Chemistry Project Report Portion

Michael Valente

Table of contents

1. Introduction
2. History of Photography
3. How does a Camera Work?
4. Steps Involved in Developing Pictures
5. Science Behind Photography
6. The Actual Lab
7. Film Developing Information
8. Photograph Information
9. Conclusion
10. Glossary 
11. References

1.)Introduction

The photography project is a project where we learn the history and science behind photography, as well as the chemistry within the pictures that we take.  Each photo is filled with chemicals and elements and the project shows us the abundance of chemistry that makes our everyday lives possible.  It makes you aware of how much is going on in the world around you, and how important chemistry is to everyday life.  The photography project relates to what we       have learned in class so far this year because it heavily involves chemical formulas and all of the elements that surround us throughout our lives.

Alhazen

Joseph Nicephore Niepce

2.)History of Photography

Photography is, to be simply put, the art or practice of taking and processing photographs.  However, there was once a time when a simple photograph, was anything but simple.  The word photography comes from the Greek words for light(photos) and graphein(to draw).  Oddly enough, the word was first used by the scientist Sir John F.W. Herschel in 1839, after the first photograph was taken.  The first form of a camera came about in 1000 AD.  The revolutionary device was invented by a man named Alhazen, who had great knowledge of optics for the time, and was named the Camera Obscura.  To go back further than that, the Camera Obscura or the "pinhole camera, was made possible around 330 BC, where the great mind of Aristotle questioned how the sun could maintain a circular image when looking through a square hole.  Flash-forward over 2000 years to a summer day in the year of 1827, where a man by the name of Joseph Nicephore Niepce took the first photograph in the history of mankind using Camera Obscura.  To do so, Niepce placed an engraving onto a metal plate coated with bitumen, and then exposed it to light, letting the light draw the picture.  Areas covered with shade remained dark but areas exposed to light underwent a chemical reaction between the light and the chemicals on the plate.  When the metal plate was placed into a solvent, an image would appear.  For the time this was an astronomical advancement in photography despite the fact that the plate needed to be exposed to be late for eight hours and the photo would eventually fade away.  The next greatly influential character in the invention of modern photography would be  Louis Daguerre.  He would form a partnership with Niepce and work to improve his original model.  After ten years of experimenting and the death of his peer, Niepce, Daguerre would develop a newer form of the camera, where the frame only had to be exposed to light for thirty minutes and the picture would not disappear.  Fittingly Daguerre named the camera the daguerreotype, after himself.  The new camera's [plate was "fixed" onto a sheet of silver-plated copper.  The silver was coated in iodine, which was very sensitive to light.  The plate would be soaked in silver chloride, opposed to the old solvent, because it created a lasting image.  Niepce's son, along with Daguerre sold the rights to the daguerreotype to the French government.  The camera would soon become very popular as it served as the world's first camera.  The next great advancement in photography was the invention of tintypes, which were invented by Hamilton Smith in 1856.  A thin sheet of iron was used to provide a base for light sensitive material, yielding a positive image.  This is following the invention of wet plate negatives.  Invented by Frederik Scott Archer in 1851, a piece of glass was coated with light sensitive salts.  The glass created a more detailed picture than the paper.  However, a portable dark room had to be used because the the wet plates had to be developed before the solution dried out.  In 1879 this all changed with the invention of a dry plate.  The plates could be stored and there was no longer a need for dark rooms.  Also, the plate absorbed light so fast it paved the way for the first portable camera.  This was a massive breakthrough in photography as taking a photo was no longer such huge production, and it could be done by more people.  The next advancement in photography came in 1889 when George Eastman created a film role that was flexible and could be rolled.  This discovery was important as it made the mass produced box camera possible.  Finally, the most modern of advancements was that of the colored image, which came about in the 1940s.     

Eastman's First Camera

George Eastman

Louis Daguerre

3.)How does a Camera Work?

Cameras start with a plastic or metal light-tight case that protects the highly light-sensitive film.  The camera has an aperture, or diaphragm, which lets light in whenever you choose to take the picture.  The shutter mechanism on the camera opens and closes to expose the film to light for just the right time.  Then there is the lens of the camera, which serves many jobs at the same time.  First they scale the photo down to a smaller size, so the picture doesn't come out to be life-sized.  The lens also funnels in light so the picture to be taken.  With the lens concentrating the light cameras can take pictures in darker environments and in a shorter amount of time.  Also, the lens projects the light directly onto the film, making the image far clearer than it would be otherwise.  Lastly, it shrinks the space between the aperture itself and the film, making cameras smaller and more portable, opposed to the larger cameras of the past.  Finally, there is the film itself, that with the help of the other components of the camera can for a clear and small image. 

