![]() ![]() In total, the camera collected 15.5 hours of light and I am happy with the result. Let’s keep the focal length 180 mm and let’s have a look at the left star Deneb and very famous North America nebula:Īgain, let’s keep the focal length 180 mm and change to perspective to the bottom (eastern) star Aljanah, where the beautiful supernova remnant the Veil nebula is located: ![]() Let’s zoom further to the central star Sadr by change of the lens to 180 mm focal length: Here the constellation is perfectly centered: Let’s zoom a bit by changing the lens to a 50 mm focal length. Let’s have a look at a wide-field picture captured by a 24 mm lens attached to Canon EOS 6Da: It is located visually on the plane of the Milky Way galactic disk, therefore there are many deep space objects. For example constellation Cygnus, which is sometimes called the Northern Cross. However, there are some regions full of stars and deep space objects. Obviously, if you are in a dark place, you can point your camera nearly anywhere. Then I started to think about the next objects. The primary target was Rho Ophiuchi, which I captured really well. Couple of false starts there.I went to Crete without a detailed plan on which deep space objects to capture. I spent a while figuring out how to do the stretch without blowing out the galaxies. The only place where I had to go back and redo a couple of times was 8 & 9. Seems complicated when I write it down, but it all flows quite naturally. PixelMath to combine the two images using the max(starless, star_mask) function to choose the brighter of the two pixels at each position.ArcsinhStretch on the star mask to stretch and boost colour.HistogramTransformation to get a black point I was happy with.GeneralizedHyperbolicStretch to reach a final stretch I was happy with.Then imported mask back into Pixinsight and applied to the nebula image. As the outer layers of the galaxies were the same brightness as parts of the nebula, I imported the range mask into a paint program, and painted out any nebula and the halo of the bright star 44-Serpens so I would only protect the galaxies. RangeSelection to create a mask that would protect the galaxies in the field.MaskedStretch to see what I am looking at for further stretches.EZ-Denoise gives about the same result to my eyes, but NoiseExterminator is faster I am trialling NoiseExterminator at the moment. NoiseExterminator on the nebula image to reduce colour noise in the background.Starnet2 to remove stars and create a star mask.SpectrophotometricColorCalibration to adjust colour balance using a preview of part of the image I felt was genuine sky as the background reference.BlurExterminator to control stars - I was using a 300sec exposure so stars got a bit big.DynamicBackgroundExtraction to get rid of gradients.If I remember, the processing went something like this:īasic calibration and stacking using WBPP This is one-shot-colour so we are RGB all the way through. However, even here only about half the subs were usable due to high thin cloud (that plays merry hell with faint nebulae).Īll processing was done in Pixinsight. The data is good as I am using a remote observatory in the mountains of southern Spain ( rather than my cloudy, murky backyard in North Wales.
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