Magnifiers

Light Magnifiers

Hand Lens or Loupe

• Handy, portable magnifier for viewing objects in nature at a slightly increased magnification

• Hand lenses give a three-dimensional view of objects

• Most provide a magnification 2x-10x, although some are 20x or 30x

  • The higher the magnification, the more steady your had needs to be!

• Image through the lens is not inverted; it is a direct image

Dissecting or Stereo Microscope

• Desktop microscope for viewing objects with higher magnification than a hand lens, but without the preparation of a compound scope

  • Stereoscopes are good for viewing the microscopic details of natural objects such as buds on twigs, minerals in rocks, details on invertebrates, etc.

• Stereo microscopes provide three-dimensional viewing of objects

• Most of these scopes provide magnification 10x-30x, but some can be up to 200x

  • Magnification is achieved through two different lenses: the eyepiece (usually 10x), and the objective lenses (e.g. 1x, 3x, or 20x lenses which would result in 10x, 30x, or 200x total magnification, respectively.

• These scopes need an external source of light, but the object does not need to be translucent

• Image through the lens is not inverted; it is a direct image

Compound Microscope

• Desktop microscope for viewing objects with higher magnification than a stereo microscope, but requires preparation of the material so that it is thin and translucent

  • Compound microscopes are good for viewing the microscopic, internal details of organisms, such as tissues, and cells

• The compound microscope provides two-dimensional viewing, due to the narrow focal range with high magnification

• Compound scopes can magnify material 40x-1,000x.

  • Magnification is achieved through two different lenses: the eyepiece (usually 10x), and the objective lenses (e.g. 4x, 10x, 40x, or 100x lens which would result in 40x, 100x, 400x, or 1,000x total magnification.

  • The 100x lens is called the "oil immersion lens", and requires a drop of immersion oil on the coverslip to achieve proper optics. The 100x lens should never be employed unless immersion oil is used

• The material must be thin-sliced by a razor blade or microtome in order to make it translucent

  • The work of thin-slicing can be avoided by using prepared slides.

  • Hand-made slides should use a coverslip to flatten specimen for viewing and protect the objective lenses

• The compound scope shines light up through the specimen and into the objective lenses

• The image through the lens is inverted; moving specimen on the stage to the right will result in the image appearing to go left.