4.)What steps are involved in developing photographs?  

1. The film is placed in a developing agent, which is actually a reducing agent.  The reducing agent will convert all the silver ions into silver metal.  Those grains that have latent-image sites will develop more rapidly.  With the proper temperature control, time and agitation, grain s with latent images will become pure silver.  The unexposed grains will remain as silver-halide crystals.
2. Rinse the film with a stop bath to stop the development process.
3. The unexposed silver-halide crystals are removed in what is called a fixing bath.  The fixer dissolves only silver-halide crystals leaving only the silver metal behind.
4. Finally, the film is washed with water to remove any processing chemicals.  The film is then left to dry and individual exposures are cut into negatives.

Purpose Behind the Following

• development- The development of photos is a process involving many separate chemicals and reactions.

          Exposure- AgBr (UV)-----> (Light) AgBr  (reduction)
          Ag (silver ion) + e (developer) -----> Ag (Silver atom)  (reduction)
          Developer supplies electrons
          Film+ Developer - AgBr----->  Ag + Br2

• stop bath- The purpose of the stop bath is to halt the development of the film, plate, or paper by either washing off the developing chemical or neutralizing it.  
• fixer- The fixer stabilizes the image, removing the unexposed silver halide remaining on the photographic film or photographic paper, leaving behind the reduced metallic silver that forms the image.  Meant to permanemtly attach image to the film.

          Film+ Fixer- AgBr +(NH4)2S2O3-----> NH4Br+ (NH4)5Ag(S2O3)3

• Permawash-Removes excess chemicals.
• Photo Flo- Protects film and makes it flexible
• wash process-  Done to remove any excess chemicals on the film that could hinder with the development. 
• Agitation-  When film gets developed, the developer directly in contact with the film gets exhausted. The agitation brings fresh solution into contact with your film.
•  Temperature-  Have to be at certain temperature for film to develop correctly.

Chemicals in the Following

• Developer- metol, phenidone, dimezone, hydroquinone, sodium carbonate, and sodium sulfite 
• Stop bath(Kodak)- Acetic Acid  (HC2H3O) 
• Fixer(Kodak Professional)- ammonium thiosulfate, sodium sulfite, sodium disulfite, water, sulfuric acid,and aluminum sulfate  
• Perma Wash-  sodium sulfide, ammonium sulfite, and water
• Photo Flo(Kodak)- ethyl alcohol, propylene gyycol, and water 

5.)The Science Behind Photography

There is a great deal of science behind photography, specifically chemistry.  At each new step of developing photos, chemicals are reacting and being introduced,  Silver ions get converted to silver metal in a developing or reducing agent.The silver can turn into silver grain or crystals and into regular pure silver.    Each step needs to be done carefully as slight mistakes or exposure to light at the wrong time can ruin a reaction.  That is how chemicals and science can be used in photography.  

6.)The Actual Lab

Objective-  To gain a better understanding of the chemistry behind photography and the importance of each step and small detail in developing photographs.

Procedure- We first gathered all of our materials.  We then put our film into the canister where it would be mixed with the different fluids that would develop the film.  We would follow each step carefully, and mix for the times that were given to us, to ensure that we did not over, or under develop the film.  After that we the film was ready to be exposed to light and we observed our pictures.

Observations- The film was very sensitive and even the slightest exposure to light at the wrong time would destroy the film.

Conclusion- There is a lot of chemistry involved in photography and it is very important to follow all instructions when developing film.

7.) Film Developing Information

• Water (H2O)
• Metol ((C7H10NO)2SO4)
• Sodium Sulfite (Na2SO3)
• Hydroquinone (C6H6O2)
• Acetic Acid (C2H4O2)
• Sodium Thiosulfate (Na2S2O3)
• Potassium Bromide (KBr)
• Sodium Carbonate (Na2S2O3)
• Sodium Bisulfite (NaHSO3)
• Sodium Acetate (C2H3NaO2)
• Sulfuric Acid (H2SO4)
• Aluminum Sulfate (Al2(SO4)3)
• Ammonium Sulfite ((NH4)2SO3)
• Propylene Glycol (C3H8O2)

8.) Photograph Information

I took photos of my dog, a bookshelf, a bunch of baseballs, a home gym, sugar on a counter, and a water bottle.  I decided that I would take a variety of photos, ranging in their simplicity and detail.  I thought it would be best to have simple pictures, where a chemical list would be simple, as well as very complicated pictures with numerous details and different materials.  (Pictures are not my actual photos, just similiar one.  

