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The reason why I have taken this theme is that I love to make photographs and I'm very interested in. I never go out, with out a camera or a handy with camera inside. There is always something to take photography of.
Since approximately one year, I feature a digital SLR (Single Lens Reflex) camera and I want to know now more about it, to use her better.
Also I'm interested in old analogue cameras like Polaroid's and Lomo's. Therefore I own a small fisheye Lomo camera that makes pretty nice pictures.
All of those themes I would now integrate in my project and give an overview about them.
I would like to answer some questions in the course of my interdisciplinary project, like:
- Digital Photography - How it works
- Analogue Photography - How it works
- The developing of Photos
- Other Photo techniques (Polaroid, Lomo etc)
I will present you the two main modes from photography. First I show you some details about digital cameras. That means how the resolution of pictures works, something about saving pictures, the exposure and at least the with balance.
After that I switch to the opposite side, the analogue camera. There I'll tell you something about the photographic film, film speed and at least the way of light.
In addition, I want to take focus on the film developing. I'm very interested in that. I want to show you which materials are needed for a photo labor and how it is composed. Later I give a focus on the process of film developing. Which methods are needed for colored images and which for black & white images.
As I said in the upper part, I go a little inside into other photo techniques. (Lomo and Polaroid)
How A Digital Camera Works
Resolution of a picture
The resolution is a Mass for the vertical and horizontal density from a digital Image. Every digital Image is like a mosaic. Every Image is made with millions of ultra small rectangles - called pixels. When we zoom in a picture, we can see them. Every pixel has it own color and brightness that give composed to each other, the whole picture in the end.
One megapixel (MP) is equal to one million pixels. It's needed for the resolution of the photos. The more megapixels the camera has, the higher is the resolution of the photo.
Sometimes we want to make a poster or just print out our images. For posters we need a higher resolution (and more megapixels) than for normal small print outs.
In the table on the bottom, we can see, for which size, how many megapixels would be needed.
For each picture we would take, millions of calculations are needed. They have to be made in a few seconds. The camera needs them, to display, preview, filter, transfer, compress, store and interpolate the image.
It's similar to a desktop computer, because all of these calculations are performed in the camera by an image processor, but adapted to single tasks.
It's critical to the quality of the pictures, how well the processor performs its function. But it's hard to appreciate if that is true or not, because for the most of us, those blackchips are a bit mysterious and we don't know if the advertisers say the whole truth about them.
At the moment, the newest programmable digital media processors can do a lot of things like:
Redeye removal, image enhancement, picture borders, panorama pictures, removing blur and much more.
Digital cameras use a solid state device (image sensor) to capture the image. Some cameras have a chargecoupled device (CCD) or a CMOS sensor. Both deliver good results. On this very small silicon chips are millions of photosensitive diodes, each of these are a single pixel in the photograph.
If we take now a picture, the shutter opens quick and let some light inside. The pixels on the image sensor record now the brightness of the light. All this happens by an electrical charge.
The values from each pixel would measure, after the shutter has closed. Then those values would be converted into a digital number.
The camera needs those digital numbers now, to reconstruct the image by setting the color and brightness.
The camera will collect the amount of light during a single picture. This action is called exposure.
If the exposure is adjusted too short, the photo will be too dark. (The same if the exposure is too long - too bright picture). All of the digital Cameras in this century have an automatically exposure which measure the light in the given shot. Most of the people use this feature but if you want to make special, more interesting and better pictures, you shouldn't use it and shift it by yourself.
The two main controls for the camera uses for exposure are shutter speed and aperture. The Shutter speed is the amount of time the sensor is exposed to the light. The aperture is the size of lens opening that lens light into the camera.
Shutter speed is measured in seconds, aperture in f/stops.
In the following table you can see some facts about the shutter and the aperture:
Both of those two controllers can also be used for other aspects of the picture.
For example, shutter speed can be used to freeze fast things, like a driving car or a running man. Also it can blur water with a slow speed.
Aperture controls the focus and can be used to draw attention to one object. Aperture can blur the background and focusing the preferred object.
(bilder mit fokus von einem objekt und bilder mit schnelligkeit).
To change the sensitivity of the sensor when collecting light, we can use the ISO speed. That's a common currency for that. 100 to 800 is the normal span of ISO speed.
It adds more noise in to the photo, if the ISO speed is very high and the camera would be faster at collecting light.
(bild mit hohem iso und bild tiefem iso)
White balance (WB) is to set the colors of the pictures as accurate as possible. When we make a photograph of an object under the bright sun, the image would shine in ‘warm' colors like red or orange. If we put the same object under a lamp, the image have a blue and ‘cold' touch. Sometimes an image wouldn't be nice with such color bugs. In case of this, most of the newer cameras have an auto WB to set the optimal light in the photo that it looks ‘realer'.
For this, the auto WB catches the light from a white/light grey point in the focused picture and safe this value as the color ‘white'. If we take then a picture, de camera will convert all colors with this ‘white value' from before and create a photo from that. Sometimes the focused white point isn't ‘real' white or light grey because of the light ratio (bright sun, lamp, cloudy etc.).
