Remove flying objects in star trails
In Nebulb it is very easy to get a star trail image with no planes, satellites or meteors, simply by selecting the "Remove flying objects" option before stacking:
Thus, during the stacking of star trails Nebulb automatically performs the removal of flying objects, so that at the end of stacking you get a star trail image completely free of trails of planes, satellites and meteors.
Below, you can see the difference between stacking a circumpolar image in a traditional way (maximum stacking) with Nebulb's automatic flying object removal:
On the other hand, if you look at the selected options of the "Stack" module in the screenshots above, you will see that, in addition to the "Star trails" and "Remove flying objects" options, the "Aligned stars" and "Detect flying objects" options are also enabled. However, although they may seem to be somewhat related, it is one thing to remove flying objects from star trails and another to detect flying objects in an image of aligned stars (to process a meteor shower, for example). In both cases mention is made of flying objects (planes, satellites and meteors), but Nebulb makes a different treatment for each situation. That is, it is possible (and common) to select only the "Remove flying objects" option without stacking "Aligned stars" or enabling the "Detect flying objects" option (this way, the stacking time is much shorter).
In the following image you have an example with the result obtained from a stack of star trails with the removal of flying objects enabled, but without having activated neither the stacking of aligned stars nor the detection of flying objects.
IMPORTANT 1: To achieve the best possible result in the removal of flying objects, it is important that the stars are quite point-like or, at most, form small trails. That is, the longer the trails of the stars in the captured images, the less accurate Nebulb will be able to align the stars and, therefore, the less accurate the software will be in removing only the flying objects (without affecting the stars). For this reason, it is usually a good recommendation to use capture times of about 30 seconds (1 minute maximum), since it is a good compromise between getting images with quite punctual stars, without having to capture an excessive number of images.
IMPORTANT 2: For the removal of flying objects to be applied, multiple images (at least two) must be imported. In other words, the removal of flying objects in star trails cannot be applied to individual images, nor can it be applied to images that have already been composed (such as those obtained using the Live Composite mode of Olympus cameras).
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