My first attempt at H-α imaging. Conditions were marginal at best; it's monsoon season so there were clouds and wind gusts as there were thunderstorms around. Synced on λ Sag and easily found M8 with the PicGoto; use of the PicGoto is becoming routine. Focusing with the H-α filter was interesting; the stars are so small that it is hard to use the half flux radius, so mostly I just eyeballed it. M8 did turn out to be a good target for this first try. Because it is so bright, 300 s subframes were sufficient (and actually just about right). While waiting for clouds to clear, I did take a 300 s shot of the Crescent Nebula through the filter, and that was not enough. Clouds rolled in after only about an hour, so this session was cut off prematurely, although I did get a few more subs through "cheater holes." Already I can tell I captured a lot more contrast in M8 than I got unfiltered. It will be fun learning how to process the H-α data. The next step is to put this with my RGB data.
Date: 2 Aug 2014
Subject: M8, Lagoon Nebula
Scope: AT8IN+Antares 0.5x focal reducer
Filter: Baader H-α 7 nm
Mount: CG-5 (Synta motors, PicGoto Simplificado)
Guiding: 9x50 Finder/Guider + DSI Ic + PHD 2.3.0 (Win 7 ASCOM)
Camera: DSI IIc chiller at 2.50 A, 20 °C
Acquisition: Nebulosity 3.2.0, no dither
Exposure: 24x300 s
Stacking: Neb 3, bad pixel map, bias included, extract R, normalize, square B&W, trans+rot align, 1.5 SD stack.
Processing: StarTools 1.3.5.279 Crop; Auto Develop; HDR
ptimize; Deconvolute 2.5 pix; Life:Moderate; Track RNC 0.74%. CS6 Astronomy Tools double the pixels; H-α false color; Astro Frame.
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