Using ScanImage 3.x, I notice a 'mirror image' on either the left or right side of the image. What's going on?
The 'mirror image' can appear when using sawtooth scanning (not bidirectional scanning). You are observing the fast mirror flyback. This occurs when the fill fraction is too high for a given line rate (the ms per line value) and zoom factor.
The general procedure to optimize your scan parameters is as follows:
- Switch to bidirectional scanning and then adjust the acquisition delay so that every other line appears aligned in the image
- Adjust the scan delay to as nearly 2x the acquisition delay as possible (the scan delay is adjustable in fairly coarse increments)
- Reduce the fill fraction until the mirror image just disappears or is barely visible at the right edge of the image
The optimal fill fraction can vary with the zoom level, so you may need to specify separate values for different zoom levels, which can be done in the Configuration panel.
For more information, see Fast (X) Scan Dimension Optimization.