By now, you’ve almost surely come into contact with spherical panoramas. Google Street View is probably the most ubiquitous use of the spherical panoramic photo (AKA photosphere, panosphere, or pano). You don’t need a fancy car with 15 cameras mounted to the roof to take spherical panoramas. You can do it with a camera, a wide lens, and some software.
Spherical panoramas rely on wide photos stitched together to capture the full 360° field of view. Many devices make photospheres on their own with integrated software; the Ricoh Theta and GoPro Fusion 360° cameras can record spherical video, and most of the DJI drones have a functionality that lets users shoot spherical still photos. For those without a fancy camera or who want more control over their imagery, there are dozens of pano stitching options for PC and Mac. My choice is PTGui (Pano Tools Graphic User Interface, pronounced PT Gooey).
You may be wondering how I got such straight (red) lines between images in the pano to the right, and it has nothing to do with a steady hand or an ability to precisely measure 90° (90° x 4 = 360°) and rotate my camera accordingly. Instead, I have instruments that do both things.
The first instrument is a tripod with a ball head (to the left). I use a MeFoto Road Trip carbon fiber tripod with built-in ball head. This is the best tripod I have ever owned. The legs expand and contract in a flash. Despite being ultra-light and transportable, it’s very stable, and if I need extra weight, it has a retractable hook on the center column. The ball head (instead of a traditional head with a lever controlling pitch) is important, first for keeping the camera upright within a small margin of error, and second, because of the low profile, less of the tripod is captured by my super-wide lens (to the right). In my case, a Sigma 8mm fisheye which gives an impressive 180° field of view. If you look closely at the images below, you can see the feet of my tripod at the very bottom of the image. These are normally covered by my nadir patch. (A note on nadir patching.)
The second instrument is called a pano-head rotator. I use the Nodal Ninja R10 by Fanotec with a 10-degree static tilt (this upward tilt is the reason for the small black square at the bottom nadir of all my pano’s. With PTGui, I can fill in the bottom with the actual content (replacing the black square and the tripod legs, but it’s a time-consuming process and not worth the hassle in most cases. For those who are interested, see my note on nadir patching.) The pano-head rotator is a simple piece of equipment, but an important one. The R10 is a lens-mounted rotator, and I use it to position the camera precisely with every shot while I’m shooting panos. The spinning plate in the Nodal Ninja has four notches at intervals of 90°. For uniformity, I usually start with a photo facing due north. Pushing the camera very slightly, I rotate it to face due east (or west–the direction is not very important, but we need all four cardinal directions), due south, and then due west.
Since the exposure value will differ greatly from one part of a pano to the next (just think about the room you’re in; while the windows are very bright during the day, the corners with no direct light will be dark), I use HDR bracketing to even things out. HDR stands for high dynamic range, and I use an exposure compensation of ± 2 EV ( ± 2 full stops). I use a fairly high f-stop (usually f8-f10 or so. Since my camera is mounted on a tripod, I’m not worried about steadiness and can use very low shutter speeds, especially for the +2 EV shots.) To take bracketed photos, my camera takes a series of three photos keeping ISO and aperture the same and varying the shutter speed. Taking three shots in each direction yields 12 photos per pano. Now that I have my source images, I can proceed to stitching them with PTGui.
With the hefty price tag of $140 USD (the free trial version restricts some functionality and puts watermarks on your output jpg’s), PTGui is one of your most expensive options, but it has literally thousands of options for adjusting panoramas before and during the stitching process. As someone who takes dozens and sometimes hundreds of pano photos at a time, I absolutely love their batch stitcher. I just dump my raw photo files into a folder on my computer, point the batch stitcher at that folder, and it does the rest. It also creates project files for each pano; if some happen to come out screwy, they are easily remedied.
With the correct source images, (as well as most other computer programs) PTGui will render an image that is 2 x 1 in dimensions and 360° horizontal by 180° vertical. Now that our panos match those parameters, it’s time to find a driver for them and upload. (A driver is a program, such as Google Photos, Facebook, Spinattic, and other sites that will turn your 2-D rectangular photos into a rotate-able 3-D sphere.) My favorite driver is Google Maps, which lets me embed the images on my website, like so:
I would like to talk now about another driver service, called Spinattic. Not nearly as powerful or ubiquitous as Google Photos and Street View, the service has been in beta testing for nearly ten years. Spinattic, in contrast to Google Maps, has no restrictions on the content allowed. (Google forbids Trusted Photographers from uploading imagery of a couple types of places, notably private houses, which means that some Airbnb customers do not qualify for a Virtual Tour hosted on Google Maps. Spinattic is therefore a substituted) Also, Spinattic has some user friendly settings. Instead of geolocating each individual scene (pano) of every Virtual Tour, and populating the images with navigational arrows based on the directions between them to allow the user to move from one scene to the next, adjacent scene, Spinattic shows all the panos along a panel below the active pano, and the user can choose which scene she would like to see. Also, the tour reator can add “hotspots,” that appear as arrows and jump to another pano within the tour or even to a custom URL.
Spinattic also lets you add “spin” to your images and embed them in websites. The user can choose an intial point, delay time, and rotation speed. After the indicated delay time, the pano will rotate back to horizontal and begin rotating at the indicated speed. The viewer can pause the rotation (at high speeds, it can be somewhat dizzying or just unpleasant) by hitting the space bar or clicking the circular arrow button.