Stuart wrote:
Preselector Features is a very important value for increasing the quality of your scans, increasing this has allowed me to reduce the reprojection error value back to 2-4.
After an initial alignment with reprojection error, I run another alignment with reprojection error at 2. Starting off at 2 seems to drop a lot of tie points around the outer portions of the image, with the result that the lens distortion parameters are only effective in the middle of the image. By starting off at 8 you get lens distortion parameters that are better across more of the image, but not particularly great anywhere. This at least gives the second alignment a better starting point for the lens distortion parameters… hence the “coaxing” part of the title.