scanner camera

A scanner camera is a digital camera with a line sensor. There are two basic types; a combination of an analog camera with a digital camera back ( called ScanBack ) or as a unit.

From the scanning principle, the limited field of application in the professional photography for repro photography and still life derives. Chance you will also find applications in landscape photography and scientific photography. The long exposure time results from the sequential exposure of each line of the image.

Operation

Scanning cameras operate on the scanner principle, that is, they work much like a flatbed scanner. The image is scanned line by line, while the line sensor is performed mechanically by means of a stepping motor of the image area.

Scanning cameras work very slowly, the scan of an image takes about twelve minutes; in addition, no flash can be used. The opportunity to photograph moving motifs is dependent on their speed, scan moving subjects, is only possible with the loss of sharpness, similar to the procedures used a long exposure. The subject is moving much faster out of the picture, as the exposure lasts, it can be seen which may be only an outline or anything.

A further development that was launched in 2007 by Seitz in collaboration with the sensor manufacturer DALSA to market, allows shorter exposure times (from about one second ). This also images of moving scenes are possible. The underlying principle is the use of multiple, adjacent superimposed scanning lines on a chip. While the sensor mechanically leaves the image are synchronized electronically shifted the image of the contents of a scan line to the next, so that a total of more senses light and the exposure time can be shortened.

Use and characteristics

Scanner cameras, as well as three-shot cameras used with image sensor as the high-quality studio cameras. Thus scanner cameras produce very large files due to the high resolution and image area. The cameras need flicker continuous light and can be used only for immovable designs. They are also increasingly dependent on direct connection to a computer and only limited use in the field ( needed is a battery power supply for laptop and ScanBack control).

In times of ever- higher -resolution image sensors, the importance of scanbacks in normal studio operation is greatly decreasing. There are only a few manufacturers, such as:

• Fa anagram ( picture gate 8000 david ²) with uninterpolierten 16,000 × 26,000 pixels screen resolution and 48 bit color depth,
• Fa Better Light ( S10K -HS ) with 10,200 -element Kodak line and a resolution of 10,200 × 13,800 pixels
• Fa Pentacon (Scan 7000) with 20,000 × 20,000 pixels at 48-bit color with SilverFast Archive Suite (novelty at the photokina 2010).

These resolutions are far above those available image sensors and even the number of sensors of the human eye. In the area of ​​reproduction of art and scientific photography (example: digital herbarium ), there is therefore no alternative to Scannerkammera.

Also interesting is the fact that, often makes the use is inevitable in other areas, where it depends on accurate color reproduction at high resolution: Since scanning cameras all colors ( RGB 3-line scanner) to "see" and not like cameras with One -shot sensor and Bayer mosaic color filter with the interpolating a large portion of blue and red ( on a "one shot " image sensor are 50 % green-sensitive, 25 % red-sensitive and 25 % blue-sensitive pixels) must be satisfied, the data quality is to multiples than is the case at higher its not scanned competition.

There are also panoramic cameras, for example, for the FBI for crime scene photography ( CSU ) and the military in topographic surveys for high-resolution combat simulators.