The document is an assignment report on the Video Spectral Comparator (VSC), an integrated system used for the analysis and authentication of various documents, particularly in forensic science and immigration. It details the principle, features, applications, advantages, and disadvantages of the VSC, highlighting its non-destructive capabilities in revealing security features and detecting alterations in documents. A notable case demonstrates its effectiveness in recovering previously indecipherable evidence, emphasizing its value in forensic investigations.

1. Dr. A.P.J. Abdul Kalam Institute of Forensic Science
and Criminology
Submitted To-
Dr. Anu Singla
BU, JHANSI
Submitted By-
Shailesh Chaubey
B.Sc Forensics
IInd Year
Session:- 2022-23
Assignment Report
On
VIDEO SPECTRAL COMPARATOR

2. VSC
VIDEO SPECTRAL COMPARATOR
An instrument to see the artefacts beneath the surface

3. CONTENTS
• Introduction
• Principle
• Features
• Light sources and uses
• Applications
• Advantages
• Disadvantages
• A case on vsc
• References

4. INTRODUCTION
It is designed to satisfy the demands of immigration authorities , government agencies and forensic
science labs . the VSC includes advanced characterstics for the examination,comparison and
authentication of documents including passports and travel records , official letters and breeder
documents , banknotes and cheques , works of art and valuable artifacts through the detection of
imperfections.
Video spectral comparator comprises of the following :-
• Laser – induced breakdown spectrometer
• Computer
• Monitor
VSC is an integrated composite system comprising of cameras , various light sources which include ir,
lasers , uv etc. And filters that assist in the comparison of questioned document.

5. PRINCIPLE
VSC works on the basic principle of light
When light is directed towards an object, any of the one of five things usually occurs depending on the
emitted wavelength and the composition of the object :–
1. Reflection
2. Absorption
3. Reflection and absorption
4. Transmission
5. Luminescence
The Video Spectral Comparator (VSC) uses filter to vary the light bombarding the document . the
document is viewed through a camera and computer monitor . As the wavelength of the light is varied
, the picture changes.

6. LIGHT SOURCES AND THEIR USES
Incandescent
filament lamps
Narrow-band
illumination
Coaxial light Spectrum screen
• Range : 400-
1000nm
• Function of flood,
transmitted , spot
and side lighting.
• Trigger fluorescence
• IR region above
800nm & lacks
visible light
• Perpendicularly on
the document
• Retro-reflective
features in security
documents
• This feature hidden
under normal light
but exposed when
the incident light is
exactly coaxial to
the angle of view.
• Micro spectrometry
with resolution of
up to 9nm
• Shows chromaticity
chart and a
spectral graph after
a spectrum has
been recorded
• In special graphs ,
one can read the
plots of intensity
VS the wavelength
from 400-1000nm.

7. FEATURES
VSC is a general workstation and casework management system for document
examiners featuring the following-
HI-FI IMAGING
TECHNOLOGY
An optical system that reduces
spatial distortions and chromatic
aberration throughout the entire
magnification range after
excellent image quality.
FULL RANGE
LIGHT SOURCE
It includes incident and
transmitted ultraviolet to
infrared plus high-intensity
illumination for the examination
of infrared fluorescence of inks.
GRAPHIC USER
INTERFACE
Innate, on screen control
method permits the operator to
operate the system more easily.

8. FEATURES
• High-resolution imaging system
• Multiple Laser Images (MLI) : MLI and changeable laser images can be viewed using the VSC’s
sidelights . Alternatively ,the VSC range of hologram imaging LED’S can be used giving great
versatility.
• VSC updated software is integrated with the document database system (with a single user-
license) that permits the operator to create their database of security documents .
• Keesing is a reference database of security documents i.e. passport ,id card, driving license of 180
countries , comprises images and data.
• Access to optional reference database enables comparisons with authentic security documents.

9. APPLICATIONS OF VSC
1. Reveal latent images and watermark : latent images and watermarks are a commonly used security feature on
banknotes worldwide.
2. A latent image is visible only when viewed at an acute angle under reflected light and the watermark is viewed
under transmitted light.
3. Anti strokes illuminator
4. Examining uv activated security features vsc is designed for the visual examination of questioned documents and
security documents.
5. It is used by immigration authorities and forensic labs.
6. It is effective on all types of passports and identity cards
7. It helps to detects alterations and counterfeits.

10. APPLICATIONS
1. Banks – with VSC each security feature of bank notes can be observed like ink, images, paper
gradient and security thread. It can be used to examine suspected fake cheques.
2. Enhancement of handwritings on charred documents.
3. Establishing the chronological order of intersecting printed strokes and writing pen strokes.
4. It provides documentary evidence for prosecutions.
5. Examination of documents under high magnification can quickly reveal evidence of tampering.
6. Government offices – examination of fake official documents fraudsters create fake certificates ,
notarized documents, license agreements , degree certificates , birth certificates etc. VSC can be
very useful to examine such documents and establish authenticity of it.

11. ADVANTAGES OF VSC
1. Convenient and comprehensive for the non-destructive analysis of ink and paper
2. Helps to detect differences between ink in terms of chemical formulation & it reveals writing
that has been added using a different ink.
3. Reveals altered or removed writing using variations in the way different inks respond to
different wavelengths of light.
4. Visualizes the security features printed into papers & allow quick examination of the
questioned document
5. “Foster & freeman” noted that non destructive vsc examination makes it possible to establish
the authenticity of an item, detect changes that have been made and to see beneath the surface
of an artifact revealing its history.

12. DISADVANTAGES
1. The results obtained by using the vsc are only indicative and not definite
because the machine only compares one set of data to another .
2. Furthermore, when using the vsc for examination , comparison can only be
done when the specimen comparison is available .
3. Used only for differentiating purpose and not for identification purpose.
4. The instrument is very costly.
5. Not possible to carry the machine at the crime scene.

13. A CASE ON VSC
Fluorescence is also used to detect deteriorated , obscure, indecipherable ,or
invisible evidence.
In one landmark case, the Miami-Dade police department crime laboratory was
able to recover a telephone number written on a murder victim’s palm.
The number could not be read with the naked eye or with magnification but it
fluoresced under the vsc.
When investigators went to the address to which the number was traced , the
murderer opened the door and confessed.

14. REFERENCES
VSC https://forensicfield.blog/video-spectral-comparator-vsc/
VSC
http://epgp.inflibnet.ac.in/epgpdata/uploads/epgp_content/S000016FS/P000695/M01151
2/ET/1516250916FSC_P8_M33_e-text.pdf
https://regulaforensics.com/en/products/advanced_verification/4307/
VSC CASE - https://www.fraud-magazine.com/article.aspx?id=4294967851

15. THANK YOU
END OF THE PPT