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If the peak maximum remains low even at maximum laser power, it may still be useable if it is
still significantly above any background signal. Proceed to step 6.3.4. Note however that higher
magnification objectives than the one currently in use may not allow enough laser signal to
operate the PureFocus850. If low peak maxima are already apparent at 5-20x magnification,
or no peak can be identified, refer to Section 10: Troubleshooting.
6.3.4 Checking error swing
Error swing is essential for operation of the PureFocus850. The speed and magnitude of swing
contribute to the focus recovery range and focus stability. Error swing is indicated by the green
bars in the centre of the main interface of the PureFocus850 GUI.
Set the PureFocus controller into MAN FOC mode.
Rotate the digipot clockwise to bring the sample out of focus. The error bar will swing towards
+1 or -1, with the error signal value indicated to the right. Make a note of the maximum error
value. Rotate the signal anticlockwise, passing through focus and putting the sample out of
