Comparison

ND Slow Shutter vs ksAstroLens

Price, ratings, monetisation and update history for both apps, side by side β€” with what reviewers say about each.

Head to head
About

ND Slow Shutter

Features
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Master Long Exposure Photography with Ease ND Slow Shutter helps you calculate the perfect shutter speed when using Neutral Density (ND) filtersβ€”so you can focus on creativity, not math. Key Features β€’ Instant Calculations β€” Enter your base exposure and ND filter strength (ND1–ND20) to get precise results in seconds β€’ Built-in Timer β€” Stay in control during long exposures with an optional countdown timer β€’ Simple & Intuitive β€” Clean, fast interface designed for photographers of all levels β€’ Apple Watch Support β€” Control your exposures and timer directly from your wrist (Premium) Why ND Slow Shutter? β€’ Accurate Results β€” Reliable calculations you can trust in the field β€’ Faster Workflow β€” No guesswork, no manual conversions β€’ Shoot with Confidence β€” Focus on composition while the app handles the math Whether you’re capturing silky waterfalls, smooth seascapes, or motion blur, ND Slow Shutter gives you the precision and control you need. Download now and elevate your long exposure photography.

About

ksAstroLens

Features
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AstroLens turns your iPhone into a fully manual astrophotography camera, designed for afocal shooting through the Vaonis Hestia smartphone telescope. THE PROBLEM IT SOLVES When your iPhone sits on a telescope eyepiece, the native Camera app silently switches from the telephoto lens to the wide lens with a digital crop, because autofocus cannot converge through the optics. AstroLens locks the physical lens of your choice (the optical telephoto by default) and never switches away from it. Zoom stays at 1.0Γ—: pure optical magnification, no digital crop. FULLY MANUAL, FULLY DETERMINISTIC β€’ Manual focus slider with focus peaking and a magnifying loupe β€’ One-tap mirror flip to correct the telescope's inverted image (preview and captures) β€’ Manual shutter speed and ISO, bounded by the real sensor limits β€’ Locked white balance for consistent colors across shots β€’ Live histogram to nail the exposure MADE FOR THE NIGHT β€’ Sun, Moon, Landscape and Deep Sky modes with sensible starting presets β€’ Mandatory solar-filter confirmation before Sun mode β€’ Crosshair, telescope-field circle and composition grid overlays β€’ Red-on-black night theme to preserve your dark adaptation β€’ 2-second self-timer and volume-button shutter to avoid vibrations β€’ Apple Watch remote shutter: trigger from your wrist without touching the iPhone, with the mode, shutter speed and ISO on your watch β€’ Burst capture for stacking deep-sky images β€’ Apple ProRAW support (on compatible iPhones) plus HEIF β€’ Captures saved to a dedicated β€œHestia” album FIND YOUR TARGET β€’ Sun/Moon alignment assistant: on-screen arrow plus turn and tilt guidance, computed from your location and the phone's motion sensors, fully offline β€’ Works uncalibrated right away: the compass gets you close on its own; then center the target once in the eyepiece view and tap Calibrate for degree-level pointing β€’ Adapter geometry is configurable (Hestia's mirrored optics by default) AstroLens works on any recent iPhone: without a telephoto lens it locks the main wide lens instead, still with zero automatic switching. Vaonis and Hestia are trademarks of their respective owner. AstroLens is an independent app, not affiliated with, endorsed by, or sponsored by Vaonis.

Screenshots

ND Slow Shutter4 screens
ksAstroLens4 screens

Verdict

The call

The clearest difference is price: ND Slow Shutter at Free against ksAstroLens's $0.99. ksAstroLens's advantage is in-app purchases (none vs 1) and ads (none vs shown). On device support and iOS requirement there is nothing between them.

Scored on Price Β· Rating Β· Positive reviews Β· Number of ratings Β· Update frequency Β· Ads Β· In-app purchases Β· Monetization Β· Best chart rank Β· Devices Β· Requires iOS

CostPrice Β· In-app purchases Β· Ads Β· Monetization

ND Slow Shutter is free to download; ksAstroLens costs $0.99 up front. ND Slow Shutter sells 1 one-off in-app purchase. ksAstroLens asks for nothing beyond the download.

UpkeepUpdate frequency

ND Slow Shutter ships an update every 3 weeks, ksAstroLens every 3 days. The most recent releases landed on October 28, 2026 and October 29, 2026 respectively.

Scorecard4 real differences Β· 2 level
ND Slow Shutter versus ksAstroLens: the parameters behind the verdict, then further details
ParameterND Slow ShutterksAstroLens
PriceFree β€” better$0.99
Update frequencyEvery 3 weeksEvery 3 days β€” better
AdsYesNo β€” better
In-app purchasesYesNo β€” better
DevicesiPhone, iPad, Apple Watch β€” betteriPhone, Apple Watch
Requires iOS17.617.0 β€” better
Further details β€” not scored
Size22 MB3 MB
Age rating4+4+
DeveloperFrancesco FoianesiChristophe Calmejane

In-app purchases

1 purchases

ND Slow Shutter

One-time1
  • Premium Version$2.99
None

ksAstroLens

No in-app purchases

Questions

Is ND Slow Shutter free?
ND Slow Shutter is free to download, with in-app purchases available.
Is ksAstroLens free?
ksAstroLens costs $0.99, with no in-app purchases.
Do ND Slow Shutter or ksAstroLens have ads?
ND Slow Shutter shows ads; ksAstroLens does not.
Which is updated more often, ND Slow Shutter or ksAstroLens?
ND Slow Shutter ships an update every 3 weeks, and ksAstroLens every 3 days. Most recently, ND Slow Shutter was updated on October 28, 2026 and ksAstroLens on October 29, 2026.

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