I've been experimenting with using an Optolong L-enHance light pollution filter while imaging in my urban driveway
and spent a couple of hours last night collecting some data on NGC6960,
the western half of the Veil Nebula. This target is very well suited to
the filter and produced great results with just two hours of data.
Conditions were cloud free, but poor seeing and below average
transparency. The wind was quite high with gusts to 50 km/hour and it
is a testament to my Celestron CGX-L mount that no subs were lost due
to wind induced vibration. The stretch could be pushed further , but I
decided to go for detail instead of the fainted wisps of star stuff.
Click on the
image to see a higher resolution version, then
click again on the image to return to
this page.
The second image is the same target with only three subs taken with an almost full Moon high in the sky. Needless to say, with only 45 minutes of filtered subs, this image
is nothing to write home about and much of the detail was lost to noise
reduction. That said the image compares well to an unfiltered hour long
exposure taken from much darker skies. It is still worth processing these kind of shots as it can be a great learning exercise. More detail on the second image can be found here.
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| 2.5 hours exposure fully processed |
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| 45 minutes processed as a quick test |
| Object |
NGC 6960 Object RA 20:45.7 Dec 30:43 |
| Date |
9 October, 2020 |
| Exposure |
2 hours and 30 minutes (10 X 15 minutes) |
| Conditions |
Bortle 8 skies, high light pollution levels with poor transparency and high wind. |
| ISO |
1600 |
| Camera |
Canon 60Da DSLR |
| Optics |
Prime focus of a SkyWatcher Esprit
120 f/7 APO refractor with a focal length of 840 mm |
| Filter |
Optolong L-enHance |
| Location |
Bedford,
Nova Scotia |
| Processing |
This image was captured using Sequence Generator
Pro, telescope control provided by Mosaic Engine and
processed entirely in Images Plus. Initially an arcsinh stretch
was used to brighten the image enough to see where to crop. The image
was cropped then a starless mask made using the feature mask tool. The
image was split into star and DSO layers using the feature mask and the
DSO layer was noise reduced using a large radius, selective
neighbourhood detail
preserving filter applied with a mask to limit the amount of blurring
applied to the nebula. The stars were then recombined with
the noise reduced nebula image and another arcsinh stretch was applied
using the starless mask made after the first stretch. A slight star
reduction was applied to bring the nebula out more without stretching
it to preserve detail. The image was binned by two for web
download. |
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