Teeming with images of spectacular underwater scenes from around the world, Call of the Blue is the culmination of a five-year project by the photographer and ocean conservationist Philip Hamilton. This groundbreaking book includes contributions from acclaimed scientists and ocean “guardians”, who reveal what drove them to answer the call of the blue. (Photo by Philip Hamilton/The Guardian)

Ukrainian emergency workers spray a plane with water hoses as part of a rescue training exercise at Boryspil International Airport outside Kiev, Ukraine, September 27, 2016. (Photo by Valentyn Ogirenko/Reuters)

French aircrafts of the Patrouille de France spray colored smoke during a performance on the opening day of the Dubai Airshow in Dubai, United Arab Emirates, Sunday, November 17, 2019. (Photo by Kamran Jebreili/AP Photo)

A worker sprays disinfectant at Independence Square during a disinfection operation, amid the coronavirus disease (COVID-19) outbreak in Kuala Lumpur on October 17, 2020. (Photo by Lim Huey Teng/Reuters)

A Taliban fighter walks past a beauty salon with images of women defaced using spray paint in Shar-e-Naw in Kabul on August 18, 2021. (Photo by Wakil Kohsar/AFP Photo)

A string art picture made by artist Ani Abakumova in a workshop in the village of Romashkovo in Moscow Region, Russia on August 2, 2019. Ani Abakumova and her husband Andrei Abakumov create string art replicas of famous paintings. Andrei makes computer calculations that show patterns for future images, then Ani winds coloured strings around nails hammered around a plywood board. (Photo by Anton Novoderezhkin/TASS)

Only with a pencil, ruler and protractor, without the help of a computer, Venezuelan artist Rafael Araujo creates complex fields of three dimensional space where butterflies come to life and shells rise from mathematical spirals.

Architectural photographer Victor Enrich has shared with ArchDaily a series of 88 images — one for every key in the classical piano — exploring the various formal possibilities of the NH Deutscher Kaiser Hotel in Munich, Germany. “I found it beautiful,” says Enrich, “to connect two distinct artistic disciplines such as photography and computer graphics with the piano.” See further illustrations and read a full description of his thought process following the break.