World's Largest Spherical Panorama

I've been a big fan of the panorama photos of Jeffrey Martin of 360Cities for a while now, so I was pleasantly surprised when I learned that he has just taken what could be the world's largest spherical panorama, an 18-gigapixel shot of Prague.

Here's how he did it:

I used a Canon 5d mark 2 and a 70-200mm lens, set to 200mm. The camera was mounted on a robotic device which turned the camera in tiny, precise increments, in every direction. All together, 40 gigabytes of images were shot. These images were then stitched together using PTGui. The resulting panorama was adjusted for color, contrast, sharpness, etc. in Photoshop. Afterwards, the image was cut into lots of “tiles” and uploaded to our server. When you view the image online, you only load a few of these “tiles” at one time.

How long did you spend stitching this panorama?

Between loading the initial raw files into the computer, and having the panorama stitched, it took about a week. It took 3 additional weeks to fine-tune the image.

What kind of computer did you use?

I used a four year-old windows PC with two single-core 3ghz xeon processors and 8GB of RAM. After a week of frustration, I also bought an SSD, which helped to speed up some tasks a bit. If I will make this image again, I will buy a new computer.
What is dimension of this panorama, and size it takes on disk?

The final image exists as a 120 gigabyte photoshop large (PSB) file. It cannot exist as a TIFF or JPEG file because of their size constraints. The panorama online exists as a few hundred thousand small tiles (in JPEG format), and they take up about 1 gigabyte of disk space.

Jeffrey was kind enough to invite all of us on a treasure hunt: in a couple of days, he'll release a set of clues for you to find 30 things in the photo. The first person who got it right will win $1000.

Links: The Panorama | The Treasure hunt - Thanks Jeffrey!