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CHAPTER 4
ADVANCED CAMERA CONTROLS
The Intensified Retiga Fast 1394 employs several imaging elements to achieve high dynamic range,
high sensitivity imaging with fast gating capabilities. The camera’s electronics can control these
elements in concert making it easy for the user to acquire images. Some applications demand
sophisticated control over the imaging elements. The Intensified Retiga Fast 1394 provides the user
with such control to capture images that are, for example, synchronized to fast external events or
optimized for an intensity range of interest. This section explains the operation and control of the
various imaging elements employed by the Intensified Retiga Fast 1394.
Integration Controls
The Intensified Retiga Fast 1394 has two shutter elements that control integration: The Image
Intensifier Tube Gate and the CCD Electronic Shutter. When acquiring images, the gate and CCD
shutter are controlled in concert. This is achieved either by the Intensified Retiga Fast 1394’s
electronics, or by specially timed electrical pulses provided to the camera by the user.
Image Intensifier Tube Gate
The gate control of the Intensified Retiga Fast 1394’s Image Intensifier tube effectively works as a very
fast and precisely controlled shutter element. Like a shutter, the tube only passes light when the gate
is open. By using the gate as a shutter, the camera can achieve very short exposure times. The gate
can be controlled either by the camera’s electronics or directly by the user through the gate input.
CCD Electronic Shutter
The Intensified Retiga Fast 1394’s CCD has an electronic shutter. This shutter is relatively slow in
comparison to the Image Intensifier tube’s gate. The CCD’s shutter can be controlled either by the
camera’s electronics or by the user through the External Trigger Port.
Integration Modes
The Intensified Retiga Fast 1394 has two integration modes: Synchronous and User Controlled.
Synchronous mode allows the user to control the Intensified Retiga Fast 1394 in the same way as any
other QImaging camera, where all the details of shuttering and gating are handled by the Intensified
Retiga Fast 1394’s electronics. User Controlled mode requires the user to provide shutter and gate
control signals to the camera. While this mode is more complicated, it provides the user with more
control over the camera’s integration, which is required in some applications.
The Integration Mode is implicitly selected by the Trigger Mode selected in software, Table 1 shows
which Integration Mode is used by each Trigger Mode.
Synchonous
In synchronous mode, the camera’s electronics control both the CCD’s electronic shutter and the
photmultiplier tube gate in concert. Images are exposed for the exposure time selected in
software. Figure 11 is a timing diagram of the camera’s operation in this mode.
Содержание Intensified Retiga Fast 1394
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