# ND Filter Calc vs ND Slow Shutter

The clearest difference is in-app purchases: ND Filter Calc at none against ND Slow Shutter's 1. ND Filter Calc also leads on ads (none vs shown) and update cadence (every 6 days vs every 3 weeks). On price and device support there is nothing between them.

Both are free to download. ND Slow Shutter sells 1 one-off in-app purchase. ND Filter Calc asks for nothing beyond the download.

ND Filter Calc ships an update every 6 days, ND Slow Shutter every 3 weeks. The most recent releases landed on September 30, 2026 and September 29, 2026 respectively.

## The numbers

| Metric | ND Filter Calc | ND Slow Shutter |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | **Every 6 days** | Every 3 weeks |
| Monetization | Free | — |
| Size | 47 MB | 22 MB |
| Requires iOS | **15.0** | 17.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [Jerry Watson](https://appshunter.io/developer/1647846813) | [Francesco Foianesi](https://appshunter.io/developer/1817962841) |

## What reviewers say

### ND Filter Calc

[App page](https://appshunter.io/ios/app/nd-filter-calc/id6449380764)

This tool helps photographers calculate neutral density filter effects on their camera's exposure. It includes a countdown timer for long exposures, simplifying the process of achieving desired results.

**Highlights:** Neutral density filter calculation, Exposure compensation, Long exposure timer, Countdown for shutter speeds > 3 seconds, Simple interface

**In-app purchases:** none


### ND Slow Shutter

[App page](https://appshunter.io/ios/app/nd-slow-shutter/id6747008686)

**Features:** Family Sharing, Apple Watch app

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Version | $2.99 | one-time |


## Frequently asked questions

### Is ND Filter Calc free?

ND Filter Calc is free to download, with no in-app purchases.

### Is ND Slow Shutter free?

ND Slow Shutter is free to download, with in-app purchases available.

### Do ND Filter Calc or ND Slow Shutter have ads?

ND Slow Shutter shows ads; ND Filter Calc does not.

### Which is updated more often, ND Filter Calc or ND Slow Shutter?

ND Filter Calc ships an update every 6 days, and ND Slow Shutter every 3 weeks. Most recently, ND Filter Calc was updated on September 30, 2026 and ND Slow Shutter on September 29, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*