Jeffrey Martin, a pioneer in the field of 360-degree photography, has been living in Prague for a quarter of a century. Recently his company Mosaic launched a 15-terapixel open-source data set of high resolution street view imagery of the city. How is this incredibly detailed mapping carried out? And who are the many users already accessing the resource, which is free for non-commercial use? I spoke to Martin, who is from the US, in a small park near his office in the Smíchov district.