ImageReasonLenses, Field of View, and System Equivalence
How much image circle does my shift actually need?
Enter your sensor dimensions and intended shift to see the required geometric image-circle diameter, then compare it against your lens's stated coverage.
Answer
Want to learn more? Framing, Perspective, Equivalence, and Image Circles
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Calculate to see the sensor-in-circle diagram.
| Shift Y | Required circle |
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Calculate a result to generate a copyable plan.
Shift solves coverage placement, not perspective
Shift solves a coverage-placement problem when the lens projects a sufficiently large image circle. It does not by itself solve perspective. Keeping the camera level and choosing position still governs how parallel lines appear. This planner separates the geometry of a shifted sensor from the composition and lens-compatibility decisions that must follow.
A 36×24mm sensor needs a geometric image circle of about 43.3mm even without shift. Move the sensor 10mm vertically and the required circle rises to 50mm. A lens with only a 44mm usable circle may cover an unshifted full-frame sensor but not the shifted position. Confirm actual lens movements and image-circle specifications, then leave composition margin rather than framing against the absolute edge.
This result models the values you entered. It cannot see the scene, verify focus or movement, predict camera-specific processing, or guarantee the final photograph. Use it as a stated starting point, then check the important subject area in a test frame or proof.
Make one controlled test with the important variable held constant. Inspect the subject detail, motion, highlights, and intended output, then adjust the setting that protects the priority you named.
FAQ
- Will a shift lens make building lines straight?
- A level camera and correct position are the important geometry. Shift can reframe while keeping that camera orientation, but it does not guarantee a particular result.
- Why no universal best setting?
- There is no universal best setting because the relevant tradeoff changes with the subject, light, movement, output, and the part of the image that matters. This tool makes the stated tradeoff visible rather than hiding it behind a generic recommendation.