Last updated 20 October 2026.
Who we are
Davidson Horizon Ltd is the data controller for this site, for cinema-expert.com, cinema-tools.com, lighting-expert.net and lighting-tools.net, and for the records of its consulting work. The company is registered in Scotland, number SC651761. Contact [email protected].
What we collect
This site
Nothing. It has no accounts, no forms and no analytics. Our host, Cloudflare, keeps the request logs it needs to serve and protect the site.
Consulting
The names, work email addresses and correspondence of the people we deal with at a client. We keep them for the engagement and for our records of it.
Cinema Tools and Lighting Tools
The calculators run in your browser. Your inputs stay on your device unless you ask for a PDF by email or send an enquiry, in which case we keep the email address and the message you gave us so we can answer it.
Cinema Expert and Lighting Expert
An account is an email address. We keep that address, which modules you have access to, your quiz results and the certificates you earn. If you join a mailing list we keep the address and the list you joined.
Payments
Purchases are handled by Paddle.com Market Ltd as merchant of record. Paddle collects the payment and billing details and is the controller for them. We receive the email address on the order and the fact that it was paid. Paddle's privacy policy is at paddle.com/legal/privacy.
Why we use it
- To provide what you asked for: an account, a module, a PDF, an answer. This is performance of a contract.
- To send a mailing list you joined. This is consent, and every message has an unsubscribe link.
- To carry out a consulting engagement and keep records of it. This is performance of a contract.
- To keep records of sales and invoices for tax. This is a legal obligation.
- To keep the sites running and secure. This is our legitimate interest.
We do not sell personal data and we do not use it for advertising.
Who processes it for us
- Cloudflare, Inc. hosts the sites.
- Supabase, Inc. hosts the account database for the courses and calculators.
- Paddle.com Market Ltd handles payments.
- Microsoft hosts our email.
Some of these providers store data outside the UK. Each one does so under the UK International Data Transfer Agreement or the UK Addendum to the EU Standard Contractual Clauses.
How long we keep it
Account data stays while the account exists. Sales, invoice and engagement records stay for six years after the tax year they belong to. Enquiries are deleted once answered and no longer needed. A mailing list address is deleted when you unsubscribe.
Cookies
This site sets none. The calculators store your inputs in your own browser so they are there when you return. The courses set the cookie that keeps you signed in. Paddle's checkout sets the cookies it needs to take a payment. None of them track you across other sites.
Your rights
Under UK GDPR you can ask for a copy of your data, ask us to correct or delete it, object to how we use it, or withdraw consent. Email [email protected] and we will answer within one month. You can also complain to the Information Commissioner's Office at ico.org.uk.