Dear Dieter,
It seems in this case ctffind4 failed where ctffind3 succeeded.
So far, the only times ctffind3 performed better than ctffind4 was when
dealing with digitized film micrographs - is this the case here? If not
(i.e. if this is a ccd/cmos/direct-detector dataset), would you mind
sending me the micrograph so I can debug ctffind4?
Many thanks
Alexis
On 01/20/2015 05:40 AM, Dieter Blaas wrote:
> 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
>
> ------------------------------------------------------------------------
> 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]
> ------------------------------------------------------------------------
--
Alexis Rohou
Research Specialist
Grigorieff Lab
http://grigoriefflab.janelia.org
Tel. +1 571 209 4000 x3485
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