7 Extra Note

It is worth mentioning that one likely needs to calibrate the Standard Focus separately for GIF camera.

When specimen is at Eucentricity, if objective is precisely focused for one camera, it is also focused for all the pre-GIF camera. Indeed, we don't need to worry for different cameras which are at different level post-column. But this is no longer the case for a post-GIF camera. For a GIF camera, due to extra lens system of GIF, one have to focus differently so that it is focused at GIF camera position. This is why we have to calibrate the Standard Focus separately.

As current version of SerialEM, this Standard Focus calibration doesn't have camera ID. It only has magnification index. One has to have two different calibration files, if there are some overlapping magnifications needed for both camera. Hopefully, David will allows the camera ID included for this in the next version of SerialEM.

Usually, the calibration is accurate enough to get specimen close to eucentric quickly, and within a few microns. If you want to be more accurate, or you might want to do it at higher mag like that of record mag. It is the best to calibrate this value yourself in your session, as an user, because you might be using a alignment parameter slightly different from what was when calibrate globally.