5400 x 3551 px | 45,7 x 30,1 cm | 18 x 11,8 inches | 300dpi
Data acquisizione:
22 gennaio 2015
Altre informazioni:
The Orion Nebula, M42 and M43, with surrounding associated nebula and star clusters, such as the Running Man Nebula above (NGC 1975) and blue star cluster above it, NGC 1981. This is one of the most often photographed but most challenging dee-sky objects to shoot, because of its huge range in brightess from the bright core to the outlying wisps of dim red nebulosity. Capturing it all in one frame requires a form of “high-dynamic-range” techniques: shooting several different exposures and manually stacking and masking them in Photoshop. I shot and processed this image for use as a demonstration and tutorial image for my Photoshop for Astronomy Workshops. This demonstrates the methods and result of masking several different exposures to retain details in the bright core while also bringing out the faintest outlying bits of nebulosity, compressing the dynamic range tremendously. All processing was done with Adobe Camera Raw and Photoshop CC 2014. Total processing time from Raw to final was about 3 hours. The image is made of: - 10 x 6 minute exposures, Median combined in a registered stack, at ISO 1250. The median stacking reduced, but did not completely eliminate, the satellite trails from geosatatonary satellites that were in almost every frame. - 5 x 1.5 minute exposures at ISO 1250 for the mid-level brightness areas, blended using Darken mode - 5 x 30 second exposures at ISO 800 for the bright core, blended using Darken mode - 5 x 30 second exposures at ISO 400 for the brightest part of the central core around the Trapezium stars, blended using Darken mode Shorter exposure layers were stacked and masked using a luminance mask: created by Command Clicking on the RGB Channel to select just the highlights of that exposure then using that selection to create a mask to reveal the core area and hide the rest. Additional top-level layers were added for enhancing detail overall: - Luminosity layer created from the Red channel, and blended using Luninosity blend
