Bright field microscopy is the most commonly used technique where light passes through or reflects off a specimen. Biologists have used counterstaining for over 100 years to help differentiate tissues and organelles. The light path includes a light source, condenser lens to focus light, objective lens to collect and magnify the image, and oculars or camera to view the sample. It is mainly used for viewing stained specimens, pathological exams, blood tests, and inspections. Dark field microscopy uses oblique illumination to reveal fine detail, especially in bacteria. It illuminates specimens diagonally and observes light scattering in a darker field of view. It is useful for microbiology imaging and detecting scratches but lacks shading information.

1. BRIGHT FIELD MICROSCOPE
DONE BY
N.IRFANA NABEES

2. BRIGHT FIELD
MICROSCCOPY
• Most commonly used microscopy imaging
technique is bright field microscopy , where
light is either passed through or reflected off a
specimen
• Biologists and histologists have used counter
staining for over one hundred years; and this
helps to differentiate the various tissues and
organelles that can be found in a variety of
subjects that would otherwise be rendered
invisible.

3. LIGHT PATH
The light path therefore consists of
• A trans illumination light source, commonly a
halogen lamp in the microscope stand
• A condenser lens, which focuses light from the
light source into the sample
• An objective lens, which collects light from the
sample and magnifies the image
• Oculars and/or camera to view the sample

5. MAIN USES
• Viewing stained specimens
• Pathological exams
• Blood tests
• Water inspections
• Liquid crystal board inspections

6. PICTURES OF BRIGHT FIELD
MICROSCOPE

7. DARK FIELD MICROSCOPE

8. DARK FIELD
MICROSCOPY• A special condenser lens is used to illuminate
the specimens diagonally, then observe light
scattering off it.
• The field of view is darker than bright field
microscopy because illumination light does
not enter objective lens
• Oblique illumination is used to increase the
visibility of specimens
• Useful in revealing very fine detail especially
bacteria

9. DRAWBACK
S• Dark field is only black and white and is
missing information from the shading ability
of phase contrast
• For serious dark field work, one needs to use a
dedicated dark field condensor

11. MAIN USES
• Microbiological imaging
• Blood tests
• Detecting microscopic scratches or
irregularities

12. PICTURES OF DARK FIELD
MICCROSCOPE