Hi Sjors and all,
I re-run an old dataset now following the protocol for relion-1.3
(using autopicking and the new ctffind4) and noticed that the defocus
values output by the two versions of ctffind were quite different (see
example of one micrograph below):
ctffind4:
# Columns: #1 - micrograph number; #2 - defocus 1; #3 - defocus 2; #4 -
azimuth of astigmatism; #5 - cross correlation; #6 - spacing (in
Angstroms) up to which CTF rings were
detected
1.000000 30174.35 30167.60 838.7715 0.2366101E-01
18.90870
ctffind3:
DFMID1 DFMID2 ANGAST CC
20262.43 20335.00 58.02 0.19150 Final Values
In addition, whereas the observed and estimated quarter-Thon-rings
coincided very well in ctffind3 they did not so in ctffind4 and the
final resolution obtained from the same dataset was by about 4 A less.
what might be wrong?
Thanks, Dieter
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Dieter Blaas,
Max F. Perutz Laboratories
Medical University of Vienna,
Inst. Med. Biochem., Vienna Biocenter (VBC),
Dr. Bohr Gasse 9/3,
A-1030 Vienna, Austria,
Tel: 0043 1 4277 61630,
Fax: 0043 1 4277 9616,
e-mail: [log in to unmask]
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