Focus Window
The Focus Window is the primary window that allows you to select the method for autofocus and monitor the auto focus operation with a display of the target star Half Flux Diameter (HFD).
The blue lines beneath the Camera, Focuser and Telescope indicate that the respective hardware is connected.
The black line beneath the telescope menu indicates that the telescope is tracking
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System buttons
The colored buttons in the upper left are used to manually toggle between the two configured systems.
If only one system is configured then the second system button will not be enabled.
Pressing the Find button will:
Expose a frame using using the Target Star binning in Preferences
Find the brightest star
Subframe the star using the focus binning defined on Preferences
Adjust the stating base exposure up or down to meet the Target Flux setting in Preferences
Takes a single exposure subframe image using the focus binning defined in Preferences.
This button is normally used following Find (star) operation.
Initiates the auto focus operation centered on the brightest star or selected star on the chip
Take a binned image as defined in Preferences / Setup
Automatically find the brightest star
Measure the HFD (Half Flux Diameter) and calculate total star flux
Subframe the star using the focus binning (Preferences)
Adjust the exposure up or down starting at the base exposure (Preferences) to bring the star flux is close to the Target Flux value (Preferences)
Make a few moves to verify that the focuser on the correct side of the Vcurve
Move the focuser to the Near Focus HFD setting (Preferences)
Take multiple images and measure the target star HFD
Calculate the focus position
Move the focuser to the focus position
Verify that focus quality
The details of the auto focus algorithm is further explained FocusMax Menu/Help/Technical Paper.
Pressing Select allows the user to select a specific star in the field for auto focus (MaxIm only) which is useful in crowded star fields or if you do not want to leave the current field.
Initiate taking a full frame image
You to click on a target star
FocusMax initiates the autofocus routine.
Selects a star from a star catalog, slews the telescope, performs the autofocus routine then performs a return slew. This requires TheSkyX Image Link with camera-add-on or the full version of PinPoint to be installed.
See AcquireStar for more.
Can be clicked at any time during an active operation to terminate an operation.
The focuser position is displayed near the top of the Focus Tab Window along with the temperature if the focuser has temperature-sensing capability.
If you are using a relative focuser then double clicking the Position window will zero the Position value.
The large graphical box is a vertical bin of the framed region centered on the star. The vertical lines to the left and right of the curve is the boundaries of the star. The regions outside of the boundaries are used to determine the background level of the image, which is subtracted from the image before the vertical bin curve is plotted.
The left small box near the bottom shows the position of the selected star on the camera chip. The smaller box inside shows the Central Region defined by the Features Tab, "CCD Central Region" when enabled and Percent of the chip specified to look for the star to be used.
The right small box shows a plot of the star diameter along the x-axis and integrated flux along the y-axis. The integrated flux is zero at the edge of the star and increases to the full star flux at the star diameter. The Half Diameter (HFD) is the point marked on the flux integral plot with a vertical line.
