Consistent targeting error triggered by collecting first tomography 'preview' of the hole target
Added by Morgan Beeby about 10 years ago
Hi Anchi,
Our Leginon install continues to work extremely well.
That is, except for one odd problem with targeting. During tomography targeting, 'acquisition' points target perfectly, as does the FIRST set of 'preview' points. However, if I do one set of 'preview' points, all subsequent tomography targets (either 'acquisition', or subsequent 'preview') points are predictably off by approximately a micron. So if after the first set of 'previews' I want to do subsequent previews, or select a tomography target, I need to work out what the newly imposed offset is, and manually 'apply' it by selecting targets that are offset by the appropriate distance. The problem is gone when I move to the next hole target (at least until I 'preview' again).
My tomo and preview offsets both have (0,0) image shift, and my image shift alignments between presets appears great. Our microscope alignment is good and in general very stable.
And, again, 'preview' and 'acquisition' targeting is extremely accurate -- IF I haven't done a previous 'preview' target on the current hole target.
Any thoughts on where to begin troubleshooting this?
many thanks,
Morgan
Replies (2)
RE: Consistent targeting error triggered by collecting first tomography 'preview' of the hole target - Added by Anchi Cheng about 10 years ago
Hi, Morgan,
Thanks for your detailed procedure for reproducing the problem. I will try to reproduce that. However, scope time is hard to come by for me so it might take a few days before I get to this.
You can try this workaround though:
In both "Tomo Focus" and "Tomography", open settings dialog in the respective toolbar. Change the selection for "adjust target using ONE ancestor(s)" to "NO ancestor(s)". It should avoid this problem. The effect you describe indicates a problem of accumulating target adjustment that shouldn't exist. Since "Tomography" target is reached by stage movement with navigator, which itself is a target adjustment, it should be safe to skip this adjustment.
RE: Consistent targeting error triggered by collecting first tomography 'preview' of the hole target - Added by Morgan Beeby about 10 years ago
hi Anchi,
Great. Your workaround sounds promising. I too don't have scope access for a week but this will be the first thing I'll try. Thanks,
Morgan