Dear Panel:This effect (changing saturation of blue in the sky) looks to me to be similar to the effect I get when making Panos using an SLR and a circular polarizer lens filter. Are you sure that the ND filter you are using are not polarized?
Firstly, I thank you all for joining in to try to help me understand why I am getting this dark shadow at the top with my Mavic 2 Pano images. Taking everything into account, I repeated a tested today. I took 4 shots. Two shots with the Freewell Variable ND filter set at 6. Shot (1) with Variable ND set on PANO (2) shot 2- no pano- just a regular shot, with The VARIABLE ND FILTER ON .
Then I brought the drone back down, took off the variable ND filter, placed the factory lens cover back on, then put the drone back up and re-shot, (3) PANO with Variable ND filter. and (4) regular shot (not pano) with no filter.
As you can see, the shadow is not visible without the variable ND filter.
This filter is not a polarizing filter.
Should I just stop using the variable filter and go for the regular ND filters (4-8-16-32,etc.)???? Following are 4 pictures- Pano with Variable ND,Pano without ND filter, regular with Variable ND, and Regular without ND filter.