A Beginner’s Guide to Photogrammetry vs Laser 3D Scanning: Tech Compared

What is Photogrammetry?

Photogrammetry is a sophisticated imaging technique that transforms two-dimensional photographs into precise three-dimensional digital representations by leveraging advanced computational algorithms and geometric principles. This method enables professionals across various industries—including archaeology, film production, urban planning, and surveying—to create accurate 3D models without direct physical contact with the subject.

The core process of photogrammetry involves several intricate technical steps:

• Image Capture Strategy: Systematically photographing an object or landscape from multiple strategic angles, ensuring significant overlap (typically 60-80%) between consecutive images to facilitate comprehensive spatial reconstruction
• Feature Detection: Utilizing advanced computer vision algorithms to automatically identify and match distinctive pixel patterns and geometric features across different photographs
• Point Cloud Generation: Mathematically triangulating precise spatial coordinates by comparing matched points, creating a dense three-dimensional point cloud representation
• 3D Model Reconstruction: Transforming the point cloud data into a textured, geometrically accurate digital model using specialized photogrammetry software

Unlike traditional 3D scanning methods, photogrammetry leverages computational power and standard photography equipment, making it an increasingly accessible and versatile digital reconstruction technique for professionals and enthusiasts alike.

What is Laser 3D Scanning?

Laser scanning, also known as LiDAR (Light Detection and Ranging), is an advanced remote sensing technology that uses laser beams to measure distances and create precise 3D point clouds. This sophisticated method captures spatial information by employing several key technical principles:

• Emits laser pulses that bounce off surfaces with remarkable precision
• Calculates exact distances using time-of-flight measurements
• Generates highly accurate spatial representations

The core mechanism of laser 3D scanning involves projecting millions of laser points across a target area, creating a dense network of measured coordinates. Each laser pulse travels at the speed of light, hitting surfaces and reflecting back to specialized sensors that record the exact time and angle of return. By calculating the time difference between emission and reception, the scanner can determine precise distances with sub-millimeter accuracy.

Different laser scanning technologies include terrestrial, airborne, and mobile systems, each optimized for specific environmental and application requirements. Industrial-grade scanners can capture complex geometries in manufacturing, architectural preservation, geological surveys, and forensic investigations with unprecedented detail.