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out of range problem during taking grid atlas.

Added by Anonymous over 12 years ago

Hi,

Recently we have changed the camera from 1k to 2k and I did all the calibrations needed for leginon. Finally when taking the images for grid atlas, leginon showed total targets as 67. But some of the targets are eliminated due to X or Y values out of range. It worked well with 1k, I am wondering what went wrong with 2k.

regards,
venkata


Replies (1)

RE: out of range problem during taking grid atlas. - Added by Anchi Cheng over 12 years ago

Hi, Venkata,

My guess is that your 2k camera dimension in image length ( Angstrom/pixel x total number of pixels) is different from that of your old 1k camera. When Leginon uses your atlas radius setting to determine where to acquire images, it aims to cover the circle of that radius. Since you may have by defaul use minimal overlap between gr image, number of images needed to cover the given radius would be different between camera (and magnification). Since the coverage may need to be achieved by having a corner of an image inside the circle, the center of that image where Leginon need to move to acquire it may be way outside the chosen radius like in this figure:

The goniometers we know of can only move 1mm in x,y direction each way, so Leginon node rejects ones that have targets to close to the edge ( at 990 um). Because of this restriction, there is likely lack of some coverage but it should not be be a concern. The two camera just cover the circle differently.

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