M45, the Pleiades star cluster, in a series of exposures to test stacking images with HDR techniques. I shot the cluster in a series of 1, 2, 4, and 8 minute exposures, four of each exposure, all using the Nikon D750 and 92mm TMB refractor. A set of 1,2,4, and 8 minute exposures was stacked in Camera Raw using its HDR mode to create a new merged DNG file. I did this for four sets of 1 to 8 minute exposures, then processed each of the HDR stacks with Shadows and Highlights in ACR to bring out faint detail but retain detail in the bright core. Each of the 4 HDR stacks was then mean combined stacked in Photoshop and processed with Curves, S&H, B&C etc. So in total this is a stack of 16 images, 4 each x 1, 2, 4, and 8 minutes. Diffraction spikes added in Photoshop with Astronomy Tools actions.
M45 Pleiades in Taurus - with Canon 20Da and 135mm Canon L-series telephoto at f/2.8 for stack of 4 x 6 minute exposures at ISO 400 (2 images c-added, 2 images averaged) - taken from home under ideal conditions Sept 30 2008. Field of view across short dimension of frame equals that of typical binoculars. Faint nebula above M45 is IC 353.
M45 with 200mm lens at f/4 for stack of two 4-minute exposures at ISO400. Canon 20Da camera. October 21, 2006
