This is presented in a large (1920 pixel wide) image to show detail. The Fox Fur, Christmas Tree, and Cone Nebula area and the Rosette Nebula are represented. Trumpler 5 is the yellow-ish cluster below the cone area, and below and a bit to the right of that is IC 2169. I used some of my regular processing techniques on this, but this image represents my first foray into PixInsight (PI). I used several PI tools, but the compelling feature that drove me to make the jump was the Dynamic Background Extraction tool (DBE). That was required to address significant green gradients that plagued this image.
The above is composed of 40 * 5 minute frames (3 and 1/3 hour total), as noted with the Nikon D810A camera and Zeiss 135mm lens. The lens is f2.0 and I stopped it down to f2.8 for all imaging on this trip. Image reduction with darks & flats in DSS, then processed in PixInsight & Photoshop CS6. The weather was cold for Texas and I recorded 43 degrees as the typical temperature during the imaging session. I used 77 darks captured during 40 to 51 degree temps (captured on another cold but cloudy night). I went with t-shirt flats, 72 of them, auto-exposed at -EV. It looks like forcing your flats to be dim is critical to getting decent image reduction with the camera; perhaps it is non-linear in the normal exposure range...
After the gradient, the stars where a real challenge here. Registar counted 492,302 stars in the original and very mildly cropped image! I worked with star reduction in PixInsight and in Phototoshop, though I'm not entirely happy with the results.
This page has information and pictures on the equipment used during the trip. See this on my Cone Nebula and Christmas Tree Cluster Page, along with other images of the area. There's a dedicated Rosette Nebula page here, also.
I caught this one during the last night of the trip, it is almost exactly 1 day past new.
Check my main M42 page for details.
Horsehead Nebula January 2017 (Click Here!)
Images Copyright © by Dick Locke. All Rights Reserved.
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Update Feb 2017