Orion Rising Over Courthouse Butte

February 12, 2016 Leave a comment

Sedona, Arizona has the clearest, darkest skies I may ever see (anywhere near civilization at least).  Who knew there was a winter Milky Way visible too?!  Not this suburbanite.

I got one clear night to test out both my new Samyang 14mm lens and the iOptron SkyTracker.  While this image is not the best example of the SkyTracker’s abilities, since I misaligned it, the foreground framing was better than the other shots I took.  So this is the one I chose to process first.

Red Rocks combined FINAL for blog

Image data:

  • Exposures:  sky:  20×30 seconds, foreground: 1×30 seconds
  • Telescope: Samyang 14mm f/2.8 lens at f/4
  • Cameras: Canon 6D (modified)
  • Mount: iOptron SkyTracker
  • Guiding: none
  • Conditions:  excellent transparency, passing clouds
  • Processing: DeepSkyStacker -> PixInsight -> Photoshop
  • Date: Jan 29, 2016
Advertisements

Cocoon Nebula (IC5146) Widefield

January 24, 2016 1 comment

I used the snow day here in the northeast to get started on the backlog of raw data from the fall that I haven’t processed.  This is the Cocoon Nebula, with its dark nebula friend, Barnard 168.

Cocoon FINAL v2

I actually took a full night’s worth of H-alpha data, but decided to use only the RGB data here, as a slight misalignment of the telescope shooting the H-alpha would have required a different cropping of the image.

Image data:

  • Exposures:  15×10 min R, G; 18×10 min B (2×2 binning) – total exposure time:  8 hours
  • Telescope: William Optics Star71 (360mm f/5)
  • Cameras: SBIG ST-8300M
  • Mount: Takahashi EM200
  • Guiding: QHY 5L-II mono, guided using PHD2
  • Conditions:  good transparency, calm winds
  • Processing: DeepSkyStacker -> PixInsight -> Photoshop
  • Date: Sep 14 and 17, 2015

Evaluating the full-frame performance of the William Optics Star71

January 23, 2016 1 comment

I’m excited to start imaging with my new Canon EOS 6D.  Having a full-frame chip will allow some very widefield shots that would require mosaics with a 4/3 sensor, like the KAF-8300 cameras I use most of the time.  Since conditions were less than ideal, I used the first couple of nights out to run some tests.  First up is a test of the 6D with the Star71.

The obvious target:  M42.  Below is a very brief exposure (17 min total, in 15s subexposures).

M42 17 min

That is a very wide field.  5.8 x 3.8 degrees.  I didn’t even intend to include the Horsehead Nebula when I pointed the mount at M42, but the field is so wide, I accidentally captured most of it.

Are the stars sharp out to the corners?  Yes.  The image below is a crop of 100 pixel squares from each corner of the above image.  No star reduction was done in any of these images. The performance is really good.  A little distortion on the right side, but quite tolerable.

Corners

What about vignetting?  I estimate less than 10% light falloff between the center and the corners from the flat frame analysis below (the image is highly stretched to reveal vignetting).  Note that there is a dark band across the bottom.  This was consistent across my images, and I’m not sure of the source, but I suspect something to do with dcraw (this image was imported into PixInsight, which calls dcraw for conversion).  DeepSkyStacker seemed to have trouble with some of the 6D’s images too.

vignetting

The 6D and Star71 are a good pair, and it’s nice to have a DSLR again for simple one-shot color imaging, especially for wide fields.  Once I get some adapters, I look forward to running the same test with the Takahashi FSQ-106ED.

The Pleiades (M45)

January 10, 2016 Leave a comment

Somehow, I’ve never really captured an image of The Pleiades (M45). Such a bright target directly overhead, but I was mostly looking for narrowband objects instead, I suppose.

Pleiades final 8x10 crop

This image was processed entirely in PixInsight, except for the final rescaling and jpeg conversion.  I’m moving more in that direction. Frustrating and unforgiving it is, but powerful.  For such a bright object, the dust makes it more challenging to process than I’d expected.

