Plan distant framing before the subject arrives
Subject size in a photograph depends on angular size, not distance alone. A large aircraft far away can occupy less of the frame than a nearby bird. The camera field of view then determines how much of the image that angle covers.
Native detail and displayed size are different
Crop-based digital zoom enlarges the central part of an image. It can make a subject easier to see on screen, but the original sensor pixels covering that subject do not increase. This tool reports both numbers so framing and source detail are not confused.
Use realistic input values
- Use the physical focal length and sensor width from the same camera module.
- Measure distance from the camera position, not from a map label.
- Leave room around birds, aircraft and boats because moving subjects are harder to track.