Last updated 20 October 2026.
Who you are dealing with
Davidson Horizon Ltd, registered in Scotland, number SC651761, registered office Mckellar Accountancy, Unit Studio 2001 Mile End Mill, Abbey Mill Business Centre, 12 Seedhill Road, Paisley, PA1 1JS. Contact [email protected].
Consulting
Consulting is provided to businesses under a written engagement that sets out the scope, the fee and the payment terms. Nothing on this site is an offer to provide consulting, and these terms do not apply to it.
Training
Cinema Expert and Lighting Expert modules are sold through Paddle.com Market Ltd, our merchant of record. Paddle is the seller on your receipt and handles the payment, VAT and sales tax. Paddle's buyer terms are at paddle.com/legal/buyer-terms.
A purchase gives the account on the order access to the module you bought, on the course website, for as long as the course is published. Access is personal to that account and cannot be transferred or shared.
Refunds
Ask for a refund within 14 days of purchase by emailing [email protected] with the order reference. If you have not completed the module's quiz we refund in full. Paddle returns the money to the payment method you used. This does not limit your statutory rights as a consumer.
Certificates
A certificate records that the named person completed a module. It is not a qualification and it certifies no room. We confirm a certificate only to the person named on it, or to someone who gives us both the reference and the name.
The calculators
Cinema Tools and Lighting Tools are free. No purchase is needed and none is offered. The calculators give idealised results from the numbers you enter. They are an aid to a designer, and the designer is responsible for the design.
Software
Probata is in development and not yet on sale. Its licence terms will be published with it, here and in the app stores that distribute it.
Using the content
The course text, videos, figures and quizzes, and the text and artwork on this site, are the copyright of Davidson Horizon Ltd. You may use them for your own learning. You may not copy, publish or resell them.
Law
These terms are governed by the law of Scotland. Disputes go to the Scottish courts, unless you are a consumer with a right to bring them in your own country.