Introduction
The Camera Sensor Crop Calculator converts a lens focal length from one sensor format to its equivalent on another sensor format. You select your actual sensor size, enter the lens focal length, and choose the target format you want to compare against. The tool outputs the equivalent focal length, crop factor, and the resulting field of view change. This is the simplest and fastest way to answer the question: if I use this lens on this camera, what framing will I get compared to full frame or another system I am familiar with?
What This Tool Calculates
Every camera sensor has a different size, and that size fundamentally changes how a lens frames a scene. A 35mm lens on a Micro Four Thirds sensor frames like a 70mm lens on full frame. Without this calculation, a cinematographer who normally works on full frame would select entirely wrong lenses when moving to a Super 35 or smaller sensor camera. The crop factor also affects depth of field characteristics and the perceived compression of the image, making it essential for visual consistency when matching cameras or when a director of photography needs to achieve a specific look they have previously created on a different format.
The Formula and How It Works
Crop factor equals the reference sensor diagonal divided by the actual sensor diagonal. For full-frame reference (36mm x 24mm sensor, 43.27mm diagonal), a Super 35 sensor (approximately 24.89mm x 18.66mm, depending on the specific camera) has a crop factor of approximately 1.39x. The equivalent focal length is the actual focal length multiplied by this crop factor. A 35mm lens on Super 35 becomes approximately 35 x 1.39 = 48.65mm equivalent on full frame.
Real-World Examples
How to Use This Calculator
Select your camera's sensor format from the dropdown. Enter the focal length of the lens you are using or considering. The calculator instantly displays the crop factor for your sensor and the equivalent focal length on full frame. You can also select a different reference format if you want to compare against Super 35 or another standard rather than full frame.
Tips from Working Professionals
| Detail | Value |
|---|---|
| When discussing focal lengths with directors, always clarify which format you are referencing. | |
| Saying '50mm' without specifying the sensor creates confusion, since a 50mm looks very different on Super 35 versus full frame versus large format. | |
| Many cinematographers use full-frame equivalent as their common language and convert from there to whatever system they are actually shooting on. | |
| This calculator makes that conversion instant.. |
Pro Tips and Common Mistakes
Pro Tips
- Cinematographers, camera assistants, and directors who work across multiple camera systems.
- Rental coordinators helping clients build lens packages.
- Film students learning to think in terms of field of view rather than memorizing focal length numbers for a single format..
Common Mistakes
- Does crop factor change the actual focal length of the lens? No.
- The lens is optically identical regardless of the sensor behind it.
- Crop factor describes the change in field of view, not the physical properties of the lens.
Frequently Asked Questions
What is the crop factor of the ARRI Alexa 35?
The Alexa 35 has a Super 35 sensor with an approximate crop factor of 1.39x relative to full frame, though this varies slightly depending on the recording mode.
Can I use this for anamorphic lenses?
For the vertical framing, yes. For horizontal framing, you need to account for the anamorphic squeeze factor separately.
Start Calculating
This tool supports all major cinema sensor formats with accurate manufacturer dimensions rather than rounded approximations. It is designed for motion picture work with cinema-specific formats like Super 35, Super 16, and large format sensors that many photography-focused calculators omit.
