Astro Stacker vs AI CometStack
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Astro Stacker
Transform your smartphone into a powerful astrophotography tool. This app uses advanced algorithms to combine multiple night sky photos, reducing noise and revealing hidden celestial details for professional-quality results.
- Advanced stacking algorithms (Average, Median, Maximum, Minimum)
- Intelligent and manual image alignment
- Real-time processing and progress tracking
- On-device processing, no cloud upload
- Export high-resolution stacked images
- Detailed processing insights and logs
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Stack your night-sky photos into one cleaner, more detailed image, right on your iPhone or iPad. Astrophotography stacking combines many exposures of the same sky. Astro Stacker finds the stars in every frame, lines them up and combines them, so random noise falls away and faint stars, the Milky Way and deep-sky targets come through. HOW IT WORKS 1. Take several separate photos of the same patch of sky from a tripod or stable surface. 2. Import them from Photos or Files into a Deep Sky Studio project. 3. Pick a stack mode and tap Stack. 4. Finish the result with Auto Stretch, styles and colour tools, then save or export. THREE SIMPLE STACK MODES - Quick: averages every frame for a fast first look. - Quality (default): rejects outliers such as plane and satellite trails, and leaves out the weakest frames. - Max Detail: the slowest and most selective mode, with finer alignment. AUTOMATIC STAR ALIGNMENT Stars are detected and matched in every frame, with sub-pixel alignment and a quality check for each frame. Stacking needs clear stars in your photos to line them up. CALIBRATION FRAMES (PRO) Add darks, flats, dark-flats and bias frames to correct hot pixels, thermal noise, vignetting and dust. Astro Stacker sorts frames by file name and exposure, so files named "dark" or "flat" are picked up for you. FINISH IN THE SAME APP - Auto Stretch to bring faint signal into view - Gradient removal for light pollution and uneven skies - Local contrast, vibrance, levels and per-channel colour balance - Styles: Natural, Nebula Pop, Cosmic Drama and Scientific, each with a strength slider - Before-and-after comparison - Quick Enhance for a single photo you've already taken FILES IN AND OUT - Import: photos from your library on Free; camera RAW, Apple ProRAW and FITS on Pro - Export: JPG, PNG, TIFF and FITS, with 16-bit export on Pro ON-DEVICE Stacking and editing run on your iPhone or iPad. You don't need a computer, and your source frames are not uploaded to stack them. An optional account backs up finished results. FREE AND PRO Free: up to 10 light frames per stack, 3 stacks every 7 days and 3 saved results. Pro: unlimited frames and stacks, RAW, ProRAW and FITS import, calibration frames, 16-bit export and unlimited history. Choose monthly, annual or a one-time lifetime purchase. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the period, and you can manage them in your App Store account settings. GOOD TO KNOW - Moon, planet and solar stacking (Planet Lab) is coming soon. Today's stacking needs stars to align on. - Colour FITS files from one-shot-colour cameras are not debayered yet. - Star-trail stacking isn't supported, because every stack is aligned on the stars. Guides to capturing and stacking: https://astrostacker.co/guides Privacy Policy: https://astrostacker.co/privacy Terms of Use: https://astrostacker.co/terms Apple Standard EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
AI CometStack
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AI CometStack is a breakthrough comet alignment app designed specifically for mobile astrophotography workflows. Overcome the long-standing tradeoff of comet movement during long imaging sessions. Traditionally, you had to choose between sharp stars (streaked comet) or a sharp comet (trailed stars). AI CometStack solves this by eliminating complex desktop compositing and advanced scripting. Core Features Motion-Aware Stacking: Aligns the comet nucleus across time while preserving star geometry. Two-Path Automation: Integrates stars and comets separately, then blends them on-device. Batch Processing: Handles full-night capture sets with uniform parameters. Pro Format Support: Works natively with FITS, RAW, TIFF, PNG, and JPEG files. Mobile-First Flow: Real-time previews and guided steps built for iOS deep-sky sessions. Simple Workflow Import your exposure frames (or use the included sample files). Let the app automatically track and model comet motion. Validate and adjust the seamless background blend in real time. Export gallery-grade, press-ready images instantly from the field. Support & Feedback Questions, feedback, or need help? Contact us directly at ustransit74@gmail.com Privacy policy and term of use (EULA) is at https://deepskycolor.blogspot.com/2018/12/privacy-policy-for-deep-sky-color-app.html
Screenshots
Verdict
Astro Stacker and AI CometStack are too close to call on the numbers: across 5 compared parameters — price, ads, in-app purchases and device support among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Astro Stacker sells 3 in-app purchases, starting at $12.99 per month and AI CometStack sells 1 in-app purchase, starting at $9.99 per year. Whichever you choose, the download price is not the number that matters.
| Parameter | Astro Stacker | AI CometStack |
|---|---|---|
| Price | Free | Free |
| Rating | 1.0 (6 ratings) — better | — |
| Positive reviews | 0.0% of reviews | — |
| Number of ratings | 6 — better | — |
| Update frequency | Fortnightly | — |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free | — |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 17.0 | 17.0 |
| Further details — not scored | ||
| Size | 17 MB | 105 MB |
| Age rating | 4+ | 4+ |
| Developer | Ahmed Al-Mahmud | yong chong loh |
In-app purchases
Astro Stacker
- AstroStacker app$12.991 Month
- AstroStacker app$99.991 Year
- AstroStacker app$219.00
AI CometStack
- Yearly Subscription$9.991 Year
Questions
Is Astro Stacker free?
Is AI CometStack free?
Do Astro Stacker or AI CometStack have ads?
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