A digital imaging instrument manufactured by Foster + Freeman that employs combinations of light sources and filters to examine document evidence under various wavelengths of radiation ranging from ultraviolet to the infrared regions of the electromagnetic spectrum. VSC is a preferred tool as it supports non destructive examination of documents. VSC uses multiple parameters like IR, UV, and White light providing accurate results.

1. Video
Spectral
Comparator
Presented By,
Palash Mehar
M.Sc. Part-II Semester-III
Govt. Institute of Forensic Science, Nagpur.
Academic Year: 2020-2021

2. A digital imaging instrument manufactured by Foster + Freeman that employs combinations
of light sources and filters to examine document evidence under various wavelengths of
radiation ranging from ultraviolet to the infrared regions of the electromagnetic spectrum.
Video Spectral Comparator
(VSC)
VSC is a preferred tool as it supports non destructive examination of
documents. VSC uses multiple parameters like IR, UV, and White
light providing accurate results.
VSC8000 is the new version of VSC which is available for use
for the forensic and general purposes.

3. Construction
PC SystemMain Unit
Image Source: VSC 8000 foster+freeman

4. Construction
The main unit is a square box with 3 flaps.
The main unit has;
1) a high resolution CCD firewire colour camera with sensitivity
from 360 nm to 1100 nm,
2) different light sources (incandescent filament lamps, LED,
vapour discharge tube, flash tube etc),
3) optical filters as well as a translight panel.
The panel is situated in the centre of the document platen.
Underneath the panel are light sources which can illuminate the
document from below. The document platen in itself is 650 mm *
650 mm while the translight panel is 235 mm * 175 mm.
In the VSC there is also a high resolution grating spectrometer.
This can analyze light from a small region in the document.
As part of the VSC machinery is a 30” screen and a PC system
which is Windows based.Image : Inside the VSC main unit.
Source : Laboratory Instruments Manual

5. Video Spectral Comparator works in the basic principle of light.
When light directed towards an object any of the one of five things
usually occurs depending on the emitted wavelengths and the
composition of the object –
1. Reflection
2. Absorption
3. Reflection and Absorption
4. Transmission
5. Luminescence
Principle

6. Different Light Sources Used In VSC
1) Incandescent filament lamps
These have a range from 400 nm to 1000 nm and encompass visible and IR light.
2) LED lamps
Wavelength from 400 nm to 700 nm are used with coaxial lighting and diffracted
lighting.
3) Vapour discharge tubes
The VSC offers three ranges of UV light. This is with 365 nm (UV-A), 312 (UV-
B), 254 (UV-C) peak wavelength.
4) Flash tube
This lamp has a range of 850 nm to 1100 nm and it is used for the Anti-stokes
flash function.

7. VSC Equipment
•For close to 40-years, the Foster+Freeman Video Spectral
Comparator (VSC) has been an essential tool in the field of
Questioned Document Examination (QDE).
•Used by QDE professionals in some of the busiest and most
highly regarded forensic science facilities worldwide, each new
generation of VSC workstation has further increased our ability
to authenticate genuine items and to identify counterfeits and
falsified documents of an increasingly high quality.
Source:
https://fosterfreeman.clickmeeting.com/599836551/?r=AQtlZmL1ZQu8sRABJH5TIFOnHyIB
EKk8L255ozM1raW1ozINqUchqaxhpTW6sUjlZwNlAGDjBD

8. Source: https://fosterfreeman.clickmeeting.com/599836551/?r=AQtlZmL1ZQu8sRABJH5TIFOnHyIBEKk8L255ozM1raW1ozINqUchqaxhpTW6sUjlZwNlAGDjBD

9. New Examination Techniques

11. Advantages of Video Spectral Comparator
1) This method is a convenient and comprehensive method for the non-destructive
analysis of inks and papers.
2) It can help detect differences between inks in terms of chemical formulation
and it reveals writing that has been added using a different ink.
3) The method also reveals writing that has been altered or removed using the
variations in the way different inks respond to different wavelengths of light.
4) It visualises the security features printed into papers and allow quick
examination of the questioned document.
5) Foster and Freeman (nd) 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 artefact revealing its history.

12. Disadvantages of Video Spectral Comparator
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.
Furthermore, when using the VSC for examination, comparison can only
be done only when the specimen comparison is available.
2) This technique has been used only for differentiating purposes and not
for identification purposes.
3) The instrument is very costly.
4) It is not possible to carry the machine at the crime scene

13. Applications
 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.
 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.
It can detect alterations made to original documents.
 Airport:
Examination of passport and visa documents.
Examination of documents under high magnification can quickly reveal evidence of
tampering.

14. Applications
 Forensic Examination:
VSC is one the most used tool in questioned document analysis.
Objects such as currency, stamps, certificates, legal documents, artwork, and
identification cards can be examined with the help of Video Spectral Comparator.
 Enhancement of handwritings on charred documents.
 Establishing the chronological order of intersecting printed strokes
and writing pen strokes.
 VSC as a non-destructive technique for identification of blood.

15. REFERENCES
1. Laboratory Instruments (2016). Retrieved 20 September 2020, from http://subhasishchandra.com/wp-
content/uploads/2016/10/Laboratory-Instruments.pdf
2. User, S. VSC8000 Video Spectral Comparator for Document Examination. Retrieved 21 September 2020, from
https://www.fosterfreeman.com/document-examination-3/620-video-spectral-comparator-8000.html
3. Chourasiya S, Shaikh T and Dedhia H. VSC (Video Spectral Comparator)-6000 HS A Non-Destructive
Technique for Identification of Blood. Austin J Forensic Sci Criminol. 2017; 4(1): 1057. ISSN:2380-0801
4. Application of Video Spectral Comparator for Examination of Printed Material. (2020). Retrieved 20 September
2020, from http://shodhganga.inflibnet.ac.in/bitstream/10603/41233/10/10_chapter%202.pdf
5. Advances in Document Examination: The Video Spectral Comparator 2000 by Mokrzycki (Forensic Science
Communications, October 1999). Retrieved 21 September 2020, from https://archives.fbi.gov/archives/about-
us/lab/forensic-science-communications/fsc/oct1999/mokrzyck.htm
6. Kaur, R., Saini, K., & Sood, N. (2013). Application of Video Spectral Comparator (absorption spectra) for
establishing the chronological order of intersecting printed strokes and writing pen strokes. Science &
Justice, 53(2), 212-219. doi: 10.1016/j.scijus.2012.10.001
7. Webinar on VSC (2020). Retrieved 22 September 2020, from
https://fosterfreeman.clickmeeting.com/599836551/?r=AQtlZmL1ZQu8sRABJH5TIFOnHyIBEKk8L255ozM1r
aW1ozINqUchqaxhpTW6sUjlZwNlAGDjBD____

16. Thank You !