In order to access the Helioscreen Lighttool calculator please fill in this form. Helioscreen will provide you with a login and password for your personal account. Subscribe for the online & download version: € 250 per year. The download version is available for Windows-platforms only. System requirements: 800Mb of free space & 600Mb for swap-files 256 Mb Ram Windows operation system Subscribe for a free trial version of Helioscreen Lighttool. Helioscreen will provide you with a temporary login and password, which can be used 3 times. The trial version is only available on the internet.