User manual

Rolera Thunder User Manual 16
Conversion Gain
Apart from multiplication gain, which actually multiplies the number of electrons generated in
each pixel, the Rolera Thunder also has three (3) conversion gains. Conversion gain simply
quantifies how the resulting electrons are converted into ADU (Analog-to-Digital units) and
displayed on the display screen.
Typical conversion gains for the readout port are listed later in this chapter. Your camera is
individually calibrated for these gains. So, please refer to the certificate of performance that
accompanied your camera.
Note: As the on-chip multiplication introduces additional noise, it is recommended that the multiplication
be used only as required. For more information, refer to the "On-Chip Multiplication Gain" technical note.
This technical note can be accessed by going to the QImaging web site at www. qimaging.com, clicking on
"Library", clicking on "Technical Notes", and selecting the title from the list of notes.
Readout Speed
(Typical)
Rolera Thunder cameras are implemented with 10 MHz, 5MHz and 1.25 MHz digitization speeds
(10 million, 5 million and 1.25 million pixels per second, respectively). At 10 MHz it gives
approximately 31 frames per second (fps), whereas 1.25 MHz operation offers better image
quality. With either digitizer, increased frame rate can be achieved by choosing a sub-region. For
more information, please refer to the product data sheets.
The camera uses a frame-transfer CCD with a built-in storage (frame transfer) area, which makes
simultaneous exposure and readout possible (Overlap mode) and which allows precise exposures
to be set (Non-Overlap mode). These two readout modes are further explained in the "Exposure
- Readout Modes" section in this chapter.
Binning
Binning (combining pixels into one super pixel) allows you to increase the sensitivity and frame
rate. On the other hand, binning reduces spatial resolution. The Rolera Thunder allows binning of
1, 2, 4, and 8 in the serial (horizontal) direction and 1 to 256 binning in the parallel direction.