I received the following explanation from DJI Support when asking why the Mavic 3 Enterprise has such significant vignetting:
The Mavic 3 Enterprise is designed to cater to the needs of surveying and mapping professionals, who usually prefer to have vignetting present in their images. This is because the vignetting provides valuable information about the orientation and distortion of the photograph, which can be useful for post-processing and accurately mapping the area. We only recommend to activate the dewarping the aircraft is not used in a mapping applications.
I’m very puzzled by this statement, and I can’t make sense of how vignetting helps with calibrating(?) images or post-processiong (whatever that is) or anything else, to be honest.
Can anyone help me?
What DJI states is correct, is better to let photogrammetry to estimate the internal parameters.
Hence if you are mapping with the M3E, turn dewarp off.
I would have thought that the calibration is optimized for “normal”, non-vignetting cameras and can’t make a profit from it. Also all very dark or even black points are lost pixels, I thought.
I struggle to understand how vignetting could help as well. I can understand not to dewarp, but darkened edges to improve calibration sounds like a stretch. My interpretation of vignetting also includes an obstruction that causes the darkening. This would be detrimental to the image quality. Maybe this is an incorrect assumption in this case?
Looks like something to study over the holiday break.
Thanks so much Jonathan for your thoughts.
It is not a question of shading in this case, no. It’s really that the M3E (Mavic 3 Enterprise), like the P4 RTK for years already, have this uncorrected (“warped”) mode that is perceived as distortion because straight lines appear bended.
However, I confess that there may well be something about this uncorrected mode that is advantageous for photogrammetric purposes, since the raw pixels are probably less manipulated.
The GSD will be slightly lower though, since in the raw/warped mode a slightly larger angle is captured. However, this can usually be compensated with a slightly lower flight altitude.