Gatan UltraScan 894, Руководство пользователя

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UltraScan Use r ’s Guide Reference Series Rev 1.0 3-1
3 Image Acquisition
This chapter contains some instructions on how to acquire an image and a
description of the most frequently used floating windows.
Now you are ready to:
•
Insert the sample,
•
Find a region of interest
•
Start using the CCD camera to view your specimen.
3.1 View
The view mode (shown in Figure 3-1) allows user to observe Live (continuous)
images on the monitor. The setup has two operation modes which are preset for
easy use:
•
The Search mode displays a continuous (low resolution) image with
the entire CCD field of view. This is to allow the user to quickly
conduct a sample search using the CCD camera.
•
The Focus mode displays a continuous image at higher resolution than
the Search image. Fine adjustment of focus setting can be done with
this operation mode.
In addition, there is another way to adjust the image focus. Click on the Focus
Loupe . This allows the user to focus the image by using a small image area
with high speed. The size of the box can be resized by dragging its corner and
its location can be easily changed by putting the pointer inside the box and
dragging it. The
Auto Survey option adjusts the brightness and the contrast in
real time for optimal image quality.
Auto Exposure is enabled and disabled by clicking on the Auto Exposure
selection box. Since a test exposure must be made regularly to ensure proper
exposure time for the beam intensity on the CCD and for 4kx4k CCD, this
means 16million pixels must be read out each time, it is recommended to turn