Privacy Policy

Effective date: February 15, 2026

The short version: Zeus Focus Stacking processes all your images entirely on your device. We do not collect, transmit, or store your photos, personal data, or usage analytics. Your privacy is absolute.

1. Image Processing

All image capture, alignment, and focus stacking is performed entirely on your device using the GPU (Metal compute shaders). Your photos are never uploaded to any server. The processed results are saved to your device's photo library only when you choose to save them.

2. Data We Do Not Collect

Zeus Focus Stacking does not collect any of the following:

Photos or images
Personal information (name, email, phone number)
Device identifiers or advertising IDs
Usage analytics or behavioral data
Crash reports (we do not use third-party crash reporting SDKs)
Location data transmitted to servers

3. Location Data

If you grant location permission, Zeus Focus Stacking saves the GPS coordinates of your capture sessions locally on your device using SwiftData. This allows you to browse your stacking projects on a map within the app. Location data is never transmitted to any external server or third party.

Location access is optional. The app functions fully without it.

4. Lens Breathing Calibration Data

Zeus Focus Stacking may download lens calibration profiles from Firebase Cloud Storage to improve alignment accuracy. This is a one-way download:

The app downloads pre-computed calibration data for your lens model
No user data, device information, or photos are sent to the server
Downloaded calibration data is cached locally in the app's storage
The Firebase project used is zeus-calibration

5. Camera and Photo Library Access

Zeus Focus Stacking requests access to:

Camera — to capture focus-bracketed images for stacking
Photo Library (write) — to save your stacked results
Location (optional) — to geotag your stacking projects locally

These permissions are used solely for in-app functionality. No data from these sources is transmitted externally.

6. Third-Party Services

Zeus Focus Stacking does not integrate any third-party analytics, advertising, or tracking SDKs. The only external service used is Firebase Cloud Storage for downloading lens calibration profiles (see Section 4).

7. User Accounts

Zeus Focus Stacking does not require or support user accounts. There is no sign-up, login, or authentication of any kind.

8. In-App Purchases

Purchase transactions are handled entirely by Apple through the App Store. Zeus Focus Stacking does not process, store, or have access to any payment information.

9. Children's Privacy

Zeus Focus Stacking does not knowingly collect any data from children or any other users. Since no personal data is collected from anyone, the app complies with COPPA and similar regulations by design.

10. Data Security

Since no user data is collected or transmitted, there is no data to secure on our end. All your images and project data remain on your device, protected by iOS's built-in security features including device encryption and app sandboxing.

11. Changes to This Policy

If we make changes to this privacy policy, we will update the effective date at the top of this page. Material changes will be communicated through an app update.

12. Contact

If you have questions about this privacy policy, contact us at:

privacy@zeusfocusstacking.com