A latent image is an invisible image produced by the exposure to light of a photosensitive material such as photographic film. When photographic film is developed, the area that was exposed darkens and forms a visible image. In the early days of photography, the nature of the invisible change in the silver halide crystals of the film's emulsion coating was unknown, so the image was said to be "latent" until the film was treated with photographic developer.
In more physical terms, a latent image is a small cluster of metallic silveratoms formed in or on a silver halide crystal due to reduction of interstitial silver ions by photoelectrons (a photolytic silver cluster). If intense exposure continues, such photolytic silver clusters grow to visible sizes. This is called printing out the image. On the other hand, the formation of a visible image by the action of photographic developer is called developing out the image.
The size of a silver cluster in the latent image can be as small as a few silver atoms. However, in order to act as an effective latent image center, at least four silver atoms are necessary. On the other hand, a developed silver grain can have billions of silver atoms. Therefore, photographic developer acting on the latent image is a chemical amplifier with a gain factor up to several billion. The development system was the most important technology that increased the photographic sensitivity in the history of photography.
Security printing is the field of the printing industry that deals with the printing of items such as banknotes, cheques, passports, tamper-evidentlabels, product authentication, stock certificates, postage stamps and identity cards. The main goal of security printing is to prevent forgery, tampering, or counterfeiting. More recently many of the techniques used to protect these high-value documents have become more available to commercial printers whether they are using the more traditional offset and flexographic presses or the newer digital platforms. Businesses are protecting their lesser-value documents such as transcripts, coupons and prescription pads by incorporating some of the features listed below to ensure that they cannot be forged or that alteration of the data cannot occur undetected.
A number of technical methods are used in the security printing industry.
Special paper
Most banknotes are made of heavy paper, almost always from cotton fibres for strength and durability, in some cases linen or speciality coloured or forensic fibres are added to give the paper added individuality and protect against counterfeiting. Some countries, including Nigeria, Romania, Mexico, New Zealand, Israel, Singapore, Malaysia and Australia, produce polymer (plastic) banknotes, to improve longevity and allow the inclusion of a small transparent window (a few millimeters in size) as a security feature that is difficult to reproduce using common counterfeiting techniques. In November 2011 Canada joined the list of countries using polymer currency as it began the introduction of a new banknote series.
LATENT IMAGE FORMATION || INVISIBLE IMAGE || PROCESSING OF FILM || ORAL RADIOLOGY || made easy
Hello everyone. Topic for today Is latent Image formation from processing of Xray film.
Links for contacting me for the books- DM 📩
Instagram- http://www.instagram.com/dentistrymadeeasy_
Email id- [email protected]
Telegram link- https://t.me/dentistrymadeeasy
*None other than above mentioned links, pages or person have the rights to sell the books so don’t engage in buying them as they can land into legal problems.
#Dentistrymadeeasy
published: 19 Oct 2021
6. Latent Image Formation in Film-Screen Radiography RADIOGRAPHIC IMAGING
We look at The Gurney-Mott Theory of Latent Image Formation in Film-Screen Radiography. We highlight the contents of a film emulsion layer
We want to hear from you. Let us know in the comment section or via email ([email protected]) what new topics you want covered and how we can serve you better.
Please SUBSCRIBE and SHARE with your colleagues as this would go a long way in helping us reach more people.
Music Credit: https://www.bensound.com
published: 15 Aug 2020
Latent Image Presentation
In this presentation, I provide some context for the Star Trek Voyager episode "Latent Image" and its representation of PTSD.
published: 16 Oct 2020
Latent image formation l defects in crystal l Radiographic film part-2 lRadiography Simplified l
Hi friends 👋
Welcome to my channel.
Radiographic film part - 1
https://youtu.be/mIs6ERi4ZTs
I am posting a video on latent images formation and crystal defects.
emulsion is a homogenous mixture of gelatin and silver halide crystal.
It is light sensitive material.
Silver halide crystal contain 90 -99% silver bromide and 1- 10% silver iodide.
it is formed from the ions silver, ion of bromine & ions of iodine arrange in cubic lattice
crystal defects-: variation in regular arrangement of atom and molecules of a crystal.
1) point defects-: if a silver ion move out of its normal position in the crystal lattice it create point defect these interstitial silver ions may move in the crystal.
2) linear defects -: it cause when crystal contain misaligned planes of atoms they are re...
published: 28 Jan 2021
Latent Image Formation
This video presentation is about how latent image is formed in an x-ray film, as the first step in the photochemical process of radiographic image formation.
Hello everyone. Topic for today Is latent Image formation from processing of Xray film.
Links for contacting me for the books- DM 📩
Instagram- http://www.insta...
Hello everyone. Topic for today Is latent Image formation from processing of Xray film.
Links for contacting me for the books- DM 📩
Instagram- http://www.instagram.com/dentistrymadeeasy_
Email id- [email protected]
Telegram link- https://t.me/dentistrymadeeasy
*None other than above mentioned links, pages or person have the rights to sell the books so don’t engage in buying them as they can land into legal problems.
