# Actinic: Exposure Calculator — Reciprocity Failure, Offline

> Reciprocity Failure, Offline (iPhone/iPad app by 永 张.)

- Source: https://appshunter.io/ios/app/actinic-exposure-calculator/id6787106769 (this page in markdown: same URL + `.md`)
- Developer: [永 张](https://appshunter.io/developer/1806535769)
- Category: Utilities
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 26.0 · 1 MB
- Languages: English, Chinese
- Released: 2026-07-09
- Data updated: 2026-08-16
- User reviews in markdown: https://appshunter.io/ios/app/actinic-exposure-calculator/id6787106769/reviews.md

## What is Actinic?

Actinic is a fast, fully offline exposure calculator built for film photographers — a film exposure calculator that also solves the one thing most light-meter apps skip: reciprocity failure on long exposures.

Dial in a Sunny 16 reading or your own aperture, shutter, and ISO, then read the full wheel of equivalent exposures instantly — no camera permissions, no accounts, no network calls, ever.

Shooting past a second? Pick your film stock — Tri-X, HP5 Plus, T-Max, Portra, Acros, and more — and Actinic corrects your exposure time for reciprocity failure using published manufacturer data, so your night shots and long exposures come out right the first time.

Included:
• Full-stop exposure wheel with Sunny 16 quick-set
• Reciprocity calculator with 3 built-in film stocks
• Save up to 3 camera + film presets

Actinic Pro unlocks the full 12-stock reciprocity library, unlimited saved presets, and third-stop precision to match modern camera dial clicks exactly — one-time purchase, yours forever.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Actinic Pro | $4.99 | one-time |



## Version history (last 2 releases)

### 1.0.1 — 2026-08-12

Fixed minor issues and improved overall stability.

### 1.0 — 2026-07-09

No release notes.

## More apps by 永 张

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- [NearBeam: Local File Transfer](https://appshunter.io/ios/app/nearbeam-local-file-transfer/id6777431459)

All apps by 永 张: https://appshunter.io/developer/1806535769

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-16.*