Telescope: Meade 10” LX200 SCT (Wide Field) @ f/6.3, Orion Atlas EQ-G
Camera: Full-spectrum Modified Canon 600D (Rebel T3i)
Filter: Orion Imaging Skyglow Filter
Guide scope: Astro-Tech 60mm, Meade DSI Pro II, PHD
Exposure: 38x120sec, ISO 1600 saved as RAW (Dithered every 4 images)
Darks: Internal (Long Exposure Noise Reduction On)
Flat: 32x5sec, ISO 1600, LED tracing tablet, plus a synthetic flat
Average Light Pollution: Red zone, poor transparency, passing high clouds
Lensed Sky Quality Meter: 18.5 mag/arc-sec^2
White Balance: Nebulosity Automatic
Software: Backyard EOS, Deep Sky Stacker, Nebulosity, Photoshop
I was very surprised at how well this image turned out. After a very clear day, the evening turned cold with high relative humidity and a veil of high altitude haze flowing overhead. I lost about half of the source images to very poor sky conditions. One challenge of these conditions is that the source frames can be uneven; giving an odd gradient that cannot be corrected with a simple flat. To remove the residual gradient I used an old method of creating a synthetic flat. Briefly, you carefully delete the stars and object, filling them in with the nearby background, and then using a median filter to smooth things out, closely matching the average background gradient. Applying this as a flat usually evens everything out quite nicely.
This was the first test image taken with my ‘new’ 10” f/6.3 LX200. Since my first 10” f/6.3 (from LX200 GPS production) is configured specifically for imaging, I was planning one configuring this one for visual and electronic assisted astronomy, but I couldn’t resist at least giving it a test run with my DSLR on it, and I am delighted with how well it performed, particularly given the challenging conditions. If you look closely, you can see that the background is peppered with little background galaxies.