Taking a spherical 360° photo
On this web page, we explain how to create a spherical 360° photo. The principle is simple, the execution is a little less so.
What is a panoramic photo ?
Let's start first with an ordinary panorama photo: in principle, you can capture a nice panorama even with one ordinary photo through a wide-angle lens. Just click the button and she's done. It becomes more difficult when you cannot capture more of the landscape with your lens in one shot: you then have to resort to taking several shots and stitching them together. We call this putting together "stitching" (the English term that actually means "stitching"). This stitching together is done by specially designed software. On today's cell phones, it is now also possible to take a video of the scene you want to record and the camera will create a panorama by itself. Simple.
What is a 360° panorama ?
In a 360° panorama, you capture everything around YOU in one flat plane. That is, you stand and move your camera parallel to the horizon and take several partial shots. The various pictures all need some overlap such that the special software has reference points to seamlessly join the pictures together. In theory, none of this is a problem were it not for the fact that lenses are not perfect and neither are the photos taken with them. Usually the corners of a photo are less exposed than the center of it. When two such pictures are put together to obtain a wider panoramic image, you will notice a "seam" because the image will be darker at that place. The better software will try to compensate for this loss of light at the sides of the picture so that the end result will be more or less enjoyable. In a 360° panoramic image, you will make one complete rotation around your axis: You will then have recorded everything that took place on the horizon around you. In the final photograph, the panorama, however, you will not be able to see what took place at your feet or above your head because ... you did not record this.
What is a spherical 360° photograph ?
In a spherical 360° photo, you take photos from a fixed point (so it remains the same as in a 360° photo) in all possible directions: including up and down. We take the photos using a special photo tripod. Special in that the head of the tripod allows the camera to be moved over exactly a number of degrees (both horizontally and vertically). Using very sophisticated software, all those images are put together into one digital model: a spherical 360° photo.
Example of a spherical 360° photo
With an ordinary screen, you cannot "just" look at a spherical 360° photo: You will have to tell your computer in which direction you want to look and with which viewing angle. Usually you can indicate with arrows on your keyboard in which direction you want to view the picture and with your mouse wheel how much you want to zoom in or out. Take a look at the example of the spherical 360° photo we took in this beautiful church in Koksijde, Belgium. Try out changing direction and angle of view.
Tip: You get the best picture when you work in full screen mode.
Special tripod to take a spherical 360° photo
So to arrive at this result, a camera was placed on a special photo tripod. Images were then taken in 72 possible directions. The number of shots one needs to take obviously depends on which lens one uses: if one zooms in strongly (with a telephoto lens, for example), then one may need to take hundreds of shots to have captured everything in all directions. If, as we usually do, we use a 35 mm wide-angle lens, then 72 shots may suffice. Each of the shots then has sufficient overlap with at least a number of neighboring shots. This overlap is necessary because the software needs to recognize points in the scene: points that then appear in at least 2 pictures and through which they can be linked.
The tripod is also special to the extent that it allows the camera with lens to be mounted slightly offset from the centerline of the tripod . Because we rotate with the camera/lens, it is imperative that we rotate through the optical center of the lens, not the camera body. By placing the lens, and not the camera, perfectly above the pivot point of the tripod, we avoid so-called parallax errors.
The 2 pictures below show the special mount in action. You will notice that the center of the lens (not the camera!) always remains neatly above the pivot point of the tripod, and this regardless of the direction in which one is shooting.
What is an HDR spherical 360° photo ?
If one wants to do HDR photography, one will have to take multiple shots for each of those directions. HDR stands for "High Dynamic Range". In this process you get pictures that better represent the dark and bright parts of a picture. Therefore, you will usually take 3 (or sometimes 5) pictures of the same scene (direction): one picture that is underexposed, one that is correctly exposed and one that is overexposed. These shots are already processed per direction into one new HDR shot. And it's those 72 HDR photos that are then brought together once again to form one spherical 360° photo.
A spherical 360° photo requires a lot from a computer
Just a quick note that creating a spherical 360°, especially if it is a HR (high-resolution) and HDR, requires a particularly large amount of computing power and storage capacity. Let's do the math together for a moment:
- one frame easily takes up 40 to 50 MB
- 3 images are shot per direction: so 3 x 45 MB = 135 MB
- 72 different directions are shot: so 72 x 135 MB = 9.720 GB of disk space, rounded up 10 GB.
In principle, however, it will be much more, but we'll spare you the technical "details."
The image obtained in this case may consist of 48914 x 24457 = 1,196,289,698, say one billion image points.
Know that if you even have a 4K monitor, it can only display about 8,294,400 image points at one time. So our spherical image contains 144 times more information than what one 4K monitor can display at most. Hence, you always have to say in which direction you want to view the picture and with which viewing angle: you will always get to see one, more or less small, piece of the big panorama.
Tools used to take a spherical 360° photo
Recording is done with a professional camera. These days this is a Canon EOS R5 (45 megapixel).
We use one of Canon's sharpest lenses ever: a 35 mm L lens (with EF-RF adapter).
We work with a specialized tripod head from Nodal Ninja: the Nodal Ninja 6 Panoramic Head With RD10 Advanced Rotator.
We use one of the references in the field of 360° composition software namely the PRO version of PTGui.
The resulting 360° model undergoes final editing in Adobe Photoshop Creative Suite.
Finally, the final result is stored on the servers of 360cities.net . They send the results to Google Earth and provide licenses.
Decision related to spherical 360° photography
Making a spherical 360° photo requires a lot of preparation and perseverance. You need the necessary tools (hardware and software) which makes the whole thing not exactly cheap. But the result is literally impressive!
