All,
As a follow-up to my questions in a recent thread (the Horsehead taken with a Borg 77), here's my take on H-alpha imaging. I thought I'd try a totally different approach with my workflow, and when I compared the results with one done using the "Curves and Levels" approach of Photoshop, they were remarkably similar (even the shape of the histogram).
This is IC405, the Flaming Star nebula.
Imaged with a Borg 76ED on a Takahashi EM200 mount last October 29th.
SBIG ST-8XE
Cust-Sci 4.5 nm H-alpha filter
11 x 20 minute exposures binned 1x1
Processing flow:
In Maxim:
Median combine
DDP
Gamma stretch
High Pass filter restricted to brighter pixels Low Pass filter restricted to dimmer pixels
In Photoshop:
Some levels and curves
Noise Ninja
Gaussian blur to the whole image (0.5)
Further Gaussian blur to the grainier selection Dimming of the grainier selection Unsharp mask to the entire image
It's still dimmer than similar shots of this region I've seen taken with H-alpha, but pushing it any farther either brings out lots of grain, or the "graying effect" that I alluded to in my other post.
Anyway, comments and suggestions will be appreciated.
Eric
As a follow-up to my questions in a recent thread (the Horsehead taken with a Borg 77), here's my take on H-alpha imaging. I thought I'd try a totally different approach with my workflow, and when I compared the results with one done using the "Curves and Levels" approach of Photoshop, they were remarkably similar (even the shape of the histogram).
This is IC405, the Flaming Star nebula.
Imaged with a Borg 76ED on a Takahashi EM200 mount last October 29th.
SBIG ST-8XE
Cust-Sci 4.5 nm H-alpha filter
11 x 20 minute exposures binned 1x1
Processing flow:
In Maxim:
Median combine
DDP
Gamma stretch
High Pass filter restricted to brighter pixels Low Pass filter restricted to dimmer pixels
In Photoshop:
Some levels and curves
Noise Ninja
Gaussian blur to the whole image (0.5)
Further Gaussian blur to the grainier selection Dimming of the grainier selection Unsharp mask to the entire image
It's still dimmer than similar shots of this region I've seen taken with H-alpha, but pushing it any farther either brings out lots of grain, or the "graying effect" that I alluded to in my other post.
Anyway, comments and suggestions will be appreciated.
Eric
Attached Image:
