Select Focus Mode (no sweep) and acquire an image. This removes any fast timing issues. Also turn the gated cathode to Normally ON. In more detail:
- From the CCD tab, go to the System Mode dropdown and select “Focus”.
- Set CCD Mode to “Fast Focus Mode”.
- Change the trigger (SRS box) from single shot to 0.5 Hz.
- Acquire a background image (CCD → Acquire to B).
- Select CCD → Acquire Continuously, Forever, 0 seconds.
- Input optics can now be aligned, with visual feedback at 0.5 Hz.
Select Sync Mode.
- Does the signal “pile up” at the starting point? If so, the ramps are firing too late relative to the signal.
- Does signal appear to the right of starting point, or no signal at all? If so, the ramps are firing too early relative to source.