Does a 1.33x lens on 16:9 make exactly 2.39:1?

No. Using 1.33 exactly gives about 2.364:1. An exact 4:3 factor gives about 2.370:1. A small crop is needed for 2.39:1, and the precise result depends on the actual lens squeeze.

Why can the desqueezed width be fractional?

The optical ratio and pixel grid are separate. Multiplying an integer recorded width by a decimal squeeze can produce a fractional nominal width, so an exported square-pixel raster must be rounded or scaled.

Is the marked squeeze factor always exact?

Not necessarily. Some anamorphic lenses breathe or change effective squeeze with focus distance. Treat the marked factor as a planning value and check critical footage with a known circular or square reference.

Does this calculator upload footage or production values?

No. It only uses the numbers entered and performs every calculation locally in the browser. It does not inspect or upload media.

Anamorphic Desqueeze Calculator — Aspect Ratio, Resolution & Crop

Enter the recorded raster and lens squeeze factor to find the corrected display ratio, square-pixel canvas, and optional crop for a 2.39:1, 2.40:1, 2.35:1, 1.85:1, or custom delivery.

Footage and lens inputs

Recorded width (px)

Integer from 1 to 100,000.

Recorded height (px)

Use the stored image height.

Lens squeeze factor

Use the nominal factor marked for the lens or adapter.

Square-pixel resolution convention

Delivery crop

Export rounding

Everything runs in your browser. No footage or entered production values are uploaded or tracked.

Desqueeze results

Native desqueezed aspect ratio —

Export desqueezed canvas—

Exact nominal canvas—

Recorded raster ratio—

Geometry correction—

Delivery crop resolution—

Image area retained—

Crop analysis Enter valid footage dimensions to calculate.

Preview

How to use the anamorphic desqueeze calculator

Enter the pixel width and height stored in the camera file. Do not enter dimensions from an already-desqueezed export.
Select the optical squeeze factor. Keep 1.33× and exact 4:3 separate when the distinction matters.
Choose how to express the corrected image as square pixels: expand width, or preserve width and reduce height.
Optionally choose a delivery aspect ratio. The calculator applies a centred crop and reports the crop in both desqueezed-canvas and recorded-source coordinates.
Use whole- or even-pixel rounding for an export plan. Exact decimal results remain available in the report.

A monitor desqueeze may correct only the display without creating a new raster. The calculated square-pixel dimensions are therefore a planning convention, not proof that a camera or editor will physically resample the clip to that size.

Desqueeze and crop formulas

Let W and H be the recorded pixel dimensions, and S be the anamorphic squeeze factor.

Recorded ratio = W ÷ H
Native desqueezed ratio = (W ÷ H) × S

Expand-width canvas: Wd = W × S; Hd = H
Preserve-width canvas: Wd = W; Hd = H ÷ S

For a target delivery ratio T, the calculator keeps the largest centred rectangle that fits inside the desqueezed canvas. If the native ratio is wider than T, it trims the left and right. If the native ratio is narrower than T, it trims the top and bottom.

If Wd ÷ Hd > T: crop width = Hd × T
If Wd ÷ Hd < T: crop height = Wd ÷ T
Area retained = crop area ÷ desqueezed canvas area × 100%

Common anamorphic combinations

Recorded shape	Squeeze	Native result	Practical note
6:5	2×	2.40:1	Direct mathematical match for 2.40:1.
4:3	1.8×	2.40:1	Direct mathematical match for 2.40:1.
4:3	2×	2.667:1	Needs a horizontal crop for 2.39:1 or 2.40:1 delivery.
3:2	1.6×	2.40:1	Direct mathematical match for 2.40:1.
16:9	1.33×	2.364:1	Slightly narrower than 2.39:1; reaching 2.39 requires a small vertical crop.
16:9	1.5×	2.667:1	Needs a horizontal crop for conventional scope delivery.

Ratios use the stated nominal squeeze exactly. Lens behaviour, camera metadata, and software presets may use slightly different effective values.

Assumptions and production limits

This calculator models a uniform horizontal squeeze and a centred geometric crop. It does not inspect lens distortion, focus-dependent squeeze, anamorphic mumps, stabilisation offsets, sensor active-area metadata, non-square source pixels, rotation, or an off-centre framing choice. Some lenses change effective squeeze at close focus, so test a known circle or square when pixel-accurate VFX, matchmove, or final delivery geometry matters.

Rounding a nominal canvas or crop to whole pixels can alter the ratio by a tiny amount. An NLE may instead preserve the exact transform internally and only quantise at export. Confirm the delivery raster, codec alignment, and pixel-aspect metadata in the finishing application.

References

ARRI: Why 6:5 for 2× anamorphic? — explains how 2.39:1 is squeezed to about 6:5 on the sensor.
Blackmagic URSA Cine Manual — provides a table of recorded formats, squeeze factors, and resulting desqueezed aspect ratios.

Anamorphic desqueeze FAQ

How do I calculate a desqueezed anamorphic aspect ratio?

Divide recorded width by recorded height, then multiply by the squeeze factor. For example, 6:5 is 1.2:1; multiplied by 2× it becomes 2.4:1.

Should I multiply width or divide height to desqueeze?

Either is geometrically valid. Multiplying width creates a wider square-pixel canvas; dividing height preserves the recorded width. Both produce the same corrected display ratio.

Does a 1.33× lens on 16:9 make exactly 2.39:1?

No. Using 1.33 exactly gives about 2.364:1. Even an exact 4:3 factor gives about 2.370:1, so a small vertical crop is required for 2.39:1.

Why can the exact desqueezed width be fractional?

Multiplying an integer raster width by a decimal squeeze factor can produce a fraction. A square-pixel export must round or scale that nominal result, while a display transform can retain the ratio internally.

Is the marked lens squeeze always exact?

Not necessarily. The effective squeeze of some lenses changes with focus distance. Use the marked factor for planning, then check critical material against a known geometric reference.

Does this tool upload my footage or inputs?

No. It calculates locally from the numbers entered and never requests a media file or sends production values to a backend.