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Exposure Targeting Set-up for MSI-T for Four holes » History » Revision 8

Revision 7 (Anchi Cheng, 08/16/2016 03:49 PM) → Revision 8/14 (Anchi Cheng, 08/16/2016 03:52 PM)

h1. Exposure Targeting Set-up for MSI-T for Four holes 

 A good way to improve the throughput if there are multiple holes visible in a hl image is to target all four holes. 

 We can set up for 4 holes with this more challenging example: 

 

 h2. About this image: 

 This image shows the edge of the grid bar.    The four holes are reasonably centered. !original.png! 

 !original.png! 

 h2. Leginon/Exposure Targeting/Template> 

 * Cross correlation works better than phase correlation in this case because the hole does not have sharp edge and not perfectly round. 
 * Adjust the value to fill the mean before correlation to minimize the correlation along the edge of grid bar. 
 * Invert template for correlation if needed. 

 !template_corr_settings.png! !template_corr.png! 

 h2. Leginon/Exposure Targeting/Threshold> 

 * Fairly easy to set. 
 !threshold_settings.png! !threshold.png! 

 h2. Leginon/Exposure Targeting/Blobs> 

 * Allow more blobs than the intended 4. 
 !blobs_settings! !blobs.png! 

 h2. Leginon/Exposure Targeting/Lattice> 

 * Similar to that in Hole Targeting/Lattice step. 
 ** Make measurement of the lattice distance 
 ** Estimate the reference intensity for ice thickness filter. 
 !lattice_settings.png! !threshold_with_lattice_measurement.png! !lattice.png! 

 h2. Leginon/Exposure Targeting/Acquisition> 

 * Set up focus template but DO NOT eliminate focus targets using ice thickness criteria.    This works because Leginon (3.1 and above) will automatically choose the center most focus target. 
 !acquisition_settings.png! !acquisition_all_focuses.png!