Hi all,
Graeme's message tell the core of the detector usage notes here at diamond. He might have unearthed a can of worms or two, though ;)
CCDs still are great detectors! I am not sure about his noise comment as the more recent CCDs (post 2000-ish) are designed to operate with anode sources (and definitely image plates have a very good signal-to-noise ratio in long exposures). The mitigation of the readout deadtime is arguably the main experimental design driver when using CCDs.
One other tiny little thing to bring to the surface is that the CCD images presented to the user are not the raw images and my personal opinion is that the end users should be at least aware of what a real image looks like (zingers, taper features, tiling) and their implications in the noise per reflection. I agree that filtering, stitching and smoothing help in judging the quality of the diffraction pattern (and crystal) itself.
Regards,
Jose'
-> try other color scales! black and white is good but a rainbow pallete helps identifying weaks and strongs because if discrete jumps in color at different intensities.
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Jose Brandao-Neto MPhil CPhys
Senior Beamline Scientist - I04-1
Diamond Light Source
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+44 (0)1235 778506
www.diamond.ac.uk
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