Low pass filters are placed directly in front of sensors to reduce the incidence of interference or moire effects. They also act as a useful protection for the sensor surface, and on some cameras the low pass filter can be [...]
Tag Archive for 'Sensors'
The sensors in digital SLRs do sometimes need cleaning. The usual problem is dust spots, and although many cameras now have dust removal systems which briefly vibrate the sensor (or a filter in front) to dislodge any dust, these are [...]
The sensor in a digital camera is equivalent to the film in a traditional camera. Where the film is processed at a lab to produce the image, digital cameras process the image data produced by the sensor and save the [...]
Number of pixels on a sensor or pixels per inch in prints. A term which can mean different things in different contexts. In a digital camera, it’s the number of pixels (or ‘megapixels’) in the sensor. When you’re editing an [...]
Basic building block of digital photos. Every digital photo is made up of pixels, and each pixel is a square block of a single colour. Viewed from far enough away, the pixels and the colours merge to produce the impression [...]
Photosites are the tiny light receptors on a camera sensor. A single sensor contains millions of photosites, or ‘pixels’ – hence the term ‘mega’ (millions) pixels. The light value measured by each photosite is then converted into a digital value and [...]
This is a unique three-layer sensor design used by Sigma in its SD14 digital SLR and DP1 and DP2 compacts. The Foveon sensor doesn’t organise red, green and blue pixels in a mosaic on a single layer. Instead, it copies [...]
Dynamic range is a camera’s ability to record extremes of light and dark. It didn’t concern film photographers much because film generally has a high dynamic range, but digital sensors are different. Too much light will ‘overload’ the photosites so [...]
Digital camera sensors use grids of red, green and blue pixels. Each pixel can only record red, green or blue light. Each pixel produces a single block of colour and, as a result, the image at this point looks like [...]
CCD stands for Charge Coupled Device, and it’s one of two common types of sensor used used in digital cameras. It’s usually found in compact cameras and some basic D-SLRs. At one time, CCDs were considered the best and most expensive [...]
The ‘bayer’ pattern has become a standard way of arranging the photosites on conventional camera sensor. The photosites (pixels) are sensitive only to light, not colour, so miniature red, green and blue filters are placed over each photosite, and this [...]