# Calibration of a diffraction setup

Author: Jérôme Kieffer

Date: 20/01/2015

Keywords: Calibration

Target: Scientists

Associated video:
  http://www.edna-site.org/pub/calibration/calib.flv

## Review your calibration image

As viewer, try fabio_viewer from the FabIO package If you need to pre-process your data, look at pyFAI-average. In this example we have used a “max filter” over 20 frames using pyFAI-average.

## Get all additional data

> - calibrant used, here LaB6
> - the energy or the wavelength
> - detector geometry
> - masks, ...

## Start pyFAI-calib

Use the man page (or –help) to see all options

## Pick peaks

> - A few (5) points in the most inner
> - Increase the counter to indicate the ring number
> - Pick some extra point in outer ring
> - right click to pick a point !

## Review the group of peaks

Press Enter to do so... and check the ring assignment

The position of the expected rings is overlaid to the image Un-zoom to view them !

## Acquire some more control points

> - Use the recalib to extract new data-points
> - free/fix/bound then refine

## Visualize the integrated patterns

> - integrate to view the integrated pattern
> - then extract a few extra rings ...
> - the geometry is displayed on the screen

## Quit

All different geometries have been saved into the .poni file. It can directly be used for integration

That’s all.