Search for the defocus value
Sample: single EM of copper chlorinated phthalocyanine with ED data

The procedure is the same as that for K2O.7Nb2O5, except that when the following dialog box appear, select 'Electron Diffraction Data File' instead of 'Electron Micrograph' and specify the full path of the diffraction data file. This file should have an extension ' .dhk'.

The result (the figure below) is a set of curves showing the variation of figures of merit with trial defocus values.

Comparing the result with that for K2O.7Nb2O5 (the next figure)

we see that, in the case of chlorinated copper phthalocyanine, the combined figure of merit (yellow curve) gives a much prominent indication of the possible defocus. This is due to the use of additional information - electron diffraction data. The flat area of curves near the defocus value of - 400Å for chlorinated copper phthalocyanine is due to the fact that the electron microscope image was taken near the optimum defocus and, the change of defocus value is not sensitive to the image intensity in this area. Actually we can use any defocus value between - 25 and - 55 and get nearly the same deconvolution result.