Chemical List

Water Bottle on Table

Water Bottle

• Plastic: PET (terphthalic acid + ethylene glycol)
• Water:  H2O

Table

• Wood  cellulose formula is C₆H₁₀O₅
• Laminate
• Adhesive  Polyvinyl acetate.  (C₄H₆O₂)_n.

Wall: Drywall

• Gypsum:  CaSO4

Cotton Sweatshirt

• Cellulose:  91.00%  (CoH)
• Water:  7.85% H2o
• Mineral Salts:  0.20%

Sugar on Granite Counter

• sugar:  C12H22O11
• granite:   SiO2 and Al2O3

My Dog

• muscle:  proteins (actin, myosin) & lipid
• bone:  CA10(PO4)6(OH)2
• fur: keratin water-insoluble proteins (molecular weight range 40-70 K) that form 10-nm tonofilaments in a wide variety of epithelial cells. 

Ceramic Tile

• oxides:  An oxide is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula.  
• kaolin : Al₂O₇Si₂
• feldspar:   Feldspars (KAlSi₃O₈ – NaAlSi₃O₈ – CaAl₂Si₂O₈) 
• quartz:  SiO₂.

Baseballs

Cork

• ash: 25%-45% calcium carbonate, 10 percent is potash, and less than 1 percentphosphate; there are trace elements of iron, manganese, zinc, copper and some heavy metals.^] All of these are, primarily, in the form of oxides.^[5]
• total extractives:  15.3%
• suberin:  38.6% typical suberin, and consists of waxes, fatty acids, ω-hydroxy acids, α,ω-diacids, primary alcohols, and guaiacyl- and syringyl-substituted phenolics. 
• lignin:  21.7%
• polysaccharides:  18.2% (C₆H₁₀O₅)_n

Yarn

• keratin:  water-insoluble proteins (molecular weight range 40-70 K) that form 10-nm tonofilaments in a wide variety of epithelial cells. 

Leather

• animal hide:  keratin

Bookshelf

Paper:

• Cellulose:  (C6H10O5)n
• Hemi-cellulose
• Lignin
• Calcium Carbonate CaCO3.

Weights

• Steel:  84 % iron, 0.7%  carbon, 4 % chromium, 10 % tungsten, and 1% molybdenum.
• Copper Pipe:  Copper  (Cu) 
• Concrete:  a mixture of gravel, sand (SiO2), cement and water (H2O) so does not have a single chemical formula. 

9.) Conclusion

I can conclude that there is a wealth of chemistry involved in developing photos and it is a very delicate process.  Each chemical in the process of developing the film is necessary and it is important to ensure that directions are followed and the film is not exposed to light at a poor time. 

10.)Glossary

Chemistry- the branch of science that deals with the identification of the substances of which matter is composed; the investigation of their properties and the ways in which they interact, combine, and change; and the use of these processes to form new substances.

Photography- the art or practice of taking and processing photographs.

Film- a thin flexible strip of plastic or other material coated with light-sensitive emulsion for exposure in a camera, used to produce photographs or motion pictures.

Develop- to make pictures through exposure to light and chemical reactions.

Atom- the basic unit of a chemical element

Case- External shell of the camera that protects the film from light exposure.

Aperture- a space through which light passes in an optical or photographic instrument, especially the variable opening by which light enters a camera.

Shutter- a device that opens and closes to expose the film in a camera.

Lens- a piece of glass or other transparent substance with curved sides for concentrating or dispersing light rays, used singly (as in a magnifying glass) or with other lenses (as in a telescope).

11.)References

•  http://inventors.about.com/od/pstartinventions/a/stilphotography.htm
• http://www.britannica.com/EBchecked/topic/457919/history-of-photography
• http://photo.net/history/timeline
• Book 1- National Geographic   Science of Everything
• Book 2- Martin W. Sandler   Photography, An Illustrated Story