SaratogaSkies Jim Solomon's Astropics

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December: Test shots with new scopes/mounts

Dec 21: TMB 80/480 Arrives!

Dec 3: AP1200 Arrives!

Nov 30: TMB 152/1200 Arrives!

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Outer Planets (Jupiter Uranus Neptune)

Image Details:

Camera: SBIG ST-2000XM
Mount: Astro-Physics 1200GTO
Scope: AP Starfire 160EDF APO Refractor
Configuration: Negative Projection (Barlowed)
Additional Optics: TeleVue 5x PowerMate
Filter: Astrodon RGB I-Series Filters
Effective Focal Length: 6185mm
Effective Focal Ratio: f/38.7
Exposure: Jupiter: 50 × 0.1s; Uranus & Neptune: 100 × 1s {R,G,B}
Total Exposure: 0hrs, 3min
Date: 8/26/2008 9:45 PM PDT
Location: Saratoga, CA, USA
Acquisition: CCDSoft
Focus: FocusMax
Dithering: None
Guiding: None

Processing:

  • IRIS: Registration, Wavelets, White balance, G2V calibration
  • JimP: Dark subtraction, Flat field, Kappa-Sigma Stacking
  • Photoshop: Compositing, JPG conversion

Image Description:

This is my first attempt at imaging planets with an astronomical CCD camera, as opposed to with a webcam or DSLR. Uranus and Neptune are particularly difficult targets, given their tiny apparent sizes (3.7” and 2.3”, respectively). I did a G2V star color calibration, corrected for atmospheric extinction, in order to get as accurate a color balance on Uranus and Neptune as possible. On a decent monitor, the difference in color between those two should be fairly obvious. All in all, given the wrong tool for the job — a CCD with a painfully slow frame rate — and the awful seeing, I'm pretty pleased with the results. Jupiter was done as a “control” group to make sure I didn't get carried away with wavelet processing. In fact, I used the same wavelet coefficients on all of the individual images. The image is a composite pasted together in Photoshop of the highly cropped, but nonetheless full resolution images. Hover the mouse over the image to see the labels, although such should not be necessary given the highly educated nature of the visitors to my web site! <smile> North is up.

 
IC 410 (Tadpole Nebula)
SaratogaSkies Jim Solomon's Astropics

Search

Latest news

December: Test shots with new scopes/mounts

Dec 21: TMB 80/480 Arrives!

Dec 3: AP1200 Arrives!

Nov 30: TMB 152/1200 Arrives!

Links:

IC 410 (Tadpole Nebula)

Mouse-over to see annotations. (Requires Javascript) Click to see high-res version.

Image Details:

Camera: SBIG ST-2000XM
Mount: Astro-Physics 1200GTO
Scope: TMB 152/1200 APO Refractor
Configuration: Prime Focus
Additional Optics: n/a (Prime)
Filter: Astrodon SII, Hα, OIII 6nm Filters
Effective Focal Length: 1200mm
Effective Focal Ratio: f/7.9
Exposure: {3 SII, 3 Hα, 2 OIII} × 32min @ -30°C
Total Exposure: 4hrs, 16min
Date: 2/4/2008 8:41 PM PST (Start)
Location: Saratoga, CA, USA
Acquisition: CCD Commander
Focus: FocusMax
Dithering: CCD Commander
Guiding: Self Guided

Processing:

  • IRIS: Registration
  • JimP: Dark subtraction, Flat field, Kappa-Sigma Stacking, White balance, ASINH stretching
  • Photoshop: Neil's Trick, JPG conversion
  • Neat Image: Noise reduction

Image Description:

This is IC 410, aka, the “Tadpole Nebula”, an emission nebula and open cluster (NGC 1893) in the constellation of Auriga. This is my first attempt at automation with CCD Commander. I made a bunch of newbie mistakes, but eventually got it up and running.

Mousing off the image reveals a “Hubble Palette” narrowband image, with R:G:B = SII:Hα:OIII. Mouse-over the image to see a pseudo-“True Color” image, in which those narrowband emission lines are mapped to their approximate color as seen by human vision. Specifically, the red SII and Hα wavelengths are mapped to red, and the aqua (blue-green) OIII wavelength is mapped to both green and blue. Also, a smidge of Hα is added into blue to simulate the Hβ wavelength.

I'm still fighting some star trailing/smearing in my images with the new camera/scope/mount, as yet undiagnosed. Thanks much to Neil Flemming's Trick, I was able to reduce that smearing. A higher resolution image is also available. North is up.