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Friday, November 18, 2011

Butterfly to Crescent, a new Cygnus project started

A two panel mosaic from the Hydrogen alpha emission.
NOTE. the "Noise" in the background is not a noise but a countless amount of stars!

Last night I was able to shoot two panels in H-a for a new imaging project from Cygnus. At upper left the Butterfly nebula and in middle, the Crescent Nebula.
Clouds rolled in before I was able to shoot any other channels, so colors will follow later.
Canon EF 200 mm at f1.8 is an extreme fast lens to collect photons, only one hour of ten minute subs per panel was needed for good signal to noise.

A closeup to show the resolution.

I just noticed, that this new panorama and my previous project, Cirrus of Cygnusare overlapping!
I hadn't purpose to build a large mosaic but since they are overlapping, in some parts, I will make one.

QHY9 camera is a very good match with wider field camera lenses due the smallish, 5,4 microns, pixel size.
Nowadays  I', processing all under sampled images, like one above, up-scaled 200% to maintain the smallest possible details.  It needs a lots of memory and the processing gpower though! A single, up-scaled gray scale FIT-format, image will take about 500 meg to handle (32bit floating point), usually there are more than a dozen of them...

A gray scale two panel mosaic with my previous project.

Technical details:

Processing work flow:
Image acquisition, MaxiDL v5.07.
Stacked and calibrated in CCDStack2.
Deconvolution with a CCDStack2 Positive Constraint, 33 iterations, added at 40% weight
Levels, curves and color combine in PS CS3.

Optics, Canon EF 200mm camera lens at f1.8
Camera, QHY9
Image Scale, ~5 arcseconds/pixel
Guiding, Meade LX200 GPS 12" and a Lodestar guider
Filter, Baader 7nm H-alpha
Exposures for two panels,
Panel 1, 6x600s Binned 1x1
Panel 2, 6x600s Binned 1x1

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