MVLscope / Microscopy conceptsAll laboratories ↗

CONCEPT 01 · 8–10 MINUTES

Bigger isn't always clearer.

Magnification versus resolution

Follow the light

3D optical cutaway

Preparing the optical bench…

The objective collects light from the two points. A wider collection cone produces a narrower diffraction pattern.

What the detector sees

Ideal fluorescence image
PAIR / 300 nmDISPLAY 1×
500 nm
Below Rayleigh reference793 nmRayleigh reference distance

LOOK THROUGH THE CENTRE

One broad peak, or two?

The line profile uses specimen distances. Display zoom does not change this curve.

Normalized intensity · distance from pair centre (nm)

Model, assumptions & sources

Incoherent widefield fluorescence. An ideal scalar model of two equally bright point emitters, a circular pupil, monochromatic emission and perfect focus. Their Airy intensities add. The reference is d = 0.61 λ / NA; it is a useful convention, not a hard visibility boundary.

The numerical-aperture slider represents an ideal pupil stop. Correct immersion is assumed for each objective. The display enlarges a fixed, finely sampled 384 × 384 teaching image. It does not simulate a specific camera, confocal pinhole, aberrations, noise, bleaching or finite emitter size. The scalar approximation is simplified at high NA. Images are independently normalized; do not compare brightness or photon counts. The 3D optical path and emitter spacing are enlarged schematics, not a lens prescription.

Nikon MicroscopyU · Resolution ↗
Evident · Airy disk and numerical aperture ↗