NE-FL-AstroFor a while now, I’ve wanted to do a deep image on Andromeda’s core with an emphasis on the hydrogen alpha. For the last month or so, I’ve been pointing my telescope at Andromeda to do just that.The stacking was done in Pixinsight along with some of the basic editing and continuum subtraction. To blend it all together, I moved over to Photoshop. I could not simply screen the Ha over the LRGB image as the core is too bright to show any detail. Instead, I screened the Ha for the outer bands and large bright nebulae. For the core, I had to use additional layers with a mask to exclude the outer regions. For layer types, I used luminosity with reduced fill/opacity and additional screen layers. It took a fair amount of blending with masks to get the level of control I needed. As far as noise reduction, I found it best to do the continuum subtraction on images with zero noise reduction and then run NoiseXterminator after. I also created a super luminance frame for the luminance layer, maximizing detail and SNR.
