In the sequel, the projected pixel size means the extension of the classical ground resolution to a more general, possibly not aerial, acquisition configuration.

The resolution and precision of the generated 3D model is directly related to the projected pixel size on the subject. In order to achieve a desired projected pixel size, you must adopt a proper combination of focal length and distance to the subject, as defined by the formula below:

projected pixel size × focal length × photo's largest dimension = sensor width × distance to the subject

[m / pixel] [mm] [pixel] [mm] [m]

Uniform projected pixel size across the entire image is not required since ContextCapture will automatically propagate variations in projected pixel size to the resolution and precision of the generated 3D model. ContextCapture is unable, however, to join together photographs of radically different projected pixel sizes. If a wide range is required, photographs with intermediate values should be used to create a smooth transition.