Manual Focusing Tool¶

The Manual Focus window opens when you click on the tool or when you add it in the focus sequence and the focuser goes through that after receiving a focus target.

1. click "Set Instrument" to send what Leginon thinks is zero defocus to the microscope.

2. If the above does not take you to zero defocus judged by the Thon rings of the CTF in the power spectrum shown, move the defocus up or down relatively be fixed increment by clicking "+" or "-" buttons in the tool bar. The Thon rings of the CTF in the FFT should disappear once the defocus is at Gaussion focus relative to the specimen (often called zero defocus). Repeat this step and adjust the direction and increment until defocus is at Gaussian focus.

• The increment can be set by left-click at the first ctf node of the power spectrum.*

3. Clicking the Stop button exits the manual check.