| Objective Numerical Aperture
(where n = refractive index, u = half objective acceptance angle) |
NA = n(sinu) |
| Resolution - brighfield
(where λ = wavelength - 0.55µm standard, NAo =
objective NA, NAc = condenser NA ) |
 |
| Resolution - darkfield
(where λ = wavelength - 0.55µm standard, NAo =
objective NA, NAc = condenser NA ) |
|
| Single lens magnification
(where f = focal length in mm) |
|
| Objective magnification - finite tube length
(where OTL = optical tube length, fo
- objective focal length) |
|
| Objective magnification - infinity corrected
(where f∞ = focal length of standard
infinity tube lens, fo = objective focal length) NB
Standard infinty tube lens focal lengths are Leica & Nikon = 200mm,
Olympus = 180mm, Zeiss = 160mm |
|
| Eyepiece magnification (where fe
= focal length of eyepiece in mm) |
|
| Microscope magnification |
Mag = objective magnification x eyepiece
magnification |
| Maximum useful visual magnification |
Magmax =
1000 x NA |
| Depth of focus (consider
wavelength λ = 0.55) |
 
|
| Visual field of view (where FN
= eyepiece field of view number, Magobj
= objective magnification) |
|
| Image intensity (for epi-fluorescence
substitute (NA)4 ) |
|
