Explanation
Equirectangular projection is an image format that transforms a complete spherical view (360° horizontal x 180° vertical) into a flat rectangle with a 2:1 aspect ratio. It is the standard format used to store, edit, and distribute 360° photos and videos. Just like a world map that "unfolds" the globe into a rectangle, equirectangular projection unfolds the 360° sphere into a flat image that software and immersive viewers can process.
Real-world example
The world map you see in atlases, which stretches the poles and compresses the equator — it is exactly the same projection principle applied to 360° content.
Practical applications
- Export 360° panoramas in equirectangular format to import them into a virtual tour platform
- Edit and retouch 360° images in Photoshop or Lightroom in equirectangular format before distribution
- Understand the visual distortions at the poles (zenith and nadir) in order to correct them before publishing
- Convert between equirectangular and cubemap formats depending on the viewer or platform requirements
360° projection formats
Equirectangular projection (standard)
- Rectangular image with a 2:1 ratio (e.g. 8192x4096 pixels)
- The most universal and compatible format
- Increasing distortion toward the poles (top and bottom of the image)
- Single file, easy to store, transfer, and edit
Example: An 8192x4096-pixel JPEG file containing a complete 360° panorama of a living room, editable in Photoshop
Cubemap projection (alternative)
- 6 faces of a cube representing the 6 directions (front, back, left, right, top, bottom)
- Minimal distortion on each face
- Used for real-time rendering in 3D engines (Unity, Unreal)
- Automatic conversion from equirectangular by viewers
Example: A skybox in Unity composed of 6 square images forming the faces of a virtual cube
VR scenario
A 360° photographer captures a panorama with an Insta360 camera. The app exports the result in equirectangular format: a rectangular image with a 2:1 ratio where the floor is heavily stretched at the bottom and the ceiling at the top. The photographer retouches the brightness in Photoshop, corrects the tripod artifact at the nadir, then imports the image into EasyStory 360. The platform automatically re-projects the flat image onto a sphere, restoring the natural 360° view for the visitor.
Why it matters in professional VR
- Equirectangular is the industry standard for 360° content: understanding it is essential for working with immersive media
- Knowing this format allows you to retouch and optimize panoramas before publication
- The distortions at the poles require special attention during the shoot (tripod at the nadir, lighting at the zenith)
- Converting between formats (equirectangular, cubemap, multiresolution) is a common step in the 360° production pipeline