Patch Motion Correction with Falcon Camera and Blank Last Frame

Motion Correction
1

I have occasionally seen a result in Patch Motion correction where the last few frames show very large shifts. See attached example.

Screen Shot 2020-05-04 at 4.45.15 pm
Screen Shot 2020-05-04 at 4.45.15 pm710×710 15 KB

It seems to happened regularly, but in a random fashion. Has anyone seen this before? I am trying to understand if this is a real attribute of the data, or a caveat of the Motion correction. The other movies in the dataset correct as expected.

Thanks!

-Simon

2

Hi @simonbrown,

What type of camera is this? The falcon cameras had a bug in some EPU version where the last one or more frames would be completely blank, that caused this kind of motion trajectory to be estimated

3

Yes, it is a Falcon camera. And your interpretation is correct. If I remove the last frame from motion correction it looks fine.

Thanks!

5

I also have this issue with a Falcon3 camera (last 5-7 frames have very high linear drift), when processing movies using patch motion in CryoSPARC. However, the last frame/s is/are not blank (verified by looking at them using relion_display).

Which versions of EPU are known to write these “defect” movies?