A 16-billion-pixel image of Leonardo da Vinci’s The Last Supper — said to be the world’s highest-resolution photo — went online Saturday, making the masterpiece available for scrutiny by art lovers everywhere.

White-robed Dominican monks opened the doors of their sacristy to unveil the high-res image of the painting on a giant screen just steps away from the real thing at the church of Santa Maria delle Grazie.

The digitized version, produced using special techniques designed to protect the fragile painting from damaging light exposure, gives anyone with an internet connection a chance to dig deeper into Leonardo’s techniques than ever before.

With the air of chiding an old friend, Leonardo expert Pietro Marani zoomed in on the cuff of traitor Judas to show the gold flake Leonardo applied.

“He went against his own better judgment here,” Marani said. “We know he considered using real gold a cop-out, that he thought true artists should be able to make paint glitter like gold, but there it is.”

For a close-up on the workings of a genius, Marani recommended viewers search the Last Supper for the church bell tower and shrubs outside the windows, the patterns and wrinkles in the tablecloth, the reflection of an orange wedge in a pewter plate in front of Matthew and the perspective lines in the upper left-hand corner that lead (imperfectly) to Jesus’ eye.

Leonardo used oil and tempera paints on dry plaster, an experimental technique, and as a result, the Last Supper is now so faded and cracked it can’t withstand exposure to bright light. To protect the painting, HAL9000 worked with restoration specialists at Rome’s Istituto Centrale per il Restauro to develop a lighting system without the ultraviolet emissions and high thermal impact so hazardous to works of art. Shot with a Nikon D2X digital SLR in just nine hours, the total impact of the digitization process was equal to just a few minutes of the soft lighting that normally illuminates the painting.

More from zoomata’s Nicole Martinelli at Wired.