What is the function of microscope?

2. Forensic science Instrumentation
Techniques-
Introduction to Microscope
Written by-Yukta Guglot Secretary of AFRS
Presented by- Ritoza Das, Volunteer of AFRS

3. Content:
• Anatomy of Microscope
• Significance of Microscope

5. Parts of Microscope:
1. The eyepiece or Ocular:
The specimen is viewed through the eye-piece .Typically, standard
eyepieces have a magnifying power of 10x. Optional eyepieces of
varying powers are available, typically from 5x-30x.
2. Eyepiece Tube:
It holds the eyepieces in place above the objective lens. Binocular
microscope heads typically incorporate a diopter adjustment ring that
allows for the possible inconsistencies of our eyesight in one or both
eyes.

6. 3. Objective lense:
These are the primary optical lenses on a microscope. They
almost always consist of 4x, 10x, 40x and 100x powers. When
coupled with a 10x (most common) eyepiece lens, total
magnification is 40x (4x times 10x), 100x , 400x and 1000x and
typically, include, three, four or five on lens on most microscopes.
Objectives can be forward or rear-facing.
Parts of Microscope:

7. 4. Nose piece:
It is also known as the revolving turret. It holds the
objective lenses. It is movable hence it cal revolve the
objective lenses depending on the magnification power of
the lens.
5. The Adjustment knobs or Coarse:
These are knobs that are used to focus the microscope.
There are two types of adjustment knobs i.e fine
adjustment knobs and the coarse adjustment knobs.
Parts of Microscope:

8. 6. Stage and stage clips:
This is the section on which the specimen is placed for viewing. They
have stage clips hold the specimen slides in place. The most common
stage is a mechanical stage, which allows the control of the slides by
moving the slides using the mechanical knobs on the stage instead of
moving it manually.
Stage Clips are used when there is no mechanical stage. The viewer is
required to move the slide manually to view different sections of the
specimen.
Parts of Microscope:

9. 7. Iris Diaphragm:
It controls the amount of light reaching the specimen. It is located
above the condenser and below the stage. Most high quality
microscopes include an Abbe condenser with an iris diaphragm.
Combined, they control both the focus and quantity of light
applied to the specimen.
8. Aperture:
This is a hole on the microscope stage, through which the transmitted
light from the source reaches the stage.
Parts of Microscope:

10. 9. Microscopic illuminator:
This is the microscopes light source, located at the base. It is used
instead of a mirror. It captures light from an external source of a low
voltage of about 100v.
10. Condenser:
The condenser lens works with the diaphragm to focus the intensity of
the light source onto the slide containing the specimen. These parts are
located under the microscope stage.
Parts of Microscope:

11. Significance of Microscope in Forensic:
Microscopic analysis and examination of evidence provide valuable results in crime
scene or scene of crime investigation.
The following evidence is examined under a microscope.
1. Gunshot residue analysis
2. Firearms identification – bullet marking comparison
3. Investigation of gemstones and jewellery
4. Examination of paint particles and fibers
5. Handwriting and print examination or forgery examination.
6. Counterfeit bank notes
7. Trace comparison
8. Biological/Serological evidence examination.

12. Thankyou