3D photography creates images that convey a sense of depth, making subjects appear to pop out of or recede behind the viewing surface. Unlike standard flat photographs, 3D images mimic the way human binocular vision perceives the world: each eye sees a slightly different angle, and the brain combines these two perspectives into a single image with depth information. 3D photography replicates this by capturing two offset views of the same scene.
Stereo Photography
The foundation of 3D photography is stereo imaging: capturing two photographs from slightly different horizontal positions, separated by roughly the distance between human eyes (about 6.5 cm). Each image represents what one eye would see. When viewed so that each eye sees only its corresponding image, the brain fuses them into a single 3D perception.
Stereo pairs can be captured with a dedicated stereo camera (two lenses mounted side by side in a single body), with two separate cameras on a bracket, or by taking two sequential photos while shifting the camera sideways between shots (for stationary subjects only). The key requirement is that the only difference between the two frames is the horizontal offset. Vertical misalignment, rotation, or changes in exposure between frames will interfere with the 3D effect and cause viewer discomfort.
Viewing Methods
Anaglyph. The two images are color-coded (typically red for the left eye and cyan for the right) and overlaid into a single image. Viewed through red-cyan glasses, each eye sees only its corresponding image. Anaglyphs are the most accessible format since they can be printed or displayed on any screen, but they sacrifice color accuracy.
Side-by-side and cross-eye. The two images are placed next to each other. Viewers either use a stereoscope, VR headset, or train their eyes to fuse the images without equipment (cross-eye or parallel viewing techniques). This preserves full color but requires practice or a viewing device.
Lenticular prints. A lenticular lens sheet is placed over a specially interlaced print so that each eye sees a different image depending on viewing angle. The result is a glasses-free 3D print that shows depth when viewed straight on and may even show a limited animation effect when tilted. Lenticular prints are used in novelty items, advertising, and fine art.
Computational 3D
Modern smartphones and software can generate 3D-like depth effects from a single lens. Dual-camera phones capture a slight stereo offset between their two lenses. Single-camera systems use machine learning to estimate depth from a single image, creating a depth map that enables synthetic background blur (bokeh), 3D photo effects, and perspective shifts. While these computational approaches are not true stereoscopy, they produce convincing depth effects for casual viewing and social media sharing.
Applications
3D photography has practical uses in architecture (visualizing spaces with realistic depth), product photography (allowing customers to perceive the shape and volume of items), scientific and medical imaging (documenting three-dimensional structures), and fine art (creating immersive visual experiences). As VR headsets become more common, stereo photography is experiencing renewed interest as a way to create immersive still-image content for virtual environments.