1. What is Microscope Resolution?

Microscope resolution refers to the ability of a microscope to distinguish two closely spaced objects as separate entities. It is a fundamental parameter that determines the level of detail visible through a microscope.

2. How Does the Resolution Formula Work?

The calculator uses the resolution formula:

Where:

• \( \lambda \) — Wavelength of light (nm)
• \( NA \) — Numerical aperture (unitless)
• 0.61 — Constant derived from the Rayleigh criterion

Explanation: The formula shows that resolution improves (decreases) with shorter wavelengths and higher numerical apertures. This is known as the Abbe diffraction limit.

3. Importance of Resolution Calculation

Details: Understanding and calculating resolution is crucial for selecting appropriate microscopy equipment, interpreting microscopic images, and determining the limitations of optical systems in various scientific and medical applications.

4. Using the Calculator

Tips: Enter the wavelength of light in nanometers and the numerical aperture value. Both values must be positive numbers. Typical visible light wavelengths range from 400-700nm, and numerical aperture values typically range from 0.1 to 1.4 for standard objectives.

5. Frequently Asked Questions (FAQ)

Q1: What is numerical aperture (NA)?
A: Numerical aperture is a dimensionless number that characterizes the range of angles over which the system can accept or emit light. It is determined by the formula NA = n × sin(θ), where n is the refractive index and θ is the half-angle of the maximum cone of light.

Q2: Why is the constant 0.61 used?
A: The constant 0.61 comes from the Rayleigh criterion, which defines the minimum separation at which two point sources can be distinguished. This value is derived from the properties of Airy disks formed by diffraction.

Q3: Can resolution be better than this formula predicts?
A: For conventional light microscopy, this represents the theoretical limit. However, super-resolution techniques like STED, PALM, and STORM can achieve resolutions beyond this diffraction limit.

Q4: How does immersion oil affect resolution?
A: Immersion oil has a higher refractive index than air (typically around 1.5), which allows for higher numerical apertures and thus better resolution.

Q5: Does this formula apply to electron microscopy?
A: No, electron microscopy uses different principles and formulas for resolution calculation, as electrons have much shorter wavelengths than visible light.