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Beam tilt calibration: microprobe vs. nanoprobe

Added by Michael Cianfrocco over 7 years ago

Hello,

We have noticed that once we calibrate beam tilt focusing in leginon in microprobe, it now longer focuses for nanoprobe imaging (and vice versa).

Does leginon save the beam tilt calibration for nanoprobe separately from microprobe? From our perspective, we have to recalibrate the beam tilt each time we want to change the imaging conditions from nanoprobe to microprobe, or microprobe to nanoprobe.

Thanks for your insights into this,
Mike


Replies (8)

RE: Beam tilt calibration: microprobe vs. nanoprobe - Added by Anchi Cheng over 7 years ago

Beam tilt defocus calibration has been beam probe-dependent since 3.0 release. But we ourself don't switch that much. Is this switch within the same session ?

To double check if the last five defocus calibration are probe-dependent, try these python commands in your leginon environment, or look into your database with phpMyAdmin.

from leginon import leginondata
results = leginondata.MatrixCalibration(type='defocus').query(results=5)
for r in results:
  print r['probe']

RE: Beam tilt calibration: microprobe vs. nanoprobe - Added by Michael Cianfrocco over 7 years ago

I also thought that this was resolved in earlier versions as well.

Anyway, I did the test you suggested but I got an error:

>>> from leginon import leginondata
>>> results = leginondata.MatrixCalibration(type='defocus').query(results=5)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'MatrixCalibration

We are running myami/3.2.

Thanks,
Mike

RE: Beam tilt calibration: microprobe vs. nanoprobe - Added by Anchi Cheng over 7 years ago

Sorry,

The table is MatrixCalibrationData, not MatrixCalibration.

Therefore,

from leginon import leginondata
results = leginondata.MatrixCalibrationData(type='defocus').query(results=5)
for r in results:
  print r['probe']

RE: Beam tilt calibration: microprobe vs. nanoprobe - Added by Michael Cianfrocco over 7 years ago

Hi Anchi,

I finally checked the illumination setting and, yes, when I run the above commands I see nanoprobe or microprobe appropriately.

Despite this checking out OK, we still have a calibration problem. Essentially, despite seeing that the defocus calibration is appropriately assigned to a given present (depending on nanoprobe vs. microprobe), we are only able to focus correctly after doing the defocus calibration for a given setting.

To explain, here are the steps we follow:
1) Align microscope
2) Go to Calibrations application (v 3.3)
3) Load presets
4) Perform defocus calibration for 'fa' in Nanoprobe
5) Check Nanoprobe defocus measurement
6) Check Microprobe defocus measurement

What we see is that after calibrating for Nanoprobe, we are able to correctly focus in Nanoprobe. However, we lose the ability to focus using microprobe.

We also see that this problem is reversed if we do a microprobe defocus calibration and then check Nanoprobe focusing.

This means that we can only have one defocus calibration working at any given time.

Any thoughts on how we could further diagnose what is happening?

Thank you for your help!
mike

RE: Beam tilt calibration: microprobe vs. nanoprobe - Added by Anchi Cheng over 7 years ago

Hi, Michael,

Thanks for detailed report. See if this fix it :

In leginon/calibrationclient.py and in the function measureDefocusStig, Look for

    fmatrix = self.retrieveMatrix(tem, cam, 'defocus', ht, mag)

change to this:
    probe = self.instrument.tem.ProbeMode
    fmatrix = self.retrieveMatrix(tem, cam, 'defocus', ht, mag, probe)

Looks like even though the probe is recorded but it was never used in the query part. If this fixes your problem, I will create a proper patch.

RE: Beam tilt calibration: microprobe vs. nanoprobe - Added by Michael Cianfrocco over 7 years ago

Thank you Anchi for the prompt response. That did it! We are now able to do use either imaging mode and the automated focusing works.

mike

RE: Beam tilt calibration: microprobe vs. nanoprobe - Added by Anchi Cheng over 7 years ago

Good to hear. Sorry about the bug.

RE: Beam tilt calibration: microprobe vs. nanoprobe - Added by Anchi Cheng almost 7 years ago

Proper bug fix is handled in Issue #4894 and probe requirement extends to all beam tilt and focus related calibrations.

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