CHAPTER 1 - SYSTEM OPERATIONLSM 880 Left Tool Area and Hardware Control Tools ZEISS10/2014 V_01 000000-2071-464 1275.2.11 Acquisition Parameter – FocusDevices and StrategyFocus Devices and Strategy aims to maintainfocus stability in multi-dimensional acquisitionexperiments.This tool is typically employed to compensate for Z-drift in time series experiments as well as for thetilt of samples when recording at multiple positionsusing a scanning stage.Focus Devices and Strategy features fourdifferent autofocus modes to be used incombination with the acquisition tools TimeSeries, Tile Scan and Positions.These modes employ either the optional module Definite Focus or the built-in detection capabilities ofthe LSM.The set of available autofocus modes therefore depends upon a system's hardware configuration. TheLSM-based autofocus modes Fluorescence, Reflection and Autofocus Map cannot be used if anacquisition strategy includes tracks with camera-based image recording.The Focus Devices and Strategy tool (Fig. 169) provides controls for maintaining focus stability with theTile Scan and Positions tools.Autofocus Mode specifies the method to be used throughout the course of amulti-dimensional experiment.The menu for mode selection features a maximum of four active modes(or Off mode):− Fluorescence− Reflection− Autofocus Map− Definite FocusAll LSM-based autofocus modes rely on the optical sectioning capabilities of a LSM for precisely locatingsignal intensity maxima in the Z-direction.The Z-position of an intensity maximum found within the search range is used as a reference for thepositioning of the imaging plane in the Z-direction.In many cases, reference and imaging plane are not identical but differ by a fixed distance referred to asoffset (see Reflection and Autofocus Map modes below).Whenever a focusing action is executed, the Z-position of the imaging plane is updated.Fig. 169 Focus Devices and Strategy tool
