QSI 500 Series cameras are optimized to provide the lowest
noise and highest possible Signal-to-Noise Ratio (SNR) for low light applications. One key aspect to meet that design criteria is a relatively slow read
rate of approximately 500,000 pixels per second.
QSI 600 Series cameras offer dual read rates and High Speed USB 2.0, supporting much faster downloads. The cameras have a High Quality mode, similar to the 500 Series but about 50% faster (800,000 pixels per second), offering the lowest read noise and widest possible dynamic range, and a High Speed mode of 8 MHz for focusing, framing, and for applications that require higher frame rates. See below for 600 Series read times.
Download times with both 500 and 600 Series cameras will be reduced by binning or reading just a subframe (ROI) from the sensor.
QSI 500 Series Image Read Times
|Camera Model||Download Time (sec)|
|QSI 504||1 sec.|
|QSI 516||4 sec.|
|QSI 532||8 sec.|
|QSI 520||5 sec.|
|QSI 540||11 sec.|
|QSI 583||21 sec.|
QSI 600 Series Image Read Times
|Camera Model||High Quality Mode(sec)||High Speed Mode (sec)|
|QSI 604||<1 sec.||0.1 sec.|
|QSI 616||3 sec.||0.3 sec.|
|QSI 632||5 sec.||0.5 sec.|
|QSI 620||3 sec.||0.3 sec.|
|QSI 640||7 sec.||<1 sec.|
|QSI 683||13 sec.||< 2 sec.|
Download speed is not the only factor that affects how quickly you can capture an image with the quality (SNR) you require. The read noise in QSI cameras displays a nearly
perfect Gaussian distribution with no fixed pattern noise as revealed by FFT
analysis done on every camera. This allows you to achieve the highest
possible Signal-to-Noise Ratio in your individual sub-frames and final
images. See “Understanding CCD Noise” for a more complete discussion of the sources of noise in CCD images.