Anamorphic Calculator

An essential tool for cinematographers. This professional anamorphic calculator helps you determine the final de-squeezed aspect ratio, field of view (FOV), and equivalent focal lengths for your specific camera sensor and lens setup. Plan your shots with precision.

Final Aspect Ratio = (Sensor Width * Squeeze Factor) / Sensor Height

Aspect Ratio Comparison For Your Sensor (24.89mm x 18.66mm)

Squeeze Factor	Final Aspect Ratio	Common Use Case

What is an Anamorphic Calculator?

An anamorphic calculator is an essential digital tool for cinematographers, directors of photography, and camera assistants. Its primary function is to compute the final, de-squeezed aspect ratio of an image captured with an anamorphic lens. Anamorphic lenses optically compress an image horizontally by a specific ratio (the “squeeze factor”). This compressed image is then stretched out in post-production (a process called de-squeezing) to create a widescreen image. An anamorphic calculator removes the guesswork from this process, allowing filmmakers to precisely plan their shots and compositions.

Anyone using anamorphic lenses, from students to seasoned professionals, will benefit from using an anamorphic calculator. It helps in visualizing the final frame, choosing the right lens for a desired aspect ratio, and understanding the relationship between sensor size and the final image dimensions. A common misconception is that you can just multiply your camera’s aspect ratio by the squeeze factor. While this is a good starting point, a dedicated anamorphic calculator provides more critical data, such as the effective Field of View (FOV), which is crucial for creative decisions.

Anamorphic Calculator Formula and Mathematical Explanation

The core of any anamorphic calculator involves a few key formulas. The most fundamental calculation determines the final aspect ratio of the de-squeezed image. Understanding this helps in framing shots to protect for a specific final delivery format, such as 2.39:1 CinemaScope.

1. De-Squeezed Aspect Ratio: This is the most important output. The formula is:

Final Aspect Ratio = (Sensor Width × Squeeze Factor) / Sensor Height

2. Horizontal Field of View (FOV): This is arguably more important than aspect ratio for a cinematographer. It tells you how ‘wide’ your shot will be. Because an anamorphic lens squeezes the horizontal axis, it provides a wider horizontal field of view than a spherical lens of the same focal length. The equivalent spherical focal length for the horizontal FOV is calculated as:

Equivalent Horizontal Focal Length = Anamorphic Focal Length / Squeeze Factor

Then, the actual angle is calculated using trigonometry:

Horizontal FOV (°) = 2 × arctan(Sensor Width / (2 × Equivalent Horizontal Focal Length)) × (180 / π)

Variables Table

Variable	Meaning	Unit	Typical Range
Sensor Width	The physical width of the camera’s image sensor.	mm	17 – 36
Sensor Height	The physical height of the camera’s image sensor.	mm	9 – 24
Squeeze Factor	The horizontal compression ratio of the anamorphic lens.	x	1.3x – 2.0x
Focal Length	The stated focal length of the anamorphic lens.	mm	28 – 150

Practical Examples (Real-World Use Cases)

Example 1: Blackmagic Pocket Cinema Camera 4K with a 1.33x Lens

A filmmaker is using a BMPCC 4K, which has a sensor size of approximately 18.96mm x 10mm (a 16:9 ratio). They attach a 35mm Sirui 1.33x anamorphic lens.

• Inputs: Sensor Width = 18.96mm, Sensor Height = 10mm, Squeeze Factor = 1.33x, Focal Length = 35mm.
• Calculation: The de-squeezed aspect ratio is (18.96 * 1.33) / 10 = 2.52:1. This is wider than standard CinemaScope (2.39:1).
• Interpretation: The filmmaker knows they will have extra width to play with. They can either crop the sides in post-production to achieve a perfect 2.39:1 frame, or use the full 2.52:1 for a unique ultra-widescreen look. This anamorphic calculator would also show them the equivalent horizontal focal length is 35mm / 1.33 = 26.3mm, giving them a much wider field of view than a standard 35mm spherical lens.

Example 2: ARRI Alexa Mini with a 2x Lens

A high-end commercial is being shot on an ARRI Alexa Mini in its 4:3 2.8K mode (23.76mm x 17.82mm). The Director of Photography chooses a classic Cooke 50mm 2x anamorphic lens.

• Inputs: Sensor Width = 23.76mm, Sensor Height = 17.82mm, Squeeze Factor = 2.0x, Focal Length = 50mm.
• Calculation: The de-squeezed aspect ratio is (23.76 * 2.0) / 17.82 = 2.66:1.
• Interpretation: This combination is a classic cinematic setup. The 2.66:1 aspect ratio will be cropped slightly in post to the standard 2.39:1 delivery format. The anamorphic calculator reveals the powerful effect of the 2x squeeze: the 50mm lens provides the horizontal field of view of a 25mm spherical lens, creating an epic sense of scale, while maintaining the compressed perspective and shallow depth of field of a 50mm lens.

How to Use This Anamorphic Calculator

Using this anamorphic calculator is straightforward and designed to give you actionable insights in seconds.

