Enter the focal length (mm) and the crop factor into the Calculator. The calculator will evaluate the Effective Focal Length.
Effective Focal Length Formula
EFL = FL * CF
Variables:
- EFL is the Effective Focal Length (mm)
- FL is the focal length (mm)
- CF is the crop factor
To calculate Effective Focal Length, multiply the focal length by the crop factor.
How to Calculate Effective Focal Length?
The following steps outline how to calculate the Effective Focal Length.
- First, determine the focal length (mm).
- Next, determine the crop factor.
- Next, gather the formula from above = EFL = FL * CF.
- Finally, calculate the Effective Focal Length.
- After inserting the variables and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
focal length (mm) = 50
crop factor = 1.25
FAQs
What is the significance of the crop factor in photography?
The crop factor is a crucial concept in photography that relates to the size of a camera’s image sensor compared to a full-frame sensor (35mm film equivalent). It affects the field of view and apparent magnification of lenses used on the camera. A higher crop factor means a narrower field of view and greater magnification for a given focal length.
How does the Effective Focal Length (EFL) impact the composition of a photograph?
The Effective Focal Length (EFL) impacts the composition by altering the angle of view and magnification of the scene captured. It essentially determines how ‘zoomed in’ your photos will appear. Understanding EFL helps photographers choose the right lens to achieve the desired composition and perspective.
Can the Effective Focal Length be calculated for any camera and lens combination?
Yes, the Effective Focal Length can be calculated for any camera and lens combination as long as you know the actual focal length of the lens and the crop factor of the camera’s sensor. This calculation helps in understanding how a lens will perform on different camera bodies.
Why is it important to calculate the Effective Focal Length before a photo shoot?
Calculating the Effective Focal Length before a photo shoot is important for planning and visualizing the shots. It helps photographers select the appropriate lens to achieve the desired field of view or to match a particular composition style, ensuring that the final images meet their creative vision.
