|Scope, mount, camera:||12.5" Newtonian, f/5.1, MAM50, ST-10XME|
|Filter, exposure time:||LRHaGB, L = 17*300s and 5*600s, RGB=(7x4x12)*600s, Hα=5*1800s
|Total exposure time:||8h35min|
|Location:||La Palma, Roque de los muchachos|
|Comments:||Image seeing: 2.0"
Data reduction with THELI, colour composition in PS.
The Hα-layer was blended with the R-channel before the creation of the RGB.
I corrected the colour weighting factors for about 60% of the galactic extinction in this field. A full correction would imho have imbalanced the colours of the foreground stars too much to the blue side. The differential extinction factors for the blue and the green filters with respect to the red filter are about 2.3 and 1.4, respectively (see NED).