Lens Sign Convention
What is Lens?
A lens is a piece of transparent material, typically shaped like a circle, that uses refraction to focus light rays.
What is Lens Sign Convention Table?
Table for lens sign convention is given below:
Parameter Sign Convention Object Distance (u) Positive in front of the lens (real object) Negative behind the lens (virtual object) Image Distance (v) Positive on the opposite side of the incident light (real image) Negative on the same side as the incident light (virtual image) Focal Length (f) Positive for converging lens (convex lens) Negative for diverging lens (concave lens)
How to Apply Lens Sign Convention in Calculations?
Here’s how you can apply the lens sign convention in calculations,
- Identify the type of lens
- Determine the sign of focal length (f)
- Assign signs to Object Distance (u) and Image Distance (v).
Is v positive or negative in a convex lens?
Image distances (v) in a convex mirror are always positive since the image is always created behind the mirror.
Is v negative in concave lens?
For a concave lens, the image distance (V) is always negative. This is due to the fact that a concave lens’s focal length (f) is always negative.
Lens Sign Convention
A lens in optics is a transparent device with curved surfaces that refract light. It can be converging or diverging based on its shape. The lens sign convention, or Cartesian sign convention, helps determine the nature, size, and position of images formed by lenses accurately. It clarifies the positive and negative signs for object and image distances, focal lengths, and magnifications, crucial for optical calculations and predictions.
Table of Content
- What is the Lens Sign Convention?
- Basics of Lens Sign Convention
- Cartesian Sign Convention
- Sign Conventions in Different Lenses
- Lens Maker’s formula
- Conclusion: Lens Sign Convention