CMOS高速相机

CMOS高速相机

pco.dimax HD | high speed CMOS cameras

free of session referencing
With innovative use of on chip information, the pco.dimax offers an operation free from session referencing,which does not require any additional mechanical shutter for dark referencing. The pco.dimax incorporates an internal fully automatic referencing feature that does not require additional operator intervention. Therefore it is possible to change frame rates “on the fly” (during recording).

color image quality
The pco.dimax incorporates sophisticated techniques to achieve its high color image quality, proven and recommended by broadcast experts and camera men. This quality applies for high speed frame rates to shoot slow motion clips as well as for standard broadcast frame rates (such as 50 to 60 fps for HDTV 1080p).A combination of special optical filters and an optimized color-calibration achieves an excellent sRGB image quality. According to ISO Standard 17321 the pco.dimax reaches quality grades of 83 SMI(matching high end digital cameras with typical
75 to 90 SMI). This can be seen by the typical test image sample in the figure, which shows a demanding scene for a correct Bayer pattern color conversion.

A typical test image with color checker, MTF test charts and challenging structures obtained with a color pco.dimax.

CMOS高速相机

pco.dimax HD | high speed CMOS cameras

low light performance
The customized CMOS image sensor in combination with proprietary algorithms achieves a very low dark signal non-uniformity (DSNU), which can be seen in the figure in a comparison of the dark image of a standard high speed CMOS image sensor and a dark image of the pco.dimax. Hence high quality images can also be recorded at low light sceneries. The low light performance is even further improved by the CDI mode, which is explained in the next section.

The top image shows the typical fixed pattern structures in the dark image of high speed CMOS image sensors, while the lower image shows the lower and more homogeneous noise in the dark image of a pco.dimax.

CDI
If structural information in the dark side of the histogram of the images is of major importance, the pco.dimax with its correlated double image (CDI) mode offers to record images with increased dynamic range and a 30% better performance on the weak signal side of the images (at the expense of half of the usual frame rate).

A bald eagle catches its prey - original resolution 1920 x 1080 @ 500 frames/s (color version)

pco.dimax HD | high speed CMOS cameras

features

Crashtest, single extracted images of sequence - original resolution 2016 x 2016 @ 1102 frames/s (color version)

light sensitivity & ISO speed
Compared to analog photographic films, which are limited to one light sensitivity value, the pco.dimax offers a range of sensitivities (displayed as a band in the
figure) called ISO speeds, specified by the ISO Standard 12232. It defines the parameters ssat, snoise40 and snoise10 for digital camera characterization.Ssat gives the maximum amount of light the sensor can process. Snoise40 defines “excellent” and snoise10“acceptable image quality”. Both snoise40 and snoise10 are based on noise and quality image comparisons. Qualitatively speaking, the broader the band from ssat to snoise10 (see figure), the better the camera performance becomes. The pco.dimax provides image recording from ISO Speed 160, for highest quality, up to 16,000 and more at high frame rates.

linearity
For quantitative image measurements and analysis the linearity of the camera is a prerequisite. The EMVA 1288 linearity measurement results, as shown in the graph next to this text, demonstrate the scientific grade linearity that is a feature of the pco.dimax.

EMVA 1288 linearity measuements of a pco.dimax.

synchronization & trigger
A precise camera to camera synchronization for pco.dimax cameras is integrated by a master-slave mode with a remarkable low jitter (< 50 ns). Further a variety of trigger signals can be used for sequence as well as for single image triggering, allowing for low level, high level, differential and passive signals at the optically isolated inputs. Time code can be added by an IRIG-B signal (modulated or unmodulated). These features are extremely useful for stereo camera applications for 3D motion analysis and 3D particle image velocimetry (3D PIV) measurements.

pco.dimax HD | high speed CMOS cameras