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10
RETIGA ELECTRO
™
USER MANUAL
Gain State 1 uses the full dynamic range of the pixel and is recommended for applications requiring moderate
sensitivity. Gain State 2, although only using a half of the single pixel full well, is ideal for resolving low
luminescence signals due to the very lowest read noise attainable.
Sensor Cooling
To further reduce thermally generated noise, the Retiga ELECTRO camera system provides regulated sensor
cooling of 0ºC in a 22°C ambient, which effectively eliminates dark current noise from typical imaging
scenarios.
Clearing Mode
When the camera does not expose and read out images simultaneously, it is in Non-Overlap Mode. Non-
Overlap Mode is set by choosing “Pre-Exposure Clearing” for the clearing mode of the camera. This allows the
sensor to clear accumulated charge before the start of each exposure.
The following waveforms show how Non-Overlap Mode functions. The main benefit of Non-Overlap Mode is
that there are no limitations imposed upon the exposure time, and the set exposure time is the actual exposure
time. The tradeoff for this accuracy is the frame rate, as each frame must be completely digitized before
beginning the next exposure cycle.
When the camera is able to expose and read out images simultaneously, it is in Overlap Mode. Overlap Mode is
set by choosing “Pre-Sequence Clearing” for the clearing mode of the camera. This allows one clear before the
imaging sequence starts. The following waveforms show how Overlap Mode functions. When using Overlap
Mode, the frame rate is higher as compared to Non-Overlap Mode and provides the ability to continuously
image. However, since exposure and readout occur simultaneously, the minimum exposure time is dependent
on the time taken to complete readout. In timed mode + Overlap Mode, exposure times may be set that are
shorter than the readout time, as shown in timing diagram below.