1. What is the Focal Length Formula?

The focal length formula calculates the optimal lens focal length for a projector based on the sensor size, working distance (throw distance), and desired field of view. This is essential for proper image projection and sizing.

2. How Does the Calculator Work?

The calculator uses the focal length formula:

Where:

• \( Sensor\ Size \) — Size of the projector's imaging sensor (mm)
• \( Working\ Distance \) — Distance from projector to screen (mm)
• \( Field\ of\ View \) — Desired projection width (mm)

Explanation: The formula determines the lens focal length needed to achieve a specific projection size at a given distance.

3. Importance of Focal Length Calculation

Details: Correct focal length ensures proper image size and clarity for your projection setup. It's crucial for both home theater and professional installations.

4. Using the Calculator

Tips: Enter all dimensions in millimeters. Ensure accurate measurements of your actual setup for best results. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What if I know the focal length but need to calculate throw distance?
A: Rearrange the formula: Working Distance = (Focal Length × Field of View) / Sensor Size

Q2: How does sensor size affect focal length?
A: Larger sensors require longer focal lengths to achieve the same field of view at a given distance.

Q3: What are typical focal lengths for home projectors?
A: Most home theater projectors have focal lengths between 15mm and 50mm, depending on the throw ratio.

Q4: Can I use this for short-throw projectors?
A: Yes, but ultra-short-throw projectors use complex optical designs that may not follow this simple formula exactly.

Q5: How precise does this calculation need to be?
A: For most installations, rounding to the nearest available lens focal length is acceptable, as projectors often have some zoom capability.