For that we can handle the WB manually (by focusing a white point by our own) or go into the settings of the camera and choose one of the preinstalled settings.
In the table on the bottom we can see some preinstalled settings like they are in cameras.
How an analogue camera works
In today's age, it's almost extinct. Most of the people use now digital cameras. However, it's still exist the analog camera.
For each picture we would take with an analogue camera, we have to put in a photographic film.
He's made of plastic and used to record pictures. This plastic is covered with chemicals that react when light shines on. When we later develop the picture, it's possible to record an invisible picture with this film, when it is exposed to light.
It will do this whit a collection of tiny, lightsensitive grains, which spreads out in a chemical suspension on the plastic film stripe. When light touches those grains it will give a chemical reaction.
This film has different layers who are only a few thousands of an mm thick. A special gelatin glues those layers together. Those layers are used to form images but some layers aren't used for this. They exist to filter light or to control the chemical reactions in the processing steps later.
There are different types of photographic film. Some films are for black and white images and some for colored ones. They can be bought in different sizes. The most common one is 35mm. This number means the width of the film.
Photographic film is very sensitive to light and he has limited exposure latitude. If the film is underexposed, it will not show all the reflected light from a scene. The resulting print is muddy black or gray and hasn't got many details. The reverse happens, when the film gets overexposed. Then all of the silverhalidegrains on the film are exposed and we can't see any discrimination between lighter and darker parts of the scene.
For each film we buy, we have to choose a film speed. Film speed is declared in the ISO (International Standards Organization) rating.
The ISO speed is to make the film faster or slower. Faster means increased light sensitivity.
The faster the film, the higher the ISO rating.
The way of light If we push the button to make a picture, the shutter will open and let some light inside. The photographic film who is placed inside the camera box, will record this light. To let light shining on the film is called “exposing”.
Before the light will touch the photographic film it goes trough the lens. When it starts to pass the lens the light bends. It also bends when the light exits the lens because parts of the light waves enter the air and speed up before other parts of the light. This will make, that the path of light from an object will reverse. So that in the end, the pictures is reversed.
Black And White Film
It's easier to develop a black and white film than a colored film. On a black and white the silverhalid grains are coated in just one or two layers. On the colored film are more, because they have to be light sensitive to red, green and blue wavelength.
For the development I took a part from the HowStuffWorks webpage: 19982010, because it describes the development of black and white film good and in short sentence.
1. In the first step of processing, the film is placed in developing agent that is actually a reducing agent. Given the chance, the reducing agent will convert all the silver ions into silver metal. Those grains that have latentimage sites will develop more rapidly. With the proper control of temperature, time and agitation, grains with latent images will become pure silver. The unexposed grains will remain as silverhalide crystals.
2. The next step is to complete the developing process by rinsing the film with water, or by using a "stop" bath that arrests the development process.
3. The unexposed silverhalide crystals are removed in what is called the fixing bath. The fixer dissolves only silverhalide crystals, leaving the silver metal behind.
4. In the final step, the film is washed with water to remove all the processing chemicals. The film strip is dried, and the individual exposures are cut into negatives.
After this process we only have the negative of the film. Now we have to print this negative on an other light sensitive material (Normally photographic paper).
Print the black and white film
Now we have the choice of an enlargement or a direct contact print, to print the negative on a photographic paper.
If we want a larger size, we have to have an enlarger (a projector with a lens for focusing the image and a controlled light source).
Now we place the negative in the enlarger and project it onto a flat surface. Now we can focusing the picture and set the size. If the size is correct, all the light have to be shut off. The photographic paper has to be placed now on the flat surface and for a short time, exposed with the light source from the enlarger. Now the silver grains are exposed and it happen the same as before, for the negative film. The film will be formed, while the grains are exposing by light.
At the end the paper has to be washed with water, to execute rests of the chemicals.
Colored film is a bit more difficult as black and white. We have to use more chemicals and the developing times changes.
On the same webpage as before for the black and white film, HowStuffWorks: 19982010, I found a good explanation for colored film developing.
1. The development step uses reducing chemicals, and the exposed silverhalide grains develop to pure silver. Oxidized developer is produced in this reaction, and the oxidized developer reacts with chemicals called couplers in each of the imageforming layers. This reaction causes the couplers to form a color, and this color varies depending on how the silverhalide grains were spectrally sensitized. A different colorforming coupler is used in the red, green and bluesensitive layers. The latent image in the different layers forms a different colored dye when the film is developed.
- Redsensitive layers form a cyancolored dye.
- Greensensitive layers form a magentacolored dye.
- Bluesensitive layers form a yellowcolored dye.
2. Now we have to put the negatives in a stop bath or wather bath, to stop the developer process.
3. The unexposed silverhalide grains are removed using a fixing solution.
4. By add bleaching chemicals, the silver (that was developed in the first step), would be removed.
5. The last step is, to wash the negative image to remove the rest of the chemicals and reaction products. Then the film stripes are dried.
