Leginon

Hi all,

I am having a major problem with controlling image shifts on the CM. I think that the CM must control image shifts much differently than a Tecnai. Here is a description of the symptoms:

1) If I'm in Navigator, I can navigate by image shift and everything works like you would expect. I can click on an object in the image and it will center that object with reasonable accuracy. This indicates to me that nothing is wrong with the image shift calibration.

2) Let's say that I use the traditional way to align presets, i.e. center some object in fa and use Navigator to center that object by image shift in hl, sq, and gr. As I said in 1), the centering in Navigator will work just fine. When I do a "from scope" in Preset Manager, the value for image shift changes, indicating that it is getting the parameters from the scope. If I use Preset Manager to cycle the presets after aligning them, however, the image shift will be WAY off. What is more, it would get worse every time that I cycled the presets.

3) If I sent a preset with image shift > 0 to the scope then manually correct the image shift on the microscope then do a "from scope", the value for image shift in Preset Manager will change. But the problem will still persist if I send the new preset to the scope again.

4) I can get Preset Manager to work properly by doing the following. Send a preset with an image shift of 0 to the scope. Manually change the to a lower magnification. Manually adjust the image shift. Do a "from scope" with a different preset, for instance hl. Now the image shift will read zero in Preset Manager but somehow the microscope will remember the proper image shift. If I then use Preset Manager to cycle the presets, they will stay aligned.

Any guesses as to what is going on?

Thanks,

Scott