| Scripting Resources for DigitalMicrograph™ |
CCD Electron Calibrator |
|
Function |
Applies previously determined intensity scaling values to images, to calibrate them in electrons or electrons per unit area. It requires that the conversion efficiency of the CCD be either known or measured. |
Version |
version:20140328, v1.0 |
Author |
D. R. G. Mitchell |
Acknowledgements |
Thanks to Gilberto Casillas-Garcia for assistance with the current measurements. |
Comments |
Script to apply intensity scaling (convert counts into electrons) to images previously acquired. These images can be either open or contained in a folder of files on a disk. The Conversion Efficiency (number of counts per incident electron) needs to be known. This information is supplied with your camera. However, it is usually only reported at one voltage - and it changes with voltage. You can measure this value yourself by measuring the current in a known probe and then exposing the CCD to the probe. Typical values are around 5 counts per electron at 200kV and perhaps double that at 80kV. However, it will vary, even between identical cameras and the type of scintillator will make a big difference. The values measure here on a GIF Ultrascan camera, were twice those of the bottom mounted Ultrascan due to differences in the scintillator type. |
System Requirements |
Should be compatible with all recent versions of DigitalMicrograph. |
Known Issues |
As set up, the script has values in places for two different cameras at two different voltages. However, provision is made for up four of each. Camera/voltage data can be edited in the Global Tags (once the script has been run once). |
Supported |
Yes |
Included Files |
Main script file. |
Source Code |
See attached script |