Ou-4 and Sharpless 129 - RGB and OIII + Hα (complete)
The combination of Hα SII and OIII with RGB is more or less similar to the combination with Hα, OIII and RGB only. SII emission is very weak but strongly correlated with Hα emission
Fourteen nights in August / September 2016
Images taken with two setups:
(1) Skywatcher Esprit Apo 80/400 mm with flattener,
(2) TS Apo 60/260 mm with reducer,
Both telescopes on Mesu 200 mount
(1) Nikon D5100a DSLR, ISO 200, 150x300s+71x240s+103x180s (overall 22h23m)
(2) MI G2-8300FW CCD camera @ -25°C, Hα (6nm): 1x1500s + 15x1200s; Hα (12nm): 46x900s (overall 16h55m); SII (12nm): 68x900 (overall 17h00m); OIII (12nm): 132x900s (overall 33h00m) overall exposure time 89h18m,
Rhein-Main area, Germany
North is on the right side of the image