Leginon

h1. Camera length calibration

Camera length calibration can be simply done by acquiring a diffraction image of cross-grating replica and enter the expected d-spacing of Au-Pd power rings and measure the diameter of the ring in Leginon gui.

It will also save a pixel size equivalent that allows the webviewer to display the diffraction image and use its ruler to estimate the resolution.

* This is only tested on TFS Ceta and Tvips F416 at 2kx2k bin 2

# Send a diffraction tem preset.  See [[Setup df preset]]

# Select "Camera Length" node

# Click "Acquire Image"

# Measure the diameter of the ring in pixels.

# Click "Ruler" tool to enter the expected d-spacing and measurement, and then click "Calculate"

# Multiple measurements can be made with the same preset and the camera length averaged.

# Select the camera lengths to be averaged and saved, and save them.

Direct Edit and Extrapolation is possible just like in [[Pixel Size Calibration|Pixel Size Calibrator]].