How to make eggy stars appear rounder

Guides, tutorials, tips & tricks.
Post Reply
User avatar
admin
Site Admin
Posts: 2313
Joined: Thu Dec 02, 2010 10:51 pm
Location: Melbourne
Contact:

How to make eggy stars appear rounder

Post by admin »

This question comes up a lot as well, so here is a quick guide on how to make your stars appear rounder in StarTools.
You, again, will need a star mask. This time you'll be interested in all the stars (not just the big/fat/white ones). The 'Stars' preset in the Auto feature of the Mask Editor should help. If you find it is selecting too much stuff that aren't stars, increase the Filter Sensitivity setting. No one image is the same, so just experiment a little. If you have a DSO in your image that is predominantly red or blue, you could optionally instruct the Auto Mask Generator to ignore any red or blue detail by selecting 'Purple (Red + Blue) for the 'Exclude Color' parameter.
Once you're happy with your mask, run the 'Repair' module. This module will help you round your stars.
There are two algorithms that allow you to round your stars. One is the 'Warp' algorithm, which tries to warp your stars back into shape (much like a sculptor moulds a piece of clay). The other one is for heavily distorted stars that look more like patches of light without a distinct core than recognisable stars. The latter is called the 'Redistribute' algorithm. See which one gives you the best result. For both of them to work optimally, the stars in your mask *must* be at least one pixel apart. So if two stars overlap, make sure you 'erase' a single pixel line between them. If you don't do this, you may notice the two stars merge into one big star.
Ivo Jager
StarTools creator and astronomy enthusiast
Post Reply