[3DEM] F30H objective aperture & low dose

[Bill Tivol]

On Jun 13, 2005, at 2:57 PM, Jamie Riches wrote:

> I was of the understanding that
> this problem was a fundamental one related to the image shifts and the
> objective apertures, but if you find out otherwise, could you please 
> send an
> email to either of the lists?
>
Dear Lists,
	According to David Mastronarde, the problem is inherent in the Tecnai, 
since the obj aper is not in the back focal plane, and the alignment 
procedures do not account for this.
Yours,
Bill Tivol, PhD
EM Scientist and Manager
Cryo-Electron Microscopy Facility
Broad Center, Mail Code 114-96
California Institute of Technology
Pasadena CA 91125
(626) 395-8833
tivol at caltech.edu