Super CCD sensor
The Super-CCD-Sensor ( SCCD ) is a light-sensitive chip for digital cameras . It is a constant further development of the CCD sensor from Fujifilm since 2000, which is characterized by a honeycomb arrangement of the sensor cells (rotation of the cells by 45 degrees). SCCD sensors can be divided into the types HR and SR, whereby SCCD SR has a higher dynamic range.
Fujifilm used super CCD sensors in its upscale digital camera models for years. In the course of the 2010s, the manufacturer switched to CMOS sensors, the cell arrangement of which is also modified compared to the standard (see for example Fujifilm-X-Trans-Sensor ).
Sensor technology
The chosen 45-degree arrangement leads to a smaller distance between the sensor elements in the horizontal and vertical direction. Due to the octagonal shape of the pixels, the light-sensitive surface was enlarged. This results in both a significantly higher sensitivity to light and an improved image quality of picture elements that are placed horizontally or vertically in the picture motif.
The image signals of the Super-CCD sensor are converted back into the rectangular format of the image file by interpolation, whereby depending on the variant of the sensor, 30 to 50 percent more pixels result than would correspond to the physical resolution of the Super-CCD. In addition, a particularly high light sensitivity is achieved without the image noise deteriorating as much at higher sensitivities as with conventional CCD sensors.
Furthermore, microlenses are used on numerous variants of this sensor category , which also increases the light yield and reduces noise.
Dynamic expansion
Newer SCCD sensors (called SCCD SR ) have a light-sensitive element with high sensitivity (large light-sensitive area, S-pixel) and a less sensitive element (small area, R-pixel) that can process higher light intensities for each pixel. This records a second, underexposed image when taking the picture, which is offset against the first. This extends the dynamic range (exposure latitude).
Fuji has been manufacturing the SuperCCD-EXR sensor since 2008, which, thanks to a different arrangement of the Bayer matrix (color filter), enables the optional interconnection of neighboring "same-colored" sensor pixels and thus, depending on the control, reduces the image noise, optimizes the resolution or the usable dynamic range can expand.
Color version
With the SCCD sensor, as with most digital cameras, the color information is captured by color filters based on the Bayer matrix principle , but the arrangement of the color filters is partially modified compared to the conventional Bayer matrix.
Resolution rating
The mode of operation gives rise to difficulties in comparing the effective resolution with CCD or CMOS cameras; For example, Fuji specifies a sensor resolution of 2.4 megapixels and an image resolution of 4.3 megapixels for the FinePix 4700 Zoom . The practical value of increasing the resolution is therefore controversial; Experience has shown that you can expect an image quality that is in the range of conventional cameras between the actual and interpolated resolution, in the case of the Finepix 4700 Zoom that is about the level of a 3 megapixel camera.
Photosensitivity
The development of the sensor is mainly focused on higher light sensitivity. Cameras of the Finepix series should be able to deliver images with lower noise than conventional CCD chips of the same size even with very high exposure indices (as of January 2007: ISO 3200). But they cannot match the performance of larger CMOS sensors in the current, much more expensive SLR and system cameras.
See also
Web links
- Fuji Super-CCD Detailed, illustrated description of the concept and further development of SCCD
- Report on Super-CCDs detailed operation of the Super-CCD SR sensors
Individual evidence
- ↑ First with superchip . test.de ; Retrieved October 1, 2012