Located on the back of the back of Leo's Mane lies 4 galaxies known as Leo's Quartet: each galaxy being unique in appearance. This image consists of photos taken across 3 nights this week. Despite the total amount of integration time this image represents nights of fighting to identify the source of comet-shaped stars in my images. It seemed that targets lower on the horizon (50-60* altitude) would have bad abberations on each star: all pointing the same direction: but when pointing higher up near zenith they would mostly go away. I fought diligently to check collimation, pinched optics from perhaps my mirror clips being too tight (twice), but it seems that perhaps tube currents may end up being the major culprit as it seems it's better to let the scope cool down without the cap on than to set it out to cool for a few hours with the cap on. Thanks to many in the /r/astrophotography discord for helping me fight through this issue. I suspect as a result that the focus seems slightly off as focus was done when the abberations were still present. I highly welcome and encourage feedback and any tips to improve.

**Equipment:**

* Orion 8in f4.9 1000mm / Flocked / Mask on Turned down edge on primary

* Guiding with ZWO 60mm f4.6 guidescope and asi178mm camera (first of the three nights)

* Guiding with ZWO Off Axis Guider asi178mm camera (the last two of the three nights)

* ASI071mc one-shot-color cam

* Hutech IDAS LPS D1 Filter

* Celestron CGEM Mount

**Acquisition:**

* Lights: 705x60s taken across nights in late March 2019 (11 hr 45 minutes total integration)

* Flats: Separate flats taken each night before imaging using evening sky and t-shirt (Thank you [NINA' Flats Wizard]((https://nighttime-imaging.eu/docs/documentation/tabs/flat-wizard/)) for being amazing!!!)

* Darks: 60x60s at -10C

* Bias: None

* Bortle Dark-Sky Scale: 4.00

* Pixel scale: 0.981 arcsec/pixel

* Orientation: 180* degrees

**Pre-Processing with PixInsight:**

* Calibrated and stacked using [LVA PreProcessing Steps](http://www.lightvortexastronomy.com/tutorial-pre-processing-calibrating-and-stacking-images-in-pixinsight.html)

* Integrated best 705 of 747 frames selected using a combination of Blink Subframe Selector: removing stars with bad trails and significant clouds

* Weighting:

```

5*((Stars - StarsMin) / (StarsMax - StarsMin))

+ 15*(1-(FWHM - FWHMMin) / (FWHMMax - FWHMMin))

+ 45*(1-(Eccentricity - EccentricityMin) / (EccentricityMax - EccentricityMin))

+ 20*((SNRWeight - SNRWeightMin) / (SNRWeightMax - SNRWeightMin))

+ 30

```

* No Local normalization

* CFA drizzled

* Crop with Dynamic Crop

* Dynamic Background Extraction

* Background Neutralization

* Photometric Color Calibration

* RGB Working space to 1,1,1

**Extract synthetic L for Deconvolution**

* Deconvolution with a Dynamic PSF L |> select 15 samples from middle of image |> Export PSF

* Starmask for local support 0.3

* Global Dark: 0.0080

* Global Bright: 0.0005

* 3 layers of Poisson wavelet regularization

**Extract synthetic L for Noise Reduction**

* TGV Noise reduction Using a low contrast mask

* MMT Noise reduction using 8 layers and a very protective luminance mask

**RGB workflow:**

* Small Scale noise reduction using TGV Denoise

* Chrominance Noise reduction using MMT

* Color Saturation

* ArcSin Stretch

* Remove faint spec-like noise in the image with ACDNR

**Combining Sharpened L, NR L and Stretching Luminance**

* Pixel Math with luminance-based mask to apply Deconvolution image only to the non-background areas of the Noise Reduced L

* Stretch with Masked Stretch

* Sharpen with Multiscale Median Transform using a luminance mask

** LRGB Combination **

* Shrink medium size stars with contours mask and morphological transformation

* Additional round of DBE

* Subtle Unsharp Mask with a luminance mask

* Cleanup over-saturated stars with a little masked convolution

* Save as JPEG