[3dem] VPP phase development curve

[jamon]

Dear Lister,

Does anyone calibrated the VPP phase development curve during data 
collection, using ctffind4.1.x or gCTF? I ran some test on Krios and 
notice the phase changes rapidly from 0 degree to 90 degree with less 
than <500e/A2, then reach 120 degree at 1000e/A2. Later the phase shift 
moves much slower from 120 degree to 140 degree within 5000e/A2. It 
suggest that the usable dose window is very narrow. Is there a way to 
control phase shift stable at 90 degree instead of 120 degree? Your 
suggestions are appreciated in advance.

Thanks and Regards,

Jian