What kind of photos are used for photogrammetry purposes?

Technically photos for photogrammetric purposes can be captured with any camera. But some things do work better than others. Photogrammetric algorithms work best with generally high-quality imagery. High quality photos can be obtained from many types of imaging devices as longs the technique and specifications are up to the job.

A few key specifications regarding the equipment are recommended:

  1. Resolution: 12 megapixels is a good starting point. Any less than that introduces a little risk that not enough detail could be captured for good 3D reconstruction results.
  2. Lens focal length: anything between 16 and 135 millimeters of 35 mm equivalency should be good for photogrammetry, sweet spot being 24 - 50 mm equivalent lenses. All manufacturers specify the equivalent lens focal length because it’s the most common unit to determine how wide or zoomed-in the lens is. Always refer to the cameras or lens' manual to find the equivalent focal length. Anything wider (less) than 16 millimeters is ultra-wide angle which might introduce heavy distortion that might compromise reconstruction results. Anything longer or more 'tele' than 135 millimeters can result in shallow depth of field which also can make 3D reconstruction impossible. Specialty lenses such as fish-eye, tilt-shift, soft-focus should be generally avoided. Although macro lenses are usually well suited for photogrammetry due to their excellent optical properties.
  3. GPS geotagging: GPS data embedded in the photo helps to create projects with scale and position which is required if any measurements are to be made. This is most applicable to drones. Almost all drones embed GPS data because having a GPS sensor is an essential part of their operation. Some handheld cameras and most smartphones have GPS as well.