Hi I’ve never actually used it in anger (one should never be angry when processing data…), but doesn’t AutoProc, developed by the good folks at Global Phasing do a lot of these analyses? Clemens, Claus etc may have something pertinent to say.
Harry > On 30 Oct 2023, at 13:23, Jorge Iulek <jiu...@gmail.com> wrote: > > Dear all, > > I have found many fundamental studies on image processing and > refinement indexes concerning the decision on cutting resolution for a > dataset, always meant to get better models, the final objective. Paired > refinement has been a procedure mostly indicated. > I have been searching studies alike concerning, in these days of > thousands of collected images and strong x ray beams, the cutting (or > truncation) of the (sequentially due to rotation method) recorded images in a > dataset due to radiation damage. Once again, I understand the idea is to > always produce better models. > On one hand, the more images one uses, the higher the multiplicity, > what (higher multiplicity) leads to better averaged intensity (provided > scaling makes a good job), on the other hand, the more images one uses, lower > intensity (due to the radiation damage) equivalent reflections come into play > for scaling, etc. How to balance this? I have seen a case in which truncating > images with some radiation damage led to worse CC(1/2) and <I/sigI> (at the > same high resolution shell, multiplicities around 12.3 and then 5.7), but > this might not be the general finding. In a word, are there indicators of the > point where to truncate more precisely the images such that the dataset will > lead to a better model? I understand tracing a sharp borderline might not be > trivial, but even a blurred borderline might help, specially in the moment of > image processing. > I find that in > https://ccp4i2.gitlab.io/rstdocs/tasks/aimless_pipe/scaling_and_merging.html#estimation-of-resolution > there is a suggestion to try refinement with both truncating and not > truncating. > Sure other factors come into play here, like diffraction anisotropy, > crystal internal symmetry, etc., but to start one might consider just the > radiation damage due to exposure to x rays. Yes, further on, it would be nice > the talk evolves to those cases when we see peaks and valleys along the > rotation due to crystal anisotropy, whose average height goes on diminishing. > Comments and indications to papers and material to study are welcome. > Thanks. > Yours, > > Jorge > > ######################################################################## > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > > This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing > list hosted by www.jiscmail.ac.uk, terms & conditions are available at > https://www.jiscmail.ac.uk/policyandsecurity/ ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
