnifies a central frame within the screen (manual focus point) to allow easier manual focusing. A slow refresh rate means that the image seen on the screen will have a fraction of a second lag or delay from the real scene being photographed. The electronic screens used in modern bridge cameras are gradually improving in their size, resolution, visibility, magnification and refresh rate.
Continuous operation of the sensor shortens battery life and raises temperature. A DSLR's sensor (when not in live view mode) only operates when the shutter is open, and the electronic screen is typically off more, causing less battery drain. In bright conditions the light impinging constantly on the sensor of a non-SLR so it can show the image can heat the sensor, increasing image noise; in a DSLR, the sensor is exposed to light only during the fraction of a second that the shutter is open.
Examples of bridge cameras are the Nikon Coolpix P90 2009 model with 24× Optical Zoom NIKKOR lens, some Canon PowerShot S and Fujifilm FinePix S-series cameras, Olympus SP-500 Ultra Zoom, Olympus SP-570UZ, and the Panasonic Lumix DMC-FZ50. The Casio Exilim Pro EX-F1 could also be considered a bridge camera, though its video features distinguish it from any other consumer camera. Kodak EasyShare P-Series and Z-Series. Minolta (before the Konica Minolta merger) marketed the DiMAGE series, with the Minolta GT manual fixed zoom lens. Their bridge digital cameras were known as ZSLRs (zoom lens, single lens reflex). Olympus was the first to place a 20x zoom on a bridge camera with the Olympus SP-570.
The Sony DSC-R1 (2005–2006) and the Sigma DP1 (2008) are bridge cameras with APS size imaging sensors. The DP1 is much smaller than typical bridge cameras, and has a fixed focal length (non-zoom) lens. Current superzoom model from Sony is CyberShot DSC HX1,[13] which replaced the CyberShot DSC H50.[14] The HX1 has a CMOS sensor, which is very rare for non-DSLR cameras. The Nikon Coolpix P6000,[15] Canon PowerShot G series,[16][17] and Panasonic LX-3 are other examples of smaller bridge cameras with smaller zoom ranges.[18]
Most bridge cameras have flash arrangements similar to compact cameras. Few have an external hot shoe as Kodak Z980 has and also Panasonic Lumix DMC-FZ50, and the newer Kodak Z981 has none.[19] Only three non-DSLRs in Canon's current lineup offer the facility for external flashguns, i.e. two for Bridge Camera and one for Compact Camera: PowerShot SX1 IS, SX30 IS (has hidden hotshoe) as replacement of SX20 IS and G11, respectively.[20] Most of bridge camera have PSAM (Program, Shutter Speed, Aperture, Manual) mode besides Auto mode as DSLR have.
Introduced in 2010 the Fujifilm FinePix HS10 is larger and heavier than most EVF cameras, and has a 30x optical zoom.[21][22][23]
The closest rival of the most complete camera Fujifilm FinePix HS10 is Panasonic Lumix DMC-FZ100. Differences of both cameras are minor. The main features/specifications is 9.8 MP CMOS sensor true resolution or 14.0 MP native resolution (same size sensor with Fujifilm FinePix HS10), only 24x optical zoom (25mm-600mm) plus digital zoom 4x, RAW, Full AVCHD Stereo 1920x1080 at 30 frame/s, high speed video capture 320x240 at 220frame/s, Have external hot shoe, Continuous shooting 11 frame/s, Have Lens Thread.[24]
At CES 2011, Fujifilm announced FinePix HS20EXR as a successor of HS10EXR, but not as a successor of Fujifilm FinePix HS10 which has no EXR processor. It is provided with 16 MP EXR-CMOS sensor with new EXR processor for speed and better behaviour in low-light condition. Optical zoom 30x (24-720mm in 35mm equivalent). It is also Full HD 1080p with High Speed Movie option up to 320 frame/s. RAW and RAW+JPEG. The motion panorama can take picture in 360 degrees horizontally or vertically. It has availabled since late March 2011.[25] Motorized and manual zooming, has hot shoe and has filter threads.
Nikon P500 has the longest optical zoom at 36x (22.5mm wide angle to 810mm telephoto) and also the widest wide angle bridge camera. It has a 12 MP CMOS sensor, but has no lens threads.[26]
Sony DSC-HX100V has 16.2 MP CMOS sensor (equivalent with Fujifilm HS20EXR), 30x optical zoom (27-810 mm equivalent), 7x digital zoom and video Full HD 1080p - 60 frame/s, but no hotshoe and no lens thread.[27]
Canon PowerShot SX30 IS has the second longest optical zoom at 35x with 4.5 stops lens stabiliser camera plus 4x digital zoom will cover 24-3360mm (eq. 35mm film camera). Has 14.1 MP CCD sensor, but only has HD movies 720p30 stereo. [28] The camera seems as replacement of Canon PowerShot SX20 IS which has 12.1 MP CCD sensor and also only HD movies 720p30. Certainly not exactly as replacement of Canon PowerShot SX1 IS which has 10.0 MP CMOS fast/reactive sensor and also Full HD movies 1920x1080 at 30 frame/s stereo.[29][30] Available in September 2011, the successor Canon PowerShot SX40 HS (not IS) use HS System to boost low-light performance with 12.1MP CMOS sensor powered by the new Digic 5 image processor and capable to take video Full HD 1080p. The body and the lens is same with the predecessor Canon PowerShot SX30 IS.[31]
At CES 2011, Fujifilm also announced 4 S-Series. All have 14 MP CCD sensor and only capable of HD 720p movies, but allow zooming while taking video with sound. Allows up to 8 fps continuous shooting for 20 frames in S mode. No hotshoe and no lens threads. Use AA battery power. The difference among them is only the zoom capabilities. S4000 30x (24-720mm), S3400 28x (24-672mm), S3300 26x (24-624mm), S3200 24x (24-576mm)[32][33][34]
The other rival has some lacks or inferiorities: Olympus SP-800UZ: 14.0 MP CCD sensor, 30x optical zoom (28-840mm) plus digital zoom 5x, internal memory 2 GB, 10 frame/s burst mode, but only HD 1280*720 at 30 frame/s with no sound, No external hot shoe, No aperture priority, No shutter priority, No lens thread, No view finder.[35][36]
A few bridgecams, known as Hybrid Cameras, have features similar to those of a DSLR (PSAM mode, (external) hot shoe, EVF and RAW record) and advanced video features including Full HD Stereo Video (1920 x 1080 format at 30 frame/s) and a 'quiet' ultrasonic motor able to operate the optical zoom and autofocus while filming. These include the Canon PowerShot SX1 IS [37]
The market for bridge cameras is gradually being squeezed from both ends of the range. Inexpensive DSLRs often overlap with bridge cameras, and manufacturers give priority to DSLRs since they can enjoy further profits from the sale of aftermarket lenses and accessories. Compact cameras are also released with advanced functionality and large zoom ranges, features that could previously only be found in bridge cameras.[38] However, compacts generally rely on automation and the menu system, lacking the multiple dials, rings, pushbuttons or other direct controls that allow efficient manual operations for users who study their bridge camera. Third-party manuals are available for particular popular models, as they are for DSLRs, but they are scarce for classic compacts.
A recent category is the mirrorless interchangeable lens camera, which features a large sensor and an interchangeable lens, but no mirror. These occupy a niche at the top end of the bridge camera range, and in many respects (such as live view or electronic viewfinder only) are similar to smaller ones. They differ in that the larger sensor provides advantages (as noted above), but makes super-zoom lenses more difficult, hence the interchangeable lens.