https://robinwong.blogspot.com/2019/01/olympus-om-d-e-m1x.html
"The hand-held high res shot works differently than the tripod high res shot. The tripod high res shot shifts the pixel in a fixed pattern and combined 8 shots into a composite image. The hand-held high res shot uses very small positional shifts during shooting (following the hand movement) to capture 16 shots and then merged into a composite image. Both tripod and hand-held modes are available in E-M1X and can be activated separately.
Here are the limitations of using the hand-held high res shot versus tripod high res shot:
1) High ISO Limit 6400 for hand-held, 1600 for tripod
2) Aperture smallest F8 for both hand-held and tripod modes.
3) No shutter speed limitations, but the slower the shutter speed, the more difficult it is for hand-held mode and higher chance of camera error
4) Flash cannot be used for hand-held, 1/20 second flash sync limit with tripod
5) Subject movement will result in ugly artifacts for both tripod modes, but hand-held mode is less susceptible to ugly artifacts.
6) 50MP RAW image for hand-held, 80MP RAW for tripod
7) Processing time is longer for hand-held, at about 12 seconds for a single image, about 7 seconds for tripod mode