Compare calculators

Both calculators run independently — change the inputs on either side to compare results.

Diffraction Limit Calculator

Calculate the smallest resolvable spot or feature that an optical system can distinguish, based on wavelength and aperture. Use it when designing cameras, telescopes, or microscopes where resolution is critical.

Wavelength (nm)

Aperture Diameter (mm)

Focal Length (mm)

Diffraction Criterion

Fill in the required fields to see your result.

Optics

Lens Focal Length Calculator

Compute the focal length of any thick or thin lens from its refractive index, surface curvatures, and center thickness using the lensmaker's equation. Essential for optical designers, physics students, and DIY telescope builders.

Refractive Index of Lens Material

Radius of First Surface (cm)

Radius of Second Surface (cm)

Lens Thickness (cm)

Fill in the required fields to see your result.

Key differences

	Diffraction Limit Calculator	Lens Focal Length Calculator
Category	Optics	Optics
Inputs required	4	4
Result	Angular Resolution (μrad)	Focal Length (cm)
What it does	Calculate the smallest resolvable spot or feature that an optical system can distinguish, based on wavelength and aperture. Use it when designing cameras, telescopes, or microscopes where resolution is critical.	Compute the focal length of any thick or thin lens from its refractive index, surface curvatures, and center thickness using the lensmaker's equation. Essential for optical designers, physics students, and DIY telescope builders.