Image data:

  • Exposures: 20×10 min L (1×1 binning), 8×10 min each R, G, B (2×2 binning) – total exposure time:  7h 20m
  • Telescopes: Two William Optics Star71s (360mm f/5)
  • Cameras: SBIG ST-8300M and QSI 583wsg
  • Mount: Takahashi EM200
  • Guiding: QHY 5L-II mono, guided using PHD2
  • Conditions:  fair transparency, calm winds
  • Processing: DeepSkyStacker -> PixInsight
  • Date: Jan 2, 2016

Comet Catalina (C/2013 US10)

January 3, 2016 Leave a comment

Comets are difficult objects to capture and process, but the good ones are worth the effort. Catalina sits in the pre-dawn skies right now.  I’ve gotten up at 4am two mornings in a row to get this shot.  Yesterday, I captured it with Arcturus in the same frame, but I underestimated the comet’s dimness, so the final image was fairly dim and noisy. This morning, I doubled the exposure time with better results.

Catalina LRBG 3

LRGB imaging is not ideal for comets: even with 2-minute exposures, there is shift between them.  DeepSkyStacker comet alignment mode is great, but the color channels don’t quite line up perfectly. Next time, I’ll use a DSLR.

Image data:

  • Exposures: 52×2 min L, 18×2 R, 16×2 G, 17×2 B
  • Telescopes: Two William Optics Star 71s (360mm f/5)
  • Cameras: SBIG ST-8300M and QSI 583wsg, 2×2 binned
  • Mount: Takahashi EM200
  • Guiding: QHY 5L-II mono, guided using PHD2
  • Conditions:  light wind, nearby moonlight
  • Processing: DeepSkyStacker -> PixInsight -> Photoshop
  • Date: Jan 3, 2016

The Astrophotography Sky Atlas

November 22, 2015 Leave a comment

TASA Cover 500px

The Astrophotography Sky Atlas is now available at Amazon!

I spent two years coding, researching, and writing this book with a simple goal:  to create a compact, reasonably-priced atlas designed for the imager. Over 2000 deep-sky objects are plotted in their correct size and shape, including many faint nebulae not shown in other atlases. Stars are shown down to 9th magnitude.  The entire sky is covered in 70 full-color charts.

A tabular index contains important details on each object, including a description, the best time of year to capture it, and the required field of view.

What’s shown:

  • 416 emission nebulae and supernova remnants, including the complete Sharpless (Sh2) and RCW catalogs.
  • 171 reflection nebulae, including the complete van den Bergh (vdB) catalog.
  • 146 planetary nebulae, including the complete Abell catalog
  • 52 dark nebulae and molecular clouds
  • 792 galaxies (larger than 3 arcminutes)
  • 38 galaxy groups from the Abell and Hickson catalogs
  • 108 globular clusters (larger than 5 arcminutes)
  • 309 open clusters (larger than 5 arcminutes)

Keeping a focus on what is important to imaging, sparse open clusters and galaxies smaller than 3 arcminutes (unless part of a group) were left off the maps.

With information on nearly every possible photographic object in the night sky, The Astrophotography Sky Atlas will help you choose your targets and plan your imaging.

Haumea

October 10, 2015 Leave a comment

I took these images back in June, but have been too busy working on the new book to post anything.  I have literally hundreds of hours of exposures waiting to be processed right now.

This is Haumea.  It’s not a pretty image, but I still think it’s cool that you can image Kuiper Belt objects from your backyard.  In fact, the collimation on my scope was WAY out of line (long story) when these were taken, and I was still able to capture Haumea with 8 minutes of exposure time on two nights (6/6 and 6/9).  This was also first light for my SBIG STL-1301E.

Haumea’s angular motion is only about 2.5 arcseconds over three nights.  I compared the images with Wolfram Alpha’s predictions for where Haumea would be, and they agree within a few arcseconds.  The differences are probably more due to my measurement error using Aladin than calculation errors:

  • June 6th:  predicted RA: 13h 58′ 46″, measured RA: 13h 58′ 41″
    • predicted Dec: +18d 02′ 17″, measured +18d 02′ 32″
  • June 9th:  predicted RA: 13h 58′ 38″, measured RA: 13h 58′ 32″
    • predicted Dec: +18d 01′ 38″, measured +18d 01′ 56″
Haumea June 6-9, 2015

Haumea June 6-9, 2015

  • Exposures: 8×1 and 10×1 minutes
  • Telescopes: AstroTech AT8RC (1600mm f/8)
  • Cameras: SBIG STL-1301E, 2×2 binned
  • Mount: Takahashi EM-200
  • Guiding: Orion Starshoot through 50mm finder, guided using PHD2
  • Processing: DeepSkyStacker -> Photoshop
  • Dates: Jun 6 2015 and Jun 9 2015
%d bloggers like this: