Dates:April 17, 2015 , Sept. 14, 2015
Frames: 988x180" ISO800
Integration: 49.4 hours
Avg. Moon age: 14.57 days
Avg. Moon phase: 1.88%
Bortle Dark-Sky Scale: 1.00
Astrometry.net job: 1094186
RA center: 16h 9' 25"
DEC center: -23° 51' 39"
Pixel scale: 6.545 arcsec/pixel
Orientation: -179.012 degrees
Field radius: 11.401 degrees
Resolution: 10290x7175
Locations: Maunakea Visitor Information Station, Hilo, Hawaii, United States
Data source: Traveller
This is a 25-frame mosaic. The total exposure time is roughly 50 hr (2 hr per frame). The exposures were collected between 2015/04/17 and 2015/09/14 over 20 different nights.
Three versions are uploaded:
The original (also the final) is a standard version that balances everything.
Ver.B has nebulas more strongly enhanced.
Ver.C has stars removed and nebulas even more strongly enhanced, to show all the complex structure in the gaseous and dusty clouds, and also to show the very faint clouds. Unfortunately it also shows many low level artifacts of my mosaicking, but it's still fun to watch.
The original mosaic contains 600 Mega pixels and it is not practical to upload this image here. The standard version uploaded here is a 0.35x reduction. I know Safari sometimes has difficulty to display large images on astrobin. You may need to use a different browser such as Firefox to see it. Alternatively, you can use this link:
http://gigapan.com/gigapans/187326
to navigate through the 0.5x reduced image.
The total exposure time (50 hr) may sound very long to you. The processing time is even longer. It is probably more than 200 hr, if I include the processing of the preparation images. The image that were taken to prepare for the present one are this:
http://www.astrobin.com/209231/D/
and this:
http://www.astrobin.com/176733/C/
These wide-field images were taken to help to layout the final large mosaic here. They also help to better determine and subtract the sky gradient in the mosaic panels, so a seamless mosaic can be made.
This is one of the most ambitious and time consuming work I had ever carried out in amateur astrophotography.
I hope you enjoy it.
Edit: a newer version can be found here: http://www.astrobin.com/407984/D/
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