Review

ZWO294MCP Astrophotography: Andromeda Galaxy 2024 Image

  • Updated December 19, 2025
  • Hannah Ruf
  • 16 comments

This image of the Andromeda Galaxy (M31) is a reprocessed version from 2024, captured using a SharpStar61 telescope paired with a ZWO294MCP camera and an Optolong LP filter. The setup was mounted on a Celestron CGEM mount, with guiding handled by a SvBony 240mm guide scope and a ZWO174MM Mini guide camera, all controlled via a ZWO ASiair. Data acquisition totaled two hours, consisting of 30″, 60″, and 120″ sub-exposures taken from a Bortle 3 dark sky site. Calibration included 40 darks, 40 flats, and 40 dark flats, with stacking performed in APP. The processing workflow in PixInsight involved STF, Dynamic Crop, DBE, Color Calibration, Background Neutralization, BlurXTerminator, Histogram Transformation, StarXTerminator, GAME mask, further Color Calibration, Curves Transformation, SCNR, another Histogram Transformation, Unsharp Mask, Pixelmath, and finally, adding the stars back in.

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16 Comments

  1. Seeing that you managed to capture this much detail from a Bortle 3 site with just two hours of total integration is really inspiring. It makes me reconsider my own plans from my suburban backyard; I might need to prioritize a trip to a darker sky. The detailed processing workflow, especially using BlurXTerminator and StarXTerminator before working on the galaxy, is a technique I want to try on my own M31 data. What was the most challenging part of balancing the galaxy’s core details with the faint outer regions?

    1. Thanks for your kind words—it’s great to hear that the Bortle 3 results and the processing steps are inspiring you to plan a dark-sky trip! Balancing that core and the faint halo was indeed the trickiest part; I used a GAME mask after separating the stars to carefully apply curves, boosting the outer arms while protecting the bright core from blowing out. If you try this on your data, I’d love to hear how it goes or see your result!

  2. Seeing that you captured this from a Bortle 3 site with just two hours of integration is really inspiring; it shows what’s possible with a dark sky and a solid processing workflow. I’ve been struggling with my own M31 data from a Bortle 5 zone, and your step using BlurXTerminator and GAME masks gives me a new approach to try for bringing out more detail in the dust lanes. What was the most challenging part of balancing the star removal and recombination with Pixelmath for you?

    1. Thanks for the kind words—it’s true that a dark sky site like Bortle 3 really helps maximize the signal from those faint dust lanes. The trickiest part of the star removal and recombination was definitely preserving the natural gradients in the galaxy’s core while still getting a clean starless layer for adjustments; I found that tweaking the StarXTerminator starmask growth setting before Pixelmath was key. If you’re experimenting with this on your Bortle 5 data, try a very gentle touch with the Curves on the starless layer to avoid an artificial look—I’d love to hear how it turns out for you.

  3. Seeing that you captured this from a Bortle 3 site really makes me appreciate the dark sky advantage; my own attempts from a Bortle 5 zone always struggle with that faint outer dust. Your detailed PixInsight workflow, especially the iterative use of Color Calibration and masks, gives me a few new ideas to try on my own M31 data from last season. What was the most challenging part of balancing the core detail with the faint outer arms?

    1. Thanks for the kind words, and I completely understand the challenge of pulling out that faint dust from a Bortle 5 sky—it’s a real fight against the gradient! The toughest part was definitely using a carefully crafted GAME mask to protect the bright core while applying curves and color saturation to the faint arms, so I didn’t blow out the galaxy’s center. If you’re revisiting your own data, try creating a very aggressive range mask for the core and applying your arm enhancements only to the inverted mask. I’d love to hear how your reprocessing goes with those new ideas.

  4. Seeing that you captured this from a Bortle 3 site makes me envious; my own attempts from a Bortle 5 zone always struggle with that faint outer dust. Your detailed PixInsight workflow, especially the iterative use of Color Calibration and masks, gives me a few new ideas to try on my own M31 data from last fall. What was the most challenging part of balancing the core detail with the faint outer arms?

    1. I completely understand the challenge of pulling out that faint outer dust from a Bortle 5 sky—it’s a real test of processing! The toughest part was using a carefully stretched GAME mask to protect the bright core while applying curves and color adjustments to boost the faint arms without clipping the galaxy’s center. If you’re reprocessing your fall data, try creating a very gentle luminance mask from your stretched image to isolate the outer arms for selective enhancement. I’d love to hear if that approach helps with your data.

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