September 29, 2014

Bi-Color Eastern Veil Nebula, NGC 6995 - September 2014

Full resolution image here.

Here is the same veil as below with 220 minutes of OIII added.  The green is synthetic (80% OIII and 20% Ha).  I have seen bi-color images in which the OIII shines as blue, but my blue channel here is too weak.  Whether from the lower blue response of my camera, that I do not have enough time on OIII, the reddening of the sky above my light-polluted backyard, or all of these, the Ha overwhelms the blue. The night I collected OIII was also pretty hazy.  The effect of the blue in this image is therefore only to lighten/whiten the red.

Telescope: Astro-Tech AT111EDT and William Optics AFR-IV (eff. at f/5.6)
Camera and Exposure: SXVF-H9  Ha: 12x1200" (6nm Ha) + 12x900" (12nm Ha+NII); OIII: 11x1200".  Alnitak Flat-man flats
Filters: Astronomik 6nm Ha, 12nm OIII
Guiding: SX Lodestar and SX OAG
Mount: Takahashi NJP
Software: Nebulosity, Photoshop CS3, Registar
Location: The Woodlands, TX