In the frame of the International Day of Light, celebrating Light and Optics, with the support of the Lviv Polytechnic National University, the Hands-on Science Network and the Portuguese Society for Optics and Photonics organize another edition of informal digital photography contest, X Informal Digital Photography Contest "The Light and the City".

The photos must be taken in the period May 16 to July 1, 2026, and should focus on the Light and its relation to the Town/City you live in or visit.

Photos can be digitally edited/processed.

The photos (up to 3 per participant) should be sent to hsci2026[at]ukr.net, by July 1 at 23:59 GMT+2 (the name of each picture file should include an abbreviated title/name of the photo and the first name initial and last name of the author). The results will be announced at the closing ceremony of the HSCI2026 conference - July 3, 2026 at 12:00 (GMT+2).