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Furthermore, LightScan PLUS offers the user multiple new scanning directions for the rolling shutter
mechanism in which both sides of the sensor can be used simultaneously, synchronized to two scanning
lasers, thus providing the option to utilize the full ‘Dual Port Readout’ capability of the sensor and provide
100 fps full resolution frame rate. These new scanning options for sCMOS are also ideal for dual-wavelength
applications where two light sources are scanning across the image sensor with different wavelengths. The
multi-laser readout configurations are illustrated below in Figure 35.
Figure 35: Multiple ‘dual laser’ scanning options available. The standard rolling shutter scan mode (Centre outwards in both
directionssimultaneously) is illustrated on the left along with the three additional scanning options.
For each of the various scanning options outlined above, CycleMax - a feature of LightScan PLUS – ensures
minimum dead time between scans by enabling the laser sweep and corresponding rolling shutter scan
direction to alternate from top-bottom to bottom-top, therefore avoiding the need to reset the laser for each
subsequent image. Furthermore, a programmable trigger delay has been built into LightScan Plus enabling
the user to input a defined delay time between the camera receiving an external trigger and the acquisition
start. This is important when using peripheral devices e.g. controlling the illumination source.
2.7.7.2 FlexiScan
Flexiscan functionality allows the user to optimize between the conflicting parameters of confocality
(Exposure Window Height), frame rate (Line Scan Speed dependent) and exposure. A logical way to think
about this is; set the Exposure Window Height to achieve the degree of confocality (fewer rows gives more
background haze removal), next set the Line Scan Speed to achieve an exposure time that allows you to get
a good enough signal strength to see what you intend to measure, and finally synchronize the optical scanner
speed to this resultant readout.
Table 33 denotes the scan speed range flexibility of LightScan PLUS in terms of scan speed.
Table 33: Global Range of Line Scan Speeds available through FlexiScan for each pixel readout rate. Also
shown is the resultant range of scan times for one full image (full top to bottom or bottom to top sweep)
and the resultant exposure range, assuming a ‘slit width’ of 10 rows.
Parameter
*216 MHz
*540 MHz
Line scan speed range (rows/ms)
2.98 - 41.67
7.43 - 104
Resultant scan time for one
full image (ms)
49 - 686
19.69 - 275.66
Resultant exposure range
for slit width of 10 rows (ms)
0.240 - 3.36
0.096 - 1.344
Users are advised not to input a value for line scan speed referring to a pre-selected scanning speed of the
illumination light, but to adjust the scanning speed of the illumination for the synchronization instead.
Summary of Contents for Zyla sCMOS 4.2 PLUS
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