Giving CCD Blooms the One-Two Punch with MaximDL and the NewAstro DeBloomer Plugin

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.

Blooming Example Pelican Nebula

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 MaximDL’s Bloom Removal tool and Ron Wodaski’s DeBloomer plugin:

Blooming Spikes SBIG ST-10XME

1.  Open the MaximDL Remove Bloom tool

Blooming Spikes SBIG ST-10XME

2.  Select the Automatic button (MaximDL will automatically place a red box around all of the stars it has detected with blooms)

Blooming Spikes SBIG ST-10XME

3.  Because MaximDL will remove not only the bloom but the adjacent star in this case, you must left click the red box around the two stars and select ‘remove’

4. After you click the ‘remove’ button, the red box will disappear

5.  Once the red box is removed, click the ‘OK’ button to perform the first level of bloom removal

6.  Once the first level of bloom removal is done, open Ron Wodaski’s DeBloomer plugin and perform the last stage of the bloom removal on the offending stars


7.  Run the DeBloomer plugin and the end result is both stars are preserved

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