Microscope Lab

Robert Hooke (1635-1703) made early compound microscope.

Antony van Leeuwenhoek (1632-1723): made simple lenses, but could observe 200X.

Nikon YST-2 compound microscope (main campus)

Nikon Alphaphot-2 compound microscope (main campus, IC 3B)

Leica CME compound microscope (Naperville campus)

Resolution of objective = Refractive Index * wavelength / Numerical Aperture
Resolution decreases (can see finer detail) if N.A. increases.

Depth of field: Z = (2 * R.I. * wavelength)/N.A.²
Z decreases as N.A. increases: Calico Pennant

Magnification (apparent size at 25 cm) decreases with focal length of lens: m = 250mm / focal length.

Total magnification of a compound microscope = eyepiece power x objective power:

Eyepiece power: if focal length = 25 mm:

magnification

Objective power:
lens power N.A.^* color

Scanning power 4x 0.10 red

Low power 10x 0.25 yellow

High power 40x 0.65 blue

Immersion oil 100x 1.25 white

^*Air has R.I.=0.61, Oil has R.I.=1.50

lens	power	N.A.^*	color
Scanning power	4x	0.10	red
Low power	10x	0.25	yellow
High power	40x	0.65	blue
Immersion oil	100x	1.25	white

Estimating width of field.