This frame was a mixture of frames taken with and without dual narrow band filter. Density 50% of frame taken with clear filter was on frame taken with dual narrow band filter.
There exist many striae of dark or hydrogen-alpha clouds flowing in the same oblique direction, from east northeast to west southwest or vice versa against the galactic plane. Who know the reason or mechanism of the large structure. North is up, and east is to the left.
Equipment: Sigma 35mmF1.4 DG HSM Art, IDAS NB12 Dual Narrow Band Filter or IDAS clear filter, and EOS R6-SP5, modified by Seo San on ZWO AM5 Equatorial Mount, autoguided with Fujinon 1:2.8/75mm C-Mount Lens, Pentax x2 Extender, ZWO ASI 120MM-mini, and PHD2 Guiding
Exposure: 16 times x 60 seconds, 16 x 240 sec, and 19 times x 900 - 1,800 seconds at ISO 6,400 and f/3.2 with NB12 and 4 times x 60 seconds, 5 x 240 seconds, and 12 x 600 seconds at ISO 1.600 and f/3.2 with Clear Filter
site: 2,430m above sea level at lat. 24 38 55 South and long. 70 16 52 West near Cerro Armazones Chile
SQML was 21.55 at the night. Ambient temperature was around 6 degrees Celsius or 43 degrees Fahrenheit.