Terms of Service
1. Who we are
T-Stop Pro is an iOS application and website provided by James Coote, an individual trading as T-Stop Pro. In these terms, "we", "us" and "our" mean James Coote. "You" means the person using T-Stop Pro.
Contact: james@tstoppro.com
2. Agreement to these terms
By downloading, installing or using the T-Stop Pro app, or by using tstoppro.com (including the online calculator), you agree to these terms. If you do not agree, do not use T-Stop Pro.
If you obtained the app from the Apple App Store, Apple's own terms also apply to that download and to any purchase you make inside the app. Where Apple's terms conflict with ours in relation to an App Store transaction, Apple's terms govern that transaction.
3. What T-Stop Pro is
T-Stop Pro is a cinematography exposure calculator. It holds a database of lighting fixtures with published photometric figures, and it estimates illuminance and the resulting T-stop at a subject for a chosen fixture, distance, colour temperature, camera setting and, where you select them, gels and modifiers.
4. Accuracy: read this before you rely on a number
T-Stop Pro produces estimates, not measurements. Its figures are derived from data published by fixture manufacturers, from our own modelling and interpolation between published data points, and from general photometric theory. They are not a substitute for a light meter on set.
Real-world results vary with lamp age, power supply and voltage, dimmer curves, firmware, ambient and bounced light, lens and filter transmission, sensor calibration, manufacturing tolerance between units, and errors or omissions in the manufacturer data we rely on.
You must verify critical exposure with a meter and a test. Do not use T-Stop Pro as the sole basis for any decision where being wrong would cost you money, a shot, a day, or safety. We give no warranty that any photometric figure, T-stop, exposure value or stop-loss shown in the app is accurate, complete or fit for any particular production.
Fixture names, model numbers and manufacturer brands appear in T-Stop Pro for identification only. They are the trademarks of their respective owners. T-Stop Pro is not affiliated with, endorsed by, or certified by any fixture manufacturer.
5. Your account
Some features require an account. You agree to give accurate registration details, to keep your sign-in credentials secure, and not to share your account. You are responsible for activity under your account.
You can delete your account and its data at any time from inside the app, or by emailing james@tstoppro.com. Deleting your account does not automatically refund a purchase.
6. Free features and paid features
The full fixture catalogue and the core T-stop calculation are free to use. Some professional features are unlocked by a purchase. Which features sit on each side of that line is stated in the app at the point of purchase, and we may adjust it as the product develops. Anything you have already paid for stays unlocked.
7. Purchases
You can buy an unlock in two places, and they are governed differently.
In the app (Apple In-App Purchase)
- Payment is taken by Apple, not by us. Apple is the merchant of record and its Media Services Terms and Conditions apply.
- Prices are shown in your local currency in the App Store before you confirm.
- Any subscription renews automatically until you cancel it, and you cancel it in your Apple ID settings, not in the app. Cancelling stops the next renewal; it does not shorten the period you have already paid for.
- Refunds for App Store purchases are handled by Apple under Apple's refund policy. We cannot issue or reverse an App Store charge.
On tstoppro.com (Stripe)
- Payment is taken through Stripe on a checkout page operated for us by RevenueCat. We are the seller for these purchases.
- The price on that checkout page is the authoritative price for a web purchase.
- A web purchase unlocks the same features in the app. You link it to your T-Stop Pro account, and the same features are also available to buy as an in-app purchase.
- If you buy before the app is available to you, and we are unable to deliver the unlock to your account, contact us and we will refund you in full.
Consumer cancellation rights (UK and EU)
If you are a consumer in the UK or the EU, you normally have 14 days to cancel a purchase of digital content bought from us on the web. By starting to use the unlock within that period you ask us to begin supply immediately and you acknowledge that you lose that cancellation right once supply has begun. This does not affect your rights if the content is faulty or not as described.
"Lifetime" access
A lifetime unlock is a one-off payment with no renewal. It lasts for as long as we keep operating T-Stop Pro. It is personal to your account, is not transferable, and is not a promise that the app or any individual feature will exist forever.
8. Acceptable use
You agree not to:
- copy, scrape, bulk-extract, republish or resell the fixture database or any substantial part of it;
- reverse engineer, decompile or attempt to derive the source code of the app or its calculation engine, except to the extent the law says you may;
- circumvent any purchase, licensing or access control;
- use T-Stop Pro to build or train a competing product or dataset;
- use T-Stop Pro unlawfully, or in a way that disrupts the service for others.
9. Intellectual property
We own, or are licensed to use, the app, the website, the calculation engine, the compiled fixture database and everything we publish. We grant you a personal, limited, non-exclusive, non-transferable, revocable licence to use T-Stop Pro for your own cinematography work, including commercial productions you work on.
Setups and presets you create are yours. You grant us only the permission we need to store and display them back to you in the service.
10. Availability and changes
We may change, suspend or withdraw features, and we may take the service down for maintenance. We will not remove a feature you have paid for without offering a reasonable remedy. We may update these terms; if a change materially affects you we will give notice in the app or by email, and continuing to use T-Stop Pro after that means you accept the updated terms.
11. Suspension and termination
You may stop using T-Stop Pro at any time. We may suspend or end your access if you break these terms, and we will tell you why unless the law prevents us.
12. Disclaimer and limitation of liability
T-Stop Pro is provided "as is" and "as available". To the fullest extent the law allows, we exclude all implied warranties, and we do not warrant that the service will be uninterrupted, error-free, or that any figure it produces is accurate.
To the fullest extent the law allows, we are not liable for loss of profit, loss of production time, cost of reshoots, loss of data, or any indirect or consequential loss arising from your use of T-Stop Pro or from reliance on any figure it produces. Where liability cannot be excluded, our total liability to you is limited to the amount you paid us for T-Stop Pro in the 12 months before the claim.
Nothing in these terms limits liability for death or personal injury caused by negligence, for fraud, or for anything else that cannot be limited by law. If you are a consumer, nothing in these terms affects your statutory rights.
13. Dispute resolution and binding arbitration (United States users only)
If you live in the United States, you and T-Stop Pro agree that any dispute or claim arising out of or relating to these terms or your use of T-Stop Pro will be resolved by binding individual arbitration rather than in court, except that either of us may bring a qualifying claim in small-claims court. Arbitration will be handled by a recognised arbitration provider under its rules, and the arbitrator's decision is final and may be entered as a judgment in any court with jurisdiction. You may opt out of this arbitration agreement by emailing james@tstoppro.com within 30 days of first accepting these terms.
14. Class action waiver (United States users only)
To the fullest extent permitted by law, you and T-Stop Pro agree to bring claims against each other only in an individual capacity, and not as a plaintiff or class member in any class, collective or representative action. The arbitrator may not combine more than one person's claims or preside over any class or representative proceeding.
Note for UK, EU and other consumers: sections 13 and 14 apply to United States users only and do not affect any mandatory consumer rights you have under the law of your country of residence.
15. Governing law and your local consumer rights
These terms are governed by the law of England and Wales, and the courts of England and Wales have jurisdiction, except that sections 13 and 14 apply to United States users.
If you are a consumer, this choice of law cannot take away your local rights. Nothing in these terms deprives you of the protection given to you by the mandatory rules of the law of the country where you habitually live. Those rules continue to apply to you in full, and where they conflict with these terms, they win.
You can also bring proceedings in the courts of the country where you live, and the consumer authorities and dispute-resolution schemes of that country remain available to you.
16. Contact
Questions about these terms: james@tstoppro.com