FStop Calculator Focal Length Aperture Diameter and FStop

This calculator helps you calculate the FStop value based on the focal length and aperture diameter of a camera lens.

Input Parameters

Calculation Results

Calculation Results

FStop (F-number): -

Calculation Formula

FStop (F-number) = Focal Length / Aperture Diameter

Where:
FStop (F-number) - The aperture's f-number, which indicates the size of the aperture opening relative to the focal length
Focal Length - The distance from the lens's optical center to the image sensor
Aperture Diameter - The diameter of the aperture opening in the lens

FStop Calculator Focal Length Aperture Diameter and FStop Calculator Usage Guide

Learn how to use the FStop Calculator and understand its working principles

How to Use the Calculator

  1. Enter the Focal Length of your lens in millimeters (mm). This is typically printed on the lens itself.
  2. Enter the Aperture Diameter of your lens in millimeters (mm). This value can often be calculated if you know the FStop value and focal length (FStop = Focal Length / Aperture Diameter).
  3. Click the Calculate button to compute the FStop value.
  4. The calculator will display the calculated FStop value based on your inputs.

Understanding FStop

FStop (or F-number) is a ratio that describes the aperture size relative to the focal length of a lens. It affects both the amount of light that reaches the camera sensor and the depth of field in your image.

The formula used in this calculator is:

FStop = Focal Length / Aperture Diameter

For example, if you have a 50mm lens with an aperture diameter of 21.3mm, the FStop would be calculated as:

FStop = 50mm / 21.3mm ≈ 2.35

Practical Applications

  • Photography: Understanding how changing the FStop affects your exposure and depth of field
  • Camera lens selection: Comparing lenses with different FStop capabilities
  • Scientific imaging: Precise control over light intensity and depth of field