Lenses and Focus
Lens Distortion Percentage Calculator
Calculate displacement as a percentage of ideal image height.
Enter the optical values
For Lens Distortion Percentage, keep sensor format, units, focus state, and reference planes attached to the entries.
The lens or focus result will appear here with supporting checks.
Check the lens approximation for Lens Distortion Percentage
Calculate displacement as a percentage of ideal image height.
Lens Distortion Percentage Calculator reports distortion from Ideal image height, Measured image height. Quantify radial displacement relative to ideal image height.
Thin-lens formulas are transparent starting points, but internal focusing can change effective focal length and pupil positions.
Inputs that define distortion
Record Ideal image height and Measured image height from one camera, lens, focus setting, and frame. Preserve the unit printed beside Ideal image height and Measured image height; converting one without the other changes the geometry behind distortion.
Identify whether Ideal image height came from EXIF, the lens scale, a test frame, a sensor specification, or direct measurement before comparing another Lens Distortion Percentage setup.
The calculation behind Lens Distortion Percentage
Calculate displacement as a percentage of ideal image height.
For Lens Distortion Percentage, the page keeps the intermediate geometry visible and rounds only the displayed distortion. Use a measured frame width to audit the theoretical result.
Where the distortion model stops
The sign convention reports outward displacement as positive and inward displacement as negative.
Distortion cannot judge the lens rendering, autofocus repeatability, decentering, field curvature, contrast, stabilization, or the success of the intended composition.
Worked check with the published values
For Lens Distortion Percentage, calculate the defaults and save the displayed distortion with its supporting quantities. Change only Ideal image height in the Lens Distortion Percentage example, predict the direction of distortion, and calculate again.
Restore Ideal image height and confirm the first result returns. That reset test distinguishes a real change in distortion from a stale Ideal image height value or an unnoticed unit conversion.
Measurement boundary for Lens Distortion Percentage
Define the reference plane for Ideal image height and what is included in Measured image height. For Lens Distortion Percentage, a distance referenced to the sensor cannot silently replace one measured from the lens front, mount, principal plane, or subject surface.
For Lens Distortion Percentage, list any crop, correction profile, teleconverter, extension, close-up element, breathing, or shift already represented by Measured image height. Apply each Lens Distortion Percentage adjustment once—either inside the entered measurement or explicitly afterward, never in both places.
Reading the result in practice
Compare distortion with a test frame, focus chart, measured field width, sensor specification, or known limiting case. If that check disagrees with distortion, inspect the units and the reference plane used for Ideal image height before changing the formula.
The Anamorphic Desqueeze Calculator addresses a nearby lens question, but its output should be transferred only when the format and geometry remain the same.
Precision and available settings
Keep full precision while distortion feeds another calculation, then round to the precision supported by the lens scale, rail, sensor specification, or field measurement.
Extra decimals in distortion cannot repair uncertainty in Ideal image height, Measured image height, pupil location, focus breathing, or the selected sharpness criterion.
Saving a reproducible lens record
Save Ideal image height, Measured image height, distortion, camera format, lens state, focus distance, and date. Mark nominal specifications separately from measured values.
For Lens Distortion Percentage, when the lens, format, crop, focus, or camera position changes, preserve the earlier Lens Distortion Percentage case and calculate a labeled replacement.
Designing a useful test for Lens Distortion Percentage
For Lens Distortion Percentage, choose a subject with measurable edges or planes and keep the camera position fixed unless distance is the quantity under test. Record Ideal image height before the first frame and confirm Measured image height from the same lens state. For Lens Distortion Percentage, note the marked focal length and focus state beside Ideal image height; internal focusing or zoom position can change the effective geometry.
After the published Lens Distortion Percentage baseline, create a second case that changes only Measured image height by a measurable amount. A doubled distance, one-stop aperture change, known crop, measured rail movement, or fixed pixel dimension gives distortion an independent directional expectation.
For Lens Distortion Percentage, inspect both center and edge when using distortion; projection, coverage, vignetting, distortion, diffraction, or field curvature may vary across the image. A center-frame Lens Distortion Percentage measurement may agree while the edge departs because of behavior outside this simplified equation.
Using distortion in a shooting decision
For Lens Distortion Percentage, translate the number into one concrete choice: move the camera, change focal length, select an aperture, set a rail position, confirm image-circle coverage, or decide whether the subject will occupy enough pixels. Keep that action beside the saved distortion so another person knows why the calculation was made.
If distortion falls between marked Lens Distortion Percentage controls, retain the unrounded value and document the setting actually used. Test the neighboring available Measured image height value instead of claiming more adjustment precision than the lens, rail, focus scale, tilt mechanism, or camera position provides.
For Lens Distortion Percentage, after the photograph, compare the recorded frame with the expected distortion. Save deviations that repeat across tests; they can reveal focus breathing, a nominal sensor dimension, an entrance-pupil offset, a lens-specific projection, or another stable correction worth applying in future Lens Distortion Percentage work.
Questions about lens distortion percentage calculator
What does Lens Distortion Percentage Calculator calculate?
It calculates distortion from Ideal image height, Measured image height. Calculate displacement as a percentage of ideal image height.
Which measurement should I verify first?
Confirm Ideal image height, its unit, and its reference plane before using the other entries.
What is the main limitation?
The sign convention reports outward displacement as positive and inward displacement as negative.
How can I check distortion?
Run the defaults, change only Measured image height, predict the direction, and restore the starting value.
What should I save with the answer?
Retain every input, unit, camera format, lens state, focus reference, and the displayed distortion.