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©2016 QImaging. All rights reserved. QI_Retiga R Series Camera_UM_Rev_A5
10
RETIGA R
™
SERIES USER MANUAL
Gain State 1 leverages the larger charge capacity of the serial register, in order to extend dynamic range. This
advantage can only take place when binning. Gain State 2 utilizes the full dynamic range of the pixel and is
recommended for applications requiring moderate sensitivity. Gain State 3, 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 QI Retiga R Series camera system provides regulated sensor
cooling of at least -12ºC 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.
