Teledyne Photometrics Everywhereyoulook KINETIX, Manual, Page: 22 / 41

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The lack of a charge transfer process in CMOS devices means true charge binning is not
available in currently available sCMOS sensors. Even so, co-adding pixels is a convenient
means to reduce image data, or increase signal by 4x and improve SNR by 2x as the noise
from each pixel adds in quadrature.
Kinetix includes 2x2 on-camera simulated binning, done on the FPGA. This mathematically
combines signal from adjacent pixels and adjusts the sum so that the bias offset is only
added one time.
Sensor Clearing
In order to capture the highest signal to noise ratio possible, it is important that scientific
cameras minimize any signal that’s not derived from the sample. One contribution to this
background signal is the buildup of charge prior to an exposure, which includes any light still
reaching the sensor and thermally generated sensor dark current. To eliminate this pre-
acquisition charge accumulation, most CCD and CMOS cameras clear the sensor one or more
times prior to exposing the sensor to light. This can be done using a “fast” readout that is
subsequently discarded.
Unlike CCDs, there is limited benefit to performing multiple pre-exposure clearing cycles
with CMOS, because each pixel is reset as part of the normal readout process, and the
charge transfer registers that can hold residual signals are not present.
Bias Offset
Scientific cameras produce a fixed artificial signal offset known as bias offset. This offset is
present even when no light is falling on the sensor and the exposure time is set to zero. This
preserves quantitation even down to signals of a few electrons per pixel. Typically, the user
subtracts this offset before performing quantitative analysis post-acquisition.
The recommended protocol is to capture a new series of bias frames at the start of each
experimental run. The series of frames can be averaged to remove noise, then used to
remove the bias offset during subsequent image analysis. This can also be used to monitor
for light leaks and other systematic effects that can impact experimental results.
Pixel Noise
Filters
Note: The Kinetix camera ships with an optimized default setting for Real Time Pixel
Noise Filtering. Normally these values do not need to be adjusted. Additionally, the
features described in this section may not be controllable in the software application. This
is an advanced usage section.