#Dentistrymadeeasy
Hello everyone. Topic for today Is latent Image formation from processing of Xray film.
Links for contacting me for the books- DM 📩
Instagram- http://www.instagram.com/dentistrymadeeasy_
Email id- [email protected]
Telegram link- https://t.me/dentistrymadeeasy
*None other than above mentioned links, pages or person have the rights to sell the books so don’t engage in buying them as they can land into legal problems.
#Dentistrymadeeasy
We look at The Gurney-Mott Theory of Latent Image Formation in Film-Screen Radiography. We highlight the contents of a film emulsion layer
We want to hear from...
We look at The Gurney-Mott Theory of Latent Image Formation in Film-Screen Radiography. We highlight the contents of a film emulsion layer
We want to hear from you. Let us know in the comment section or via email ([email protected]) what new topics you want covered and how we can serve you better.
Please SUBSCRIBE and SHARE with your colleagues as this would go a long way in helping us reach more people.
Music Credit: https://www.bensound.com
We look at The Gurney-Mott Theory of Latent Image Formation in Film-Screen Radiography. We highlight the contents of a film emulsion layer
We want to hear from you. Let us know in the comment section or via email ([email protected]) what new topics you want covered and how we can serve you better.
Please SUBSCRIBE and SHARE with your colleagues as this would go a long way in helping us reach more people.
Music Credit: https://www.bensound.com
Hi friends 👋
Welcome to my channel.
Radiographic film part - 1
https://youtu.be/mIs6ERi4ZTs
I am posting a video on latent images formation and crystal de...
Hi friends 👋
Welcome to my channel.
Radiographic film part - 1
https://youtu.be/mIs6ERi4ZTs
I am posting a video on latent images formation and crystal defects.
emulsion is a homogenous mixture of gelatin and silver halide crystal.
It is light sensitive material.
Silver halide crystal contain 90 -99% silver bromide and 1- 10% silver iodide.
it is formed from the ions silver, ion of bromine & ions of iodine arrange in cubic lattice
crystal defects-: variation in regular arrangement of atom and molecules of a crystal.
1) point defects-: if a silver ion move out of its normal position in the crystal lattice it create point defect these interstitial silver ions may move in the crystal.
2) linear defects -: it cause when crystal contain misaligned planes of atoms they are referred as dislocation . since atom are dislocated from their normal position in the lattice .
Dislocation is line imperfection in the crystal.
iodine ions strain the crystal in this way.
3) chemical sensitization-: allylthiourea is a sulphur containing compound when mixed with emulsion it produces chemical sensitization.
Which react with silver halide to form silver sulphide.
silver sulphide is usually located on the surface of crystal and is called sensitivity centre.
this sensitivity centre trap the electron and begin the formation of latent image.
Latent image :- when x-ray film is exposed from the light Photon from intensifying screen it creates and invisible image on the radiographic film called latent image.
In this process the light from the intensifying screen strike the crystal and bromine iron absorb the photon and release electron and converted into bromine atom and moves to gelatin/ emulsion.these liberated electron trapped at the the sensitivity centre and sensitivity centre acquired negative charge the negative charge.
sensitivity centre start attracting free silver iron and convert them into neutral metallic silver atom and this process is repeated many time and more and more silver ion is converted into metallic silver atom.
Accumulation of these metallic silver atom result in the formation of invisible image called latent image.
Please like share and subscribe my channel.
Don't forget to press the bell icon so that you can get updates of my new videos
Thanks for watching,🙏
Bye
Take care.🙏
Hi friends 👋
Welcome to my channel.
Radiographic film part - 1
https://youtu.be/mIs6ERi4ZTs
I am posting a video on latent images formation and crystal defects.
emulsion is a homogenous mixture of gelatin and silver halide crystal.
It is light sensitive material.
Silver halide crystal contain 90 -99% silver bromide and 1- 10% silver iodide.
it is formed from the ions silver, ion of bromine & ions of iodine arrange in cubic lattice
crystal defects-: variation in regular arrangement of atom and molecules of a crystal.
1) point defects-: if a silver ion move out of its normal position in the crystal lattice it create point defect these interstitial silver ions may move in the crystal.
2) linear defects -: it cause when crystal contain misaligned planes of atoms they are referred as dislocation . since atom are dislocated from their normal position in the lattice .
Dislocation is line imperfection in the crystal.
iodine ions strain the crystal in this way.
3) chemical sensitization-: allylthiourea is a sulphur containing compound when mixed with emulsion it produces chemical sensitization.
Which react with silver halide to form silver sulphide.
silver sulphide is usually located on the surface of crystal and is called sensitivity centre.
this sensitivity centre trap the electron and begin the formation of latent image.
Latent image :- when x-ray film is exposed from the light Photon from intensifying screen it creates and invisible image on the radiographic film called latent image.
