For practical purpose, synthetic luminance generation assumes that, besides possibly varying total exposure lengths, all other factors remain equal. E.g. it is assumed that bandwidth response is exactly equal to that of the other filters in terms of width and transmission, and that only shot noise from the object varies (either due to differences in signal in the different filter band from the imaged object, or due to differing exposure times).
When added to a real (non synthetic) luminance source (e.g. the optional source imported as 'Luminance File'), the synthetic luminance's three red, green and blue channels are assumed to contribute exactly one third to the added synthetic luminance. E.g. it is assumed that the aggregate filter response of the individual three red, green and blue channels, exactly match that of the single 'Luminance File' source. In other words, it is assumed that;
red filter response + green filter response + blue filter response = luminance filter response
If the above is not (quite) the case and your know exact filter permeability, you can prorate the filter response by varying the Total Exposure sliders.
Finally, in the case of the presence of an instrument with a Bayer matrix, the green channel is assumed to contribute precisely 2x more signal than the red and blue channels.
Any narrowband accent data loaded, does not impact synthetic luminance generation.
You will notice this workflow is substantially similar to any other StarTools workflow, even though we are dealing with a complex composite of luminance, synthetic luminance, and color data all at once.
The primary goal that the Color module was designed to accomplish, is achieving a good colour balance that accurately describes the colour ratios that were recorded.
It is important to understand that the signal as show during this first stage, is merely signal that is up for consideration by the second stage.
The crop module is an easy-to-use image cropping tool with quick aspect ratio presets and switchable luminance, chrominance and narrowband accent preview modes.
The button allows you to switch the view between the luminance, chrominance and narrowband accent datasets that are being processed in parallel.
You can convert everything you see to a format you find convenient. Give it a try!