“Looks like equirectangular is more suitable for a Milky Way pano. I always hate to see a rectilinear projection. The distortion is just too severe.”
Indeed once the field of view becomes larger than 90 degrees, the perspective distortion in the rectilinear projection becomes rather significant.
“The 2pi sky pano just cover half of the whole sky, or a hemisphere. Looks to me a fisheye or a stereographic projection would be more suitable.”
Okay, i’ll put fish-eye and stereographic projections on my RFC list ;-) to add to the possible projections.
“Another question here. In the normalization page, one can choose to use “add” or “multiply” or “add-scale” or “multiply-scale”. Do you mind explaining their differences? I would think that scaling means multiplication, but it looks like they mean two different things here.”
Yes, normalization can be done for lokation and scale/dispersion of the data.
“add” or “multiply” only normalize the lokation of the data. (additively or multiplicatively)
“add-scale” or “multiply-scale” normalize for both lokation and scale/dispersion.
And yes, the normalization of the scale/dispersion is always done multiplicatively, and relative to the found lokation value.
Cheers,
Mabula