Last updated: July 9, 2026
Terms of Use & End-User License Agreement
Calibration Flow is published by Tristan Sidem, sole proprietor (French "entrepreneur individuel" / micro-entreprise), SIREN 528 977 275, registered address 1 passage Dagorno, 75020 Paris, France. Contact: tristan.sidem@gmail.com.
Using the Calibration Flow app and website (web, iOS, macOS) means you accept these terms in full.
1. Purpose of the service
Calibration Flow is a tonal-calibration tool for alternative photographic printing processes (cyanotype, platinum-palladium, Aquaprint/gum bichromate, carbon, Van Dyke, resinotype, etc.). It measures a calibration target via your camera, generates a correction curve you can export (.acv), and turns images into digital negatives.
2. Access to the service
Access requires creating an account (email, Google, or Sign in with Apple). Two tiers are offered:
- Free tier — full calibration workflow, up to 3 synced curves and 300 MB of cloud storage.
- Pro tier — €9.90/month (or €129/year), unlimited curves, 5 GB of cloud storage, CMYK Color Venn and advanced export options, on web and iOS/macOS with a single account. A Luminograph purchase from Vision Picturale includes 1 year of Pro at no extra cost.
3. Subscription, billing and cancellation
On iOS and macOS, the Pro subscription is managed through Apple's in-app purchase system (App Store): billing, automatic renewal and cancellation follow Apple's rules and are managed from your Apple ID settings. On the web, the subscription is managed through Stripe; it has no commitment and can be cancelled at any time from your account area, with Pro access remaining active until the end of the period already paid for. We never receive your card details.
As access to paid features is available immediately after purchase with your explicit consent, the standard 14-day withdrawal period does not apply once the service has started, except where the payment platform used provides otherwise.
4. Intellectual property
The app, its code and design remain the publisher's property. Content you create (curves, presets, imported or scanned media, generated images) remains yours; you only grant us the technical right to store and sync it in order to provide the service.
5. Liability
Calibration Flow is a calibration aid; it does not guarantee any specific photochemical outcome, which depends on many factors specific to each darkroom (paper, chemistry, UV source, printing conditions). You remain solely responsible for handling chemicals and UV exposure related to your printing processes, including through any connected-equipment control feature (Bluetooth UV lamp) offered by the app.
6. Account termination
You may delete your account at any time by contacting us at tristan.sidem@gmail.com. Deletion erases your cloud content, subject to any legal retention obligations.
7. Governing law
These terms are governed by French law. In the event of a dispute, an amicable resolution will be sought before any legal action.
8. Changes
These terms may evolve; the last-updated date is shown at the top of the page. You will be notified in the app of any significant change.
9. Contact
For any question: tristan.sidem@gmail.com.