When imaging with a CCD camera with a high quantum efficiency (QE), such as the SBIG ST-10XME with the KAF 3200ME chip, you sometimes have to deal with some very nasty blooms. Due to the ST-10XME lack of antiblooming gate, light from bright stars overwhelm the full well capacity (electron holding capacity) of the pixels on which they are being collected, resulting in excess electrons spilling over into adjacent pixels. In other words, the light-gathering pixel exceeds its capacity to hold captured photons which yields stars that have irregular diffraction spikes, as seen in the image below.
Sometimes, the blooming can get so bad that you must take special care to preserve the stars and the detail. During bloom removal, sometimes the excess electrons can spill over onto other stars and destroy them, ruining your star field. I use MaximDL’s bloom removal tool but sometimes that tool removes more than just the blooms. There is also an DeBloomer Plugin for MaximDL created by Ron Wodaski, which contains both automatic and manual tools that remove blooms. The nice aspect of the DeBloomer plugin is that it performs a batch process on all your images. I recently learned, while processing subs from M31, that the MaximDL bloom removal tool was not sufficient enough to preserve the stars when the blooms from an adjacent star spilled over onto it. Here is an example:
Here is a two step process for dealing with these types of blooms while preserving adjacent stars using ...Read More >