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Acquiring summed frame image thru Leginon » History » Version 5

Anchi Cheng, 06/18/2012 08:48 PM

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h1. Acquiring summed frame image thru Leginon
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h2. Camera Configuration
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Refer to [[DE-12_introduction#Camera_Settings_for_DE-12|introduction]] on the options
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# Select DE12 as the camera
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# Uncheck "save raw frames"
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# Leave "Frames to use" empty to sum up all frames
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h2. acquire [[Bright and Dark reference images]]
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** Leginon does not research references by frame rate and sensor temperature.  If you change either of them, you will need to acquire new references.
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** Use valid exposure time (multiple of frame time length)
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** *Use long positive readout delay time (>= 2 frame length) to ensure uniform intensity readout on the first recorded frame.*
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** It does not matter whether you save raw frames or not in this process.  Leginon does not use them for corrections.
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h3. typical number of dose rate, number of frames, number of images used in reference image acquisition at NRAMM
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We have been using the following numbers.  However, we did not do a systematic study on what is required, so it might not be optimal:
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* dose rate: 4 electron per pixel per frame (similar to our typical dose rate for experiment)
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* number of frames in summed image: 10 (i.e. 407 ms if using the default 24.57 frames/second)
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* number of images for averaging: 20
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h2. Usage
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# Select DE12 as the camera, configure and uncheck "save raw frames" in the camera configuration of the preset that you want to use and go for it.