The Heart Nebula (aka IC 1805) at right, and the Soul Nebula (aka IC 1848) at left, in Cassiopeia. The round nebula at top right is NGC 896. The star cluster at right embedded in the Heart Nebula is NGC 1027. Shot from home in Alberta on November 21, 2019. This is a stack of 16 images, half of the set shot through a light pollution reduction filter to suppress sky background and enhance the colours of the nebulas, particularly in the red end of the spectrum from H-alpha emission. The eight filtered shots are all 8-minute exposures with the Canon EOS Ra mirrorless camera at ISO 1600, and through the Borg 77mm f/4 astrographic refractor at f/4 with an IDAS LPSv3 filter in place. The 8 unfiltered shots are all 8-minute exposures as well but at ISO 800 (with no filter the images require less exposure) and with the same camera and scope but without the IDAS filter for a set of “natural light” images. Blending the two versions provides the benefit of the enhanced nebulosity of the filter but the better colour balance of the unfiltered shots. The EOS Ra camera features a factory-modified IR block filter that transmits a higher level of the red H-alpha visible light, making such a photo possible. The additional IDAS filter does bring out the fainter parts of the nebulas but tends to make the nebulas quite “in-your-face” red, rather than present a more balanced look with magenta and blues adding to the colour. This was shot from a fairly dark rural site, so the IDAS filter wasn’t essential for urban sky glow suppression but for nebula enhancement. All images aligned and stacked in Photoshop 2020. We don’t need no Deep Sky Stacker.
The Heart Nebula (IC 1805) in Cassiopeia with the star clusters Melotte 15 (at centre) and NGC 1027 (at left), with the nebula NGC 896 at upper right. I shot this October 6, 2016 from home with an Explore Scientific FCD102 apo refractor at f/7. This is a stack of 8 x 4.5-minute exposures at ISO 1600 with the filter-modified Canon 5D MkII. Stellar diffraction spikes added with Astronomy Tools Photoshop actions.
The Horsehead Nebula, B33, below the Belt of Orion and the star Alnitak, along with the bright Flame Nebula, NGC 2024, to the left of Alnitak. Many other bright reflection nebulas populate the field, such as NGC 2023 just left of the Horsehead itself. The quintuple star system Sigma Orionis is right of the Horsehead. The dark Horsehead is set against the bright streak of the emission nebula IC 434. This is a stack of 10 x 4 minute exposures with the Celestron Rowe-Ackerman Schmidt Astrograph, a 620mm focal length f/2.2 astrograph in hand for review, and using the filter-modified Canon 5D MkII at ISO 400. Autoguided on the Mach 1 mount. Taken from New Mexico, Nov 28, 2014.
