Anamorphic calculator
Pick a camera, its recording mode, a squeeze and a lens. You get the desqueezed aspect ratio, the angle the lens covers on the squeezed axis, and how much of the mode a 2.39 or other delivery frame keeps.
With JavaScript off this shows an ARRI ALEXA 35 in 3.3K 6:5 with a 2x squeeze on a 50mm, delivered at 2.39:1.
Gray: the whole mode, desqueezed. Yellow: the 2.39 frame.
ARRI ALEXA 35, 3.3K 6:5 is 20.22 × 16.95 mm. With a 2x squeeze it desqueezes to 2.39:1 and a 50mm lens sees 44.0° across. A 2.39 frame uses 20.22 × 16.92 mm of it, cropping the top and bottom, and sees 44.0° across.
On this page
What the squeeze does to the frame
An anamorphic lens squeezes the picture sideways onto the sensor. A 2x lens fits twice the horizontal view into the same width, and the picture is stretched back out in post. So the lens sees as wide as a spherical lens would on a sensor twice as wide, while the height stays the same. That is the whole calculation:
- desqueezed aspect = squeeze × width ÷ height
- horizontal angle = 2 × arctan(squeeze × width ÷ (2 × focal length))
- vertical angle = 2 × arctan(height ÷ (2 × focal length))
This is the rule Cutvey Viewfinder uses to draw an anamorphic frame over the phone's picture. The vertical angle is the one a squeeze leaves alone, which is why anamorphic shooters often talk about a 50mm "seeing like a 25mm across".
Picking the mode for the squeeze
A 2x lens wants a squarer mode. A 6:5 or 4:3 mode desqueezed at 2x lands close to 2.39:1, so very little of the sensor is thrown away. A 16:9 mode with a 2x lens desqueezes to about 3.55:1 and must lose its sides for a 2.39 delivery. Lighter squeezes (1.33x, 1.5x, 1.8x) suit wider modes. In the gear list 194 recording modes are flagged as made for anamorphic lenses, and 108 lens series carry a squeeze.
| Mode | Size | Squeeze | Desqueezed | 50mm across |
|---|---|---|---|---|
| ARRI ALEXA 35, 3.3K 6:5 | 20.22 × 16.95 mm | 1.5x | 1.79:1 | 33.7° |
| ARRI ALEXA 35, 3.3K 6:5 | 20.22 × 16.95 mm | 1.8x | 2.15:1 | 40.0° |
| ARRI ALEXA 35, 3.3K 6:5 | 20.22 × 16.95 mm | 2x | 2.39:1 | 44.0° |
| ARRI ALEXA Mini LF, 2.8K LF 1:1 | 23.76 × 23.76 mm | 1.5x | 1.5:1 | 39.2° |
| ARRI ALEXA Mini LF, 2.8K LF 1:1 | 23.76 × 23.76 mm | 1.8x | 1.8:1 | 46.3° |
| ARRI ALEXA Mini LF, 2.8K LF 1:1 | 23.76 × 23.76 mm | 2x | 2:1 | 50.8° |
| ARRI ALEXA 35, 3K 1:1 | 18.66 × 18.66 mm | 1.5x | 1.5:1 | 31.3° |
| ARRI ALEXA 35, 3K 1:1 | 18.66 × 18.66 mm | 1.8x | 1.8:1 | 37.1° |
| ARRI ALEXA 35, 3K 1:1 | 18.66 × 18.66 mm | 2x | 2:1 | 40.9° |
Computed from the recording mode sizes in the Cutvey Viewfinder gear list, counted November 2, 2026.
A worked example
Put a 2x anamorphic on an ARRI ALEXA 35 in 3.3K 6:5, which is 20.22 × 16.95 mm. Desqueezed it is 2.39:1, a hair narrower than 2.39, so a 2.39 delivery crops a little off the top and bottom and keeps 100 percent of the mode. A 50mm then sees 44.0° across the delivered frame and 19.2° top to bottom.
Swap to a 1.33x lens on the same camera's 4.6K 16:9 (27.99 × 15.75 mm): it desqueezes to 2.36:1, and the 2.39 frame keeps 99 percent of the mode, cropping the top and bottom.
Frame lines in the app
In Cutvey Viewfinder you set the squeeze with the lens series (or pick an anamorphic series from the list) and choose the delivery ratio as the aspect. The viewfinder draws the desqueezed frame and the 2.39 lines over the live picture, and you can add a second frame line, such as 1.85 inside 2.39, for a second delivery. On a camera turned on its side for vertical, the squeeze moves to the vertical axis. Depth of field in the app does not account for the squeeze.
Read anamorphic lenses explained, anamorphic lenses in the app and aspect ratios and frame lines.
Questions
Which squeezes can I enter?
The list has the common squeezes from 1.25x to 2x, and Another squeeze takes any value from 1.0 to 2.05, the same range the app accepts for a custom lens series.
What does Mode used mean?
The share of the recording mode's area that ends up inside the delivery frame. A high figure means little of the sensor is thrown away.
Does the squeeze change depth of field?
The optics do, but this page and the app work out depth of field for the taking lens's focal length and stop without a squeeze term. Treat it as a planning figure.
Related
See the frame before the camera arrives
Cutvey Viewfinder frames any camera, recording mode and lens on your iPhone or iPad. $19.99, once.