"They have also a shorter focus for red, and a longer one for blue, and thus magnify the red image more than the blue; and as the objective gives a large blue and small red image, the two cancel one another and a colourless image is produced." —Encyclopaedia Britannica, 1910

Huyegenian Eyepiece Diagram Showing Lens Refraction

"They have also a shorter focus for red, and a longer one for blue, and thus magnify the red image more…

"If the real image produced by the objective coincides with the collective lens, only the inclination of the principal rays is altered. The lens nearer to the eye is distant from it about its focal length. The eye—lens converts diverging pencils into parallels. Both lenses together form the exit pupil of the objective behind the eye—lens." —Encyclopaedia Britannica, 1910

Ramsden Eyepiece Lens Refraction Diagram

"If the real image produced by the objective coincides with the collective lens, only the inclination…

A Baker demonstration light microscope illustrating the different parts of the microscope. The eyepiece is adjusted at knob F. The mirror J reflects light from a light source to shine light through the sample.

Baker Demonstration Light Microscope with Mirror Reflecting Light Source

A Baker demonstration light microscope illustrating the different parts of the microscope. The eyepiece…

An illustration of entocentric transmission of a compound microscope. The series of light refracted by the lens causes a projection to make near objects appear larger, and farther objects smaller.

Entocentric Transmission in Compound Microscope Appear Images Larger or Smaller

An illustration of entocentric transmission of a compound microscope. The series of light refracted…

A Greenough's binocular light microscope. The microscope has two eyepieces to view the sample with both eyes. The mirror is used to provide a light source for the microscope by reflecting light.

Greenough's Binocular Light Compound Microscope with Mirror Reflecting Light Source

A Greenough's binocular light microscope. The microscope has two eyepieces to view the sample with both…

"The intersection of the principal rays lies in front of the object, and consequently objects in front of the plane focused for will be projected on E magnified and the objects lying behind it diminished ("hypercentric" transmission). It produces a perspective representation entirely opposed to ordinary vision." —Encyclopaedia Britannica, 1910

Hypercentric Transmission in Microscopic Objective

"The intersection of the principal rays lies in front of the object, and consequently objects in front…

A petrographic light microscope used to identify thin layered rocks and minerals. The microscope have two polarizer filter beneath the sample, with circular rotating stage.

Petrographical Light Microscope with Mirror and Eyepieces

A petrographic light microscope used to identify thin layered rocks and minerals. The microscope have…

"The image produced by a microscope formed of two positive systems is inverted, the objective L1 tracing from the object OO1 a real inverted image O'O'1, and the eyepiece L2L2 maintaining this arrangement." —Encyclopaedia Britannica, 1910

Ray Transmission in Compound Microscope with a Positive Ocular

"The image produced by a microscope formed of two positive systems is inverted, the objective L1 tracing…

An illustration of a compound microscope that produces upright image using negative eyepiece. The image is focused onto a concave lens, instead of convex lens, to diverging light.

Ray Transmission in Compound Microscope with a Negative Eyepiece

An illustration of a compound microscope that produces upright image using negative eyepiece. The image…

A light reflection diagram of a light microscope using a mirror. The mirror is used in a microscope to provide light for the sample. The light source hits the mirror, then gets reflected onto the small condenser lens on the stage.

Microscope Mirror Illumination by Light Reflection

A light reflection diagram of a light microscope using a mirror. The mirror is used in a microscope…

Illustration showing Abbe illuminating apparatus with condenser. The mirror, m, reflects light from the light source to provide light for viewing the specimen. The reflected light is passed through the condenser then onto the specimen.

Abbe Microscope Mirror Illumination by Light Reflection with Condenser

Illustration showing Abbe illuminating apparatus with condenser. The mirror, m, reflects light from…