Usage

Creating a composite is as easy as loading the desired datasets into the desired slots, and optionally setting the desired composite scheme and exposure lengths.

Care must be taken that all datasets are of the exact same dimensions and are perfectly aligned. Alignment should always be done during stacking (by means of a common reference stack) and never after the fact when the datasets have already been stacked. Alignment during stacking will yield the least amount of errors in point spread functions and chrominance (color) signal, which is important for operations such as deconvolution and color calibration.

The "Luminance" button loads a dataset into the "Luminance File" slot. The "Lum Total Exposure" slider determines the total exposure length in hours, minutes and seconds. This value is used to create the correct weighted synthetic luminance dataset, in case the "Luminance, Color" composite mode is set to create a synthetic luminance form the loaded channels. Loading a Luminance file will only have an effect when the "Luminance, Color" parameter is set to a compositing scheme that incorporates a luminance dataset (e.g. "L, RGB", "L + Synthetic L From RGB, RGB" or "L + Synthetic L From RGB, Mono") .

The "Red/S-II", "Green/Ha" and "Blue/O-III" buttons load a dataset in the "Red File", "Green File" and "Blue File" slots respectively. The "Red Total Exposure", "Green Total Exposure", "Blue Total Exposure" sliders determine the total exposure length in hours, minutes and seconds for each of the three slots. These values are used to create the correct weighted synthetic luminance dataset (at 1/3rd weighting of the "Lum Total Exposure"), in case the "Luminance, Color" composite mode is set to create a synthetic luminance from the loaded channels.

The "NBAccent" button loads a dataset for parallel processing as narrrowband accents (see NBAccent module).

Loading an dataset into the "Red File", "Green File" or "Blue File" slots will see any missing slots be synthesised automatically if the "Color Ch. Interpolation" parameter is set to "On". Note that loading a colour dataset into the "Red File", "Green File" or "Blue File" slots will automatically extract the red, green and blue channels of the colour dataset respectively.

Note that the Red/S-II, Green/Ha and Blue/O-III buttons at the top of the module have alternative designations as well, for use when importing "SHO" datasets. In this case, S-II is mapped to the Red channel, H-alpha is mapped to the Green channel, O-III is mapped to the blue channel.

There are a number of compositing schemes available, most of which will put StarTools into "composite" mode (as signified by a lit up "Compose" label on the Compose button on the home screen). Compositing schemes that require separate processing of luminance and colour will put StarTools in this special mode. Some module may exhibit subtly different behaviour, or expose different functionality while in this mode.

The following compositing schemes are selectable;

• "RGB, RGB (Legacy Software)" simply uses red + green + blue for luminance and uses red, green and blue for the color information. No special processing or compositing is done. Any loaded Luminance dataset is ignored, as are Total exposure settings. This is how less sophisticated software from years past ("legacy") would composite your datasets.
  
• "RGB, Mono" simply uses red + green + blue for luminance and uses the average of the red, green and blue channels for all channels for the color information, resulting in a mono image. Any loaded Luminance dataset is ignored, as are Total exposure settings.
• "L, RGB" simply uses the loaded luminance dataset for luminance and uses red, green and blue for the colour information. Total exposure settings are ignored. StarTools will be put into "composite" mode, processing luminance and colour separately but simultaneously. If not Luminance dataset is loaded, this scheme functions the same as "RGB, RGB" with the exception that StarTools will be put into "composite" mode, processing luminance and colour separately yet simultaneously.
• "L + Synthetic L from RGB, RGB" creates a synthetic luminance dataset from Luminance, Red, Green and Blue, weighted according to the exposure times provided by the "Total Exposure" sliders. The colour information will consists of simply the red, green and blue datasets as imported. StarTools will be put into "composite" mode, processing luminance and colour separately yet simultaneously.
• "L + Synthetic L from RGB, Mono" creates a synthetic luminance dataset from Luminance, Red, Green and Blue, weighted according to the exposure times provided by the "Total Exposure" sliders. The colour information will consists of the average of the red, green and blue channels for all channels, yielding a mono image. StarTools is not put into "composite" mode, as no colour information is available.
• "L + Synthetic L from R(2xG)B, RGB (Color from OSC/DSLR)" creates a synthetic luminance dataset from Luminance, Red, Green and Blue, weighted according to the exposure times provided by the "Total Exposure" sliders. The green channel's contribution is doubled to reflect the originating instrument's Bayer Matrix having twice the amount of green samples. The colour information will consists of simply the red, green and blue datasets as imported. StarTools will be put into "composite" mode, processing luminance and colour separately yet simultaneously. This mode is suitable for OSC and DSLR datasets and is used internally by the "Open" functionality on the home screen when the user chooses the second option "Linear from OSC/DSLR with Bayer matrix and not white balanced".
  
• "L + Synthetic L from RGB, R(GB)(GB) (Bi-Color)" creates a synthetic luminance dataset from Luminance, Red, Green and Blue, weighted according to the exposure times provided by the "Total Exposure" sliders. The colour information will consists of red as imported, with an average of green+blue assigned to both the green and blue channels. This mode is suitable for creating bi-colours from, for example, two narrowband filtered datasets.
  
• "L + Synthetic L from R(2xG)B, R(GB)(GB) (Bi-Color from OSC/DSLR)" creates a synthetic luminance dataset from Luminance, Red, Green and Blue, weighted according to the exposure times provided by the "Total Exposure" sliders and taking into account the presence of a Bayer matrix. The colour information will consists of red as imported, with an average of green+blue assigned to both the green and blue channels. This mode is very useful for creating bi-colours from duo/tri/quad band filtered datasets.