Zeiss LSM 880, Operating Manual

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CHAPTER 1 - SYSTEM OPERATION
LSM 880 Left Tool Area and Hardware Control Tools ZEISS
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5.2.9.3 Using GaAsP Detectors and the
temperature controlled side PMT for
Photon Counting Imaging
In the LSM Imaging Setup tool activate any GaAsP
detector like BiG.2, the 32 channel GaAsP Array
detector or the temperature controlled side PMT
(Ch2).
Select
Photon Counting for the detector in the
Channels Too
l (Fig. 159).
In photon counting imaging a Digital Offset and
Digital Gain slider is available, which can be used to
adjust brightness and contrast of the image during
scanning.
In photon counting mode an artificial maximum of
detectable photons is set. For all GaAsP detectors and
the side PMT (CH2) this value is defined by
CR
max
/digital gain (CR
max
= maximal count rate defined
by the software, which is 4 MHz for the BiG.2 and
Ch2 and 2 MHz for CHs (32 channel GaAsP Array).
Higher count rates are regarded as saturation. Note
that too much light on the detectors (higher count
rates for some ms) leads to detector shut down to
avoid damage.
(1) Display of Photon Count Images
There are two ways photon counting images can
be displayed in the LSM software, in analog (grey
value) or counting (raw data) mode.
You can toggle between the two modes in the
Maintain
area
Options / System Options
in the
Hardware
tab by deactivating or activating the
Keep raw data for photon count detectors
check box (Fig. 160).
If the box is checked, you will obtain the photon
counts, if unchecked, grey values corresponding to
photon counts.
Fig. 159 Channels tool – Photon counting
mode for GaAsP detector
Fig. 160 Hardware tab in the Systems
Options tool/Maintain tab