A digital camera is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor.
Many compact digital still cameras can record sound and moving video as well as still photographs. Most 21st century cameras are digital.
There are five different types of digital camera -
- Compact Digital Camera
- Bridge Cameras
- Mirrorless Interchangeable Lens Camera
- Digital Single Lens Reflex Cameras
- Digital Rangefinders
Compact cameras are designed to be tiny and portable and are particularly suitable for casual and "snapshot" use. The smallest, generally less than 20 mm thick, are described as subcompacts or "ultra-compacts".Most, apart from ruggedized or water-resistant models, incorporate a retractable lens assembly allowing a thin camera to have a moderately long focal length and thus fully exploit an image sensor larger than that on a camera phone, and a mechanized lens cap to cover the lens when retracted. The retracted and capped lens is protected from keys, coins and other hard objects, thus making a thin, pocketable package.
Compact cameras are usually designed to be easy to use, sacrificing advanced features and picture quality for compactness and simplicity; images can usually only be stored using lossy compression (JPEG). Most have a built-in flash usually of low power, sufficient for nearby subjects. For lower cost and smaller size, these cameras typically use image sensors with a diagonal of approximately 6 mm. This gives them weaker low-light performance, greater depth of field, generally closer focusing ability, and smaller components than cameras using larger sensors.
An example of a compact digital camera is the Nikon L21 which can be purchased for £55.99
http://www.amazon.co.uk/Nikon-L21-Digital-Camera-Optical/dp/B0036WN358/ref=sr_1_19?s=electronics&ie=UTF8&qid=1288637214&sr=1-19
Bridge cameras are cameras which fill the niche between the SLRs and the Compact cameras.They are often comparable in size and weight to the smallest Digital SLR's (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. The term "Bridge camera" was originally used to refer to film cameras which "bridged the gap" between point and shoot cameras and SLRs.
An example of a bridge camera is the new Nikon P100 which can be purchased for £269.00
http://www.amazon.co.uk/Nikon-P100-Digital-Camera-Optical/dp/B0036WN2F4/ref=dp_ob_title_ce
The purpose of Mirrorless Interchangeable Lens Cameras is to provide high quality imaging in a smaller body than in DSLR cameras. Prior to the introduction of Micros, digital cameras featured either a small sensor (in various body styles), or a large sensor in a DSLR body, with very rare exception and one was faced with a sharp trade-off between small-but-poor-quality or high-quality-but-large. DSLR cameras provide high quality imaging, but use essentially the same design and lenses as existing film SLR cameras; micros by contrast represent a break from the legacy of cameras designed for film.
A digital display screen on the camera serves the dual purpose of an electronic viewfinder and status display for setting camera functions. Short of these mechanisms, micros can have significantly thinner and lighter bodies with fewer moving parts. Further, by placing the lens closer to the sensor, smaller (and accordingly cheaper and lighter) lenses can be used, which is particularly significant for wide-angle lenses. Thus, due to the absence of a light box and having smaller lenses, micros are significantly smaller and lighter than DSLRs.
An example of a Mirrorless Interchangeable Lens Camera is the Samsung NX100 which can be purchased for £429.00
http://www.amazon.co.uk/Samsung-NX100-Interchangeable-Lens-Camera/dp/B00472MGPE/ref=sr_1_1?ie=UTF8&qid=1288637516&sr=1-1
A digital single-lens reflex camera is a digital camera that uses a mechanical mirror system and pentaprismlens to an optical viewfinder on the back of the camera. The basic operation of a DSLR is as follows: for viewing purposes, the mirror reflects the light coming through the attached lens upwards at a 90 degree angle. It is then reflected three times by the roof pentaprism, rectifying it for the photographer's eye. (Note that the diagram below incorrectly shows a non-roof pentaprism.) During exposure, the mirror assembly swings upward, the aperture narrows (if stopped down, or set smaller than wide open), and a shutter opens, allowing the lens to project light onto the image sensor. A second shutter then covers the sensor, ending the exposure, and the mirror lowers while the shutter resets. The period that the mirror is flipped up is referred to as "viewfinder blackout". A fast-acting mirror and shutter is preferred so as to not delay an action photo. All of this happens automatically over a period of milliseconds, with cameras designed to do this 3–10 times per second.DSLRs are often preferred by professional still photographers because they allow an accurate preview of framing close to the moment of exposure, and because DSLRs allow the user to choose from a variety of interchangeable lenses.
An example of a DSLR is the Nikon D7000 which is due to be released shortly for the price of £1029.00
http://www.amazon.co.uk/Nikon-VBA290AB-D7000-Body-Only/dp/B00437RK7C/ref=sr_1_6?s=electronics&ie=UTF8&qid=1288638227&sr=1-6
A rangefinder camera is a camera fitted with a rangefinder: a range-finding focusing mechanism allowing the photographer to measure the subject distance and take photographs that are in sharp focus. Most varieties of rangefinder show two images of the same subject, one of which moves when a calibrated wheel is turned; when the two images coincide and fuse into one, the distance can be read off the wheel. Older, non-coupled rangefinder cameras display the focusing distance and require the photographer to transfer the value to the lens focus ring; cameras without built-in rangefinders could have an external rangefinder fitted into the accessory shoe. Earlier cameras of this type had separate viewfinder and rangefinder windows; later the rangefinder was incorporated into the viewfinder. More modern designs have rangefinders coupled to the focusing mechanism, so that the lens is focused correctly when the rangefinder images fuse; compare with the focusing screen in non-autofocus SLRs.
An example of a rangefinder camera is the Leica M8.2 which can still be purchased for £3914.99
http://www.jacobsdigital.co.uk/p-36859-jacobs-digital-leica-m82-black.aspx
No comments:
Post a Comment