1. Enter Sensor Dimensions: Input your camera’s sensor width and height in millimeters. You can find this in your camera’s technical specifications. This is the most critical step for an accurate calculation.
2. Select Squeeze Factor: Choose your lens’s squeeze factor from the dropdown list. This value is always printed on the lens barrel (e.g., 1.33x, 1.8x, 2x).
3. Input Focal Length: Enter the focal length of your anamorphic lens in millimeters (e.g., 50mm).
4. Read the Results: The calculator instantly updates. The primary result is your final de-squeezed aspect ratio. You also see key intermediate values like the de-squeezed width and, crucially, the Horizontal Field of View and its spherical equivalent.
5. Analyze the Chart and Table: Use the dynamic bar chart to visually compare the horizontal field of view against a spherical lens. The comparison table below shows how different squeeze factors would affect the aspect ratio on your specific camera sensor. This can help you decide if a different anamorphic calculator might be needed for a future project. For more details, see our lens guide.

Key Factors That Affect Anamorphic Results

The results from an anamorphic calculator are influenced by several interconnected factors. A change in one can significantly alter the final look and feel of your footage.

• Sensor Size & Aspect Ratio: This is the canvas. A taller sensor (like 4:3 or 6:5) is ideal for 2x anamorphic lenses, as it uses the full image circle and results in a classic widescreen aspect ratio. Using a wide 16:9 sensor with a 2x lens might result in an unusably wide aspect ratio.
• Lens Squeeze Factor: This is the most defining characteristic. A 1.33x squeeze on a 16:9 sensor gets you close to 2.39:1, making it a popular choice for budget-conscious filmmakers. A 2x squeeze provides the most dramatic anamorphic characteristics (oval bokeh, distinct flares) but requires taller sensors and more careful framing.
• Focal Length: Just like with spherical lenses, this determines your field of view and compression. However, with anamorphics, you get two distinct characteristics: the horizontal field of view of a wider lens and the vertical field of view and depth-of-field of the stated focal length. This “dual personality” is a key reason filmmakers use them.
• Post-Production Workflow: Your ability to de-squeeze and crop footage is vital. The anamorphic calculator helps you plan this. If your calculator shows a 2.66:1 result, you must know how you will crop to 2.39:1 in your editing software.
• Diopter Use: Anamorphic lenses often have a longer minimum focusing distance. Using diopters (close-up filters) can affect sharpness and distortion, which isn’t calculated here but is a practical consideration on set.
• Aperture (T-Stop): While not a direct input in this anamorphic calculator, your lens’s T-stop affects depth of field. The compressed perspective of anamorphic lenses already creates a shallower perceived depth of field, which is amplified at wider apertures. Understanding your aspect ratio calculator results is key.

Frequently Asked Questions (FAQ)

1. Why is my de-squeezed aspect ratio not exactly 2.39:1?

The final ratio is a pure calculation based on your sensor and lens. It’s very common for the raw result to be slightly different (e.g., 2.36:1 or 2.44:1). Filmmakers almost always apply a slight crop in post-production to perfectly match the desired cinematic aspect ratio, such as 2.39:1 or 2.40:1.

2. What does ‘Spherical Equivalent (Horiz. FOV)’ mean?

This is one of the most useful outputs of an anamorphic calculator. It tells you what focal length a regular (spherical) lens would need to be to match the horizontal field of view of your anamorphic setup. For example, a 50mm 2x anamorphic lens “sees” as wide as a 25mm spherical lens horizontally.

3. Can I use an anamorphic lens on any camera?

Technically, yes, but the results vary dramatically. The key is matching the lens squeeze to the sensor aspect ratio. A great anamorphic calculator helps you simulate this before you buy or rent gear. For a deeper dive, check out our cinematography tools.

4. What is ‘Open Gate’?

‘Open Gate’ refers to using the entire physical area of the camera’s sensor for recording, rather than a pre-cropped portion like 16:9. This is often a taller aspect ratio (e.g., 4:3 or 1.55:1) and is ideal for shooting anamorphic because it maximizes the vertical resolution.

5. Why is the bokeh oval-shaped with anamorphic lenses?

The cylindrical lens elements that squeeze the image horizontally also squeeze the out-of-focus highlights (bokeh). When the image is de-squeezed in post, the squeezed circles become tall ovals, a hallmark of the anamorphic look.

6. Does this anamorphic calculator account for lens breathing?

No, this calculator focuses on aspect ratio and field of view. Lens breathing (a change in focal length when focus is pulled) is a separate optical characteristic of a specific lens and is not part of this calculation.

7. How do I handle a custom squeeze factor?

While this calculator provides common options, some rare vintage lenses have unique squeeze factors. You would need a more advanced tool or manual calculation for those. For most modern lenses, the options provided here are sufficient. Explore our articles on camera sensor specs for more info.

8. Why is there a separate Field of View for horizontal and vertical?

Because an anamorphic lens only squeezes the image horizontally. The vertical properties remain unchanged. Therefore, a 50mm anamorphic lens has the horizontal FOV of a wider lens but the vertical FOV of a 50mm spherical lens.

Related Tools and Internal Resources

Expand your filmmaking knowledge and toolset with these related resources.

• Aspect Ratio Calculator: A general-purpose tool for calculating aspect ratios and resolutions for any video project.
• Field of View Calculator: Calculate the precise field of view for any spherical lens and camera combination.
• Lens Guide: A deep dive into how focal length, aperture, and sensor size interact to create your image.
• Choosing The Right Lens for Your Project: An article exploring the creative and technical decisions behind lens selection.
• Camera Sensor Specs Database: A detailed database of sensor sizes and resolutions for popular cinema and mirrorless cameras.
• De-Squeeze Guide: A step-by-step tutorial for de-squeezing anamorphic footage in popular editing software like DaVinci Resolve and Adobe Premiere Pro.