Manual Registration
When automated registration algorithms fail because stars are not easily detected (too elongated or too faint for example), it is possible to align images manually with this tool. It only supports translations.
Two display areas at the bottom of the registration tab can be configured to show the reference image and the currently loaded image in transparency, and the shift between the two can be easily changed to values that will make the images appear best aligned.
Click on 'Set first preview' or 'Set second preview' to select the area to configure; then click in the image at the position where you want the center of the preview display to be positioned. It is a good idea to use both preview displays and put them apart as much as possible in the image to see the possible effect of geometric aberration and to provide a better precision in the alignment.
Once the preview areas have been positioned, load the reference image to enable its display in the preview areas. Then, when loading other images of the sequence, the reference image will be displayed in 50% transparency in the preview areas.
Tip
The mouse wheel or up or down and left or right arrows can be used to perform the translation in x or y. Simply select first the axis of movement by clicking in X translation or Y translation entry field when the mouse wheel is used.
Move each image to align it as well as possible with the reference image. This shift information will then be saved in the sequence metadata file (.seq) and be used during stacking like any other translation registration data.