Part 2: calibrate, register, normalize & integrate the individual mosaic panels of the Mosaic Tutorial – Milky Way to Rho Ophiuchi by Mabula

Below, you can find the data processing settings that I used for the mosaic panels of both the 135 & 400mm data:


I have adjusted this a bit due to the very
high number of stars in Stefan’s images. This is due to
the excellent conditions in Namibia at time of exposure
and the long exposure lengths. The widefield data,
especially at 135mm is just full of stars

minimum star size = 10-20 (we favor the biggest stars
to use for analysis and registration, this really helps
when the data is full of stars like this…)

or enable the out of focus? FWHM > 12pixels setting to
reduce the star count, does help in this case

minimum stars 2000
maximum stars 4000

For data with longer focal lengths and not so dense star fields.
The default settings in 3) are fine.


All default, only enabled Distortion Correction in case
of bad registration RMS (Bad is larger than 0.5 pixel).
So check the results after registration.




Since we have less than 10 frames per panel, we
integrate with median integration.

weights: quality, since we have different exposure
lenghts, the images with higher star counts and better
SNR will have higher weights, slightly offset by
increased star FWHM sizes.

LNC: 1st degree 3 iterations
MBB: 5%

No Outlier rejection, unless needed due to artefacts.
The Bad Pixel Map of the Nikon D810a takes care
of all Bad/Hot Pixels in calibration.