Author Topic: PictureSnapApp sample holder images  (Read 966 times)

Probeman

  • Emeritus
  • *****
  • Posts: 1875
  • Never sleeps...
    • John Donovan
PictureSnapApp sample holder images
« on: February 10, 2018, 09:33:02 am »
This topic is for those who would like to share high resolution images of their SEM/TEM/other sample holders. I'll start by sharing an image and the calibration file for our FEI Quanta pin stub holder. See attached files below (remember to login to see attachments).

Note that I scribed a triangle on the holder surface for ease in calibration.  In our lab the convention is to always use three calibration points to correct for sample rotation (though in actual practice, with PictureSnap and PictureSnapApp one generally begins with a simple two point diagonal calibration just to get the stage roughly calibrated before switching to the three point calibration!).  Therefore we always start with a location at the top of the triangle (12 o'clock) for the first calibration point, then a second calibration point on the 2nd triangle corner in the lower right (going clock-wise). 

Once the image is calibrated using two points, we can navigate to the third calibration point in the lower left and switch to three calibration points and get the image calibrated exactly.

But it should be noted only two points are required and any features on the sample can be utilized for the calibration points, so long as they can be found in the instrument's imaging system.
« Last Edit: February 10, 2018, 12:53:15 pm by Probeman »
The only stupid question is the one not asked!

Probeman

  • Emeritus
  • *****
  • Posts: 1875
  • Never sleeps...
    • John Donovan
Re: PictureSnapApp sample holder images
« Reply #1 on: April 03, 2018, 01:24:50 pm »
It's so easy to perform these sample image calibrations that everyone should just do it themselves, but just for fun I attach images and calibration files for our 6 hole and 2 + 2 thin section sample holders from our Cameca.

If you do download these files to use with the PictureSnap feature in Probe for EPMA or in our new PictureSnapApp, you probably want to "touch up" the stage calibration but they should be really close for general navigation... however, please note that since we scribed some scratched lines on our sample holders to make it easier to calibrate the image, if you do update the stage calibration using these images, you'll probably have to choose some other "landmarks" to calibrate to, because these scribe marks won't be available on your sample mounts.

Edit by John: another thought:  since the scratch marks we made on the sample holder are about 500 um higher in Z than the sample surfaces themselves, after getting the X/Y calibration done, we simply found the approximate Z stage position for the samples themselves and then just pasted that Z value in for all three point calibrations, and then clicked the Calibrate Image button again.

Of course if you're working on an actual sample that you scanned or took a picture of, you'd utilize the actual Z values for that sample and then small changes in sample height/tilt are automatically compensated for.
« Last Edit: April 03, 2018, 01:36:33 pm by Probeman »
The only stupid question is the one not asked!