Observe one target from several heights
Keep the target and distance fixed while changing camera height. Record which named parts remain visible, then compare the predicted hidden height.
What you need
- Tripod and measurable camera-height settings
- Target with known vertical features
- Distance baseline and time/weather record
Collect the readings
- Choose a stable shore target or fixed structure with surveyed feature heights. Measure camera centre above the same surface datum used for the target. Record water level rather than substituting the tripod’s height above the pavement.
- Photograph from at least three camera heights without changing the target. Keep full uncropped frames, focal length and exposure metadata. Identify a feature’s lowest visible point, not merely whether the object appears.
- Use the curvature calculator for each height and the same distance. Start with straight rays, then compare an explicitly entered refraction scenario. Do not tune a coefficient merely to force one image to match.
- Repeat at different times with temperature and weather notes. A height-dependent change that persists across conditions differs from a transient stretched or inverted image.
Compare the predictions
Camera height changes the limiting sight line; it does not change geometric tangent drop.
Increasing zoom can resolve existing detail. It cannot create a blocked straight-light path.
Uneven terrain, waves and atmospheric layering can block or redirect paths and must be recorded.
Open the related calculation →