In this process the light from the intensifying screen strike the crystal and bromine iron absorb the photon and release electron and converted into bromine atom and moves to gelatin/ emulsion.these liberated electron trapped at the the sensitivity centre and sensitivity centre acquired negative charge the negative charge.
sensitivity centre start attracting free silver iron and convert them into neutral metallic silver atom and this process is repeated many time and more and more silver ion is converted into metallic silver atom.
Accumulation of these metallic silver atom result in the formation of invisible image called latent image.
Please like share and subscribe my channel.
Don't forget to press the bell icon so that you can get updates of my new videos
Thanks for watching,🙏
Bye
Take care.🙏
This video presentation is about how latent image is formed in an x-ray film, as the first step in the photochemical process of radiographic image formation.
This video presentation is about how latent image is formed in an x-ray film, as the first step in the photochemical process of radiographic image formation.
This video presentation is about how latent image is formed in an x-ray film, as the first step in the photochemical process of radiographic image formation.
Hello everyone. Topic for today Is latent Image formation from processing of Xray film.
Links for contacting me for the books- DM 📩
Instagram- http://www.instagram.com/dentistrymadeeasy_
Email id- [email protected]
Telegram link- https://t.me/dentistrymadeeasy
*None other than above mentioned links, pages or person have the rights to sell the books so don’t engage in buying them as they can land into legal problems.
#Dentistrymadeeasy
We look at The Gurney-Mott Theory of Latent Image Formation in Film-Screen Radiography. We highlight the contents of a film emulsion layer
We want to hear from you. Let us know in the comment section or via email ([email protected]) what new topics you want covered and how we can serve you better.
Please SUBSCRIBE and SHARE with your colleagues as this would go a long way in helping us reach more people.
Music Credit: https://www.bensound.com
Hi friends 👋
Welcome to my channel.
Radiographic film part - 1
https://youtu.be/mIs6ERi4ZTs
I am posting a video on latent images formation and crystal defects.
emulsion is a homogenous mixture of gelatin and silver halide crystal.
It is light sensitive material.
Silver halide crystal contain 90 -99% silver bromide and 1- 10% silver iodide.
it is formed from the ions silver, ion of bromine & ions of iodine arrange in cubic lattice
crystal defects-: variation in regular arrangement of atom and molecules of a crystal.
1) point defects-: if a silver ion move out of its normal position in the crystal lattice it create point defect these interstitial silver ions may move in the crystal.
2) linear defects -: it cause when crystal contain misaligned planes of atoms they are referred as dislocation . since atom are dislocated from their normal position in the lattice .
Dislocation is line imperfection in the crystal.
iodine ions strain the crystal in this way.
3) chemical sensitization-: allylthiourea is a sulphur containing compound when mixed with emulsion it produces chemical sensitization.
Which react with silver halide to form silver sulphide.
silver sulphide is usually located on the surface of crystal and is called sensitivity centre.
this sensitivity centre trap the electron and begin the formation of latent image.
Latent image :- when x-ray film is exposed from the light Photon from intensifying screen it creates and invisible image on the radiographic film called latent image.
In this process the light from the intensifying screen strike the crystal and bromine iron absorb the photon and release electron and converted into bromine atom and moves to gelatin/ emulsion.these liberated electron trapped at the the sensitivity centre and sensitivity centre acquired negative charge the negative charge.
sensitivity centre start attracting free silver iron and convert them into neutral metallic silver atom and this process is repeated many time and more and more silver ion is converted into metallic silver atom.
Accumulation of these metallic silver atom result in the formation of invisible image called latent image.
Please like share and subscribe my channel.
Don't forget to press the bell icon so that you can get updates of my new videos
Thanks for watching,🙏
Bye
Take care.🙏
This video presentation is about how latent image is formed in an x-ray film, as the first step in the photochemical process of radiographic image formation.
A latent image is an invisible image produced by the exposure to light of a photosensitive material such as photographic film. When photographic film is developed, the area that was exposed darkens and forms a visible image. In the early days of photography, the nature of the invisible change in the silver halide crystals of the film's emulsion coating was unknown, so the image was said to be "latent" until the film was treated with photographic developer.
In more physical terms, a latent image is a small cluster of metallic silveratoms formed in or on a silver halide crystal due to reduction of interstitial silver ions by photoelectrons (a photolytic silver cluster). If intense exposure continues, such photolytic silver clusters grow to visible sizes. This is called printing out the image. On the other hand, the formation of a visible image by the action of photographic developer is called developing out the image.
The size of a silver cluster in the latent image can be as small as a few silver atoms. However, in order to act as an effective latent image center, at least four silver atoms are necessary. On the other hand, a developed silver grain can have billions of silver atoms. Therefore, photographic developer acting on the latent image is a chemical amplifier with a gain factor up to several billion. The development system was the most important technology that increased the photographic sensitivity in the history of photography.