Messier 100 (also known as NGC 4321) is a grand design intermediate spiral galaxy located within the southern part of constellation Coma Berenices. It is one of the brightest and largest galaxies in the Virgo Cluster, located approximately 55 million light-years distant from Earth and has a diameter of 107,000 light years, roughly 60% the size of the Milky Way.
NGC 4323 and NGC 4328 are satellite galaxies of M100; the former is connected with it by a bridge of luminous matter. Also in this image is NGC 4322
Data captured over 6 nights between 19th January & 30th March, 2020.
52x 2 minute exposures with Blue filter (Binned 2x2).
52x 2 minute exposures with Green filter (Binned 2x2).
49x 2 minute exposures with Red filter (Binned 2x2).
335x 3 minute exposures with Luminance filter.
Total Exposure = 21.85 hours.
Skywatcher Quattro 200 CF
Atik 460EX Mono
This image was processed in Pixinsight & Lightroom.
Calibration and Stacking in Pixinsight using Batch PreProcessing.
Dynamic Crop - To remove black edges & integration artifacts. (Each Channel)
Automatic Background Extraction - To remove gradients. (RGB Channels)
Dynamic Background Extraction - To remove gradients. (Lum Channel)
Linear Fit - To match brightness of RGB channels (RGB Channels Separately)
Channel Combination - To combine RGB channels.
Photometric Colour Calibration - To calibrate colours.
SCNR - To remove green cast.
Deconvolution - To bring out some fine detail & tighten stars, 100 iterations. (Luminance only)
Multiscale Linear Transform - Noise reduction. (Luminace & RGB separately)
Histogram Transformation - To stretch the RGB & Lum. (Using statistics process to keep background levels evenly)
LRGB Combination - To blend my luminance image with my RGB image.
TVGDenoise - To reduce noise, with Rangemask to protect Galaxy.
Histogram Transformation - To clip blacks slightly.
HDR Multiscale Transform - To recover detail in the galaxy core & inner arms, with star mask in place.
UnsharpMask - To sharpen with inverted nebula mask in place to exclude stars & background.
Local Histogram Equalisation - To sharpen / add contrast, with previous mask in place.
Dynamic Crop - To crop away most of the background.
Curves Transformation - To desaturate background, with rangemask to protect galaxy & stars.
Curves Transformation - To boost galaxy saturation, with inverted nebula mask in place.
Curves Transformation - To boost contrast, with nebula mask in place.
TVGDenoise - To reduce Deconvolution artifacts on galaxy edge, with range mask in place.
Export as JPEG and import into Lightroom.
Increase Contrast (+15)
Reduce Shadows (-25)
Reduce Blacks (-15)
Boost Saturation (+25)
Boost Magenta Saturation (+50)
Export final JPEG for upload.