The developed film negative looks different than the black and white one. The colored film contains no silver and that's the reason why the film looks more red/orange.
As same as the black and white film we have to print the negative now to a photographic paper, that our eye can see it “normally”.
Print The Colored Film
The colored film has to be print as same as the black and white one.
“The major difference comes in the printing process, where long rolls of color paper are preloaded into paper. The roll of negatives is loaded, and the printer operator works in normal lights to preview each negative and make adjustments to the color balance (©19982010HowStuffWorks, Inc.)”.
The color balance is adjusted by adding subtractive color filters to make the print more pleasing, particularly when it has been exposed incorrectly. There is only so much correction that can be done, so don't expect miracles. Once a full roll of paper is exposed, or a single roll of film has been printed (in the case of a minilab), the paper is processed.
The latentimage sites are developed, and oxidized developer molecules combine with the colorforming couplers to create a silver image and a dye image. The reaction is stopped by a washing step.
2. The silver image and any remaining unexposed silver halide is removed in a combined bleachplusfix solution (called the BLIX).
3. The print is then carefully washed to remove any residual chemicals.
- The print is dried.
Lomography was detected in 1990 in Vienna, Austria. Two students discovered a small Russian camera and they made lots of funny pictures. They thought that it's a good idea to travel and make pictures all over the world.
Lomography became a international sociocultural movement and is till now used to absorb and capturing the world and communicating in a creative way.
Normally all Lomo cameras are analogue ones. With special filters or lenses, we can change the effects of the pictures.
It gives a lot of different Lomo cameras to buy, like: Fisheye, Multilense, Pinhole, Russian, Panoramic or much more.
There are 10 golden rules for Lomography and its philosophy:
1. Take your camera everywhere you go
2. Use it any time - day and night
3. Lomography is not an interference in your life, but part of it
4. Try the shot from the hip
5. Approach the objects of your lomographic desire as close as possible
6. Don't think (William Firebrace)
7. Be fast
8. You don't have to know beforehand what you captured on film
9. Afterwards either
10. Don't worry about any rules
I have a Lomo Camera at home who makes fisheye pictures. I really love to photograph with this, because it's funny and you never now in the beginning, how the picture will look like. It makes it exciting. When I make pictures with my digital SRL camera, the images will be placed in a folder on the computer and I will never touch them again. With Lomo pictures it's something else, because I can hold those images in the hands, hang them on my wall or something else. It makes me happy and I always get nervous when the postman brings my new developed pictures.
Edwin Land introduced in 1947 a new camera. This camera could develop a film by itself in few minutes.
How Polaroid works:
The instant film has three layers who are sensitive to different colors of light. All of the different colored layers have underneath a developer layer who is containing dye couplers.
They are all arranged on the top of the black base layer. Over those colored layers is the image layer, the acid layer and the timing layer. In this arrangement, they are waiting to be set in motion with a chemical chain reaction.
Now we have the film, but how does it now work, that the picture gets developed after the print out?
All of the regent materials are collected in a blob at the border of the plastic sheet. They are away from the lightsensitive materials because otherwise they would develop the film before he is ready. The film sheet passes out of the camera, after snap the picture, trough a pair of rollers.
These rollers give a little pressure on the film, so that the regent material spread out into the middle of the film sheet. The lightsensitive chemical layers react now and changing the exposed particles into metallic silver.
The developer dye begins to diffuse up the image layer, after the chemicals are dissolved. Then all metallic silver areas at each layer grab the so they stop moving up.
I think it was a good idea from Edwin Land to introduce this new camera. It's something special to hold an image in the hands, after a few minutes you shoot it. I wish I had such a Polaroid camera. It's a big wish of mine to have her. Sadly the camera is taken out of the assortment. We can find some of these cameras in Ebay or Riccardo.ch and they aren't expensive but the Film for those cameras is really rarely and very expensive.
Trough this project I became a better view about the photography. I learned much about the analogue photography and also about the digital one.
I was very motivated and interested through my work, because the photography is something I love since I get my first camera with 11 years.
I'm also interested in imperfect pictures. That means pictures that look different than all those perfect and sharp pictures from the media. Those pictures I make with my Lomo camera or with some apps on my Iphone.
That's the reason why I also integrate some sites in my project with “other photo techniques”.
I'm astonished that the film developing takes so long with such different kinds of materials, exposure times etc. I tough that film developing is easy but it isn't.
Once in my photographic carrier I would develop my own pictures in my own lab or in an rentable one.
I have progressed pretty well with my interdisciplinary project. The organization of the time, succeed well.
All in all I am satisfied with my work and I hope that I could give you an overview about photography and its topics.
How a digital camera work
Resolution of a picture
Table copied from:
Table copied from:
How an analogue camera works
Black and white film
Lomo: Taken by myself
Negative color film: http://www.joereifer.com/words/images/2008/santafesprockets.jpg
Black and white film: http://blogs.reuters.com/photo/files/2009/01/crawford1.jpg
Film roll color: http://allieddigitalphoto.com/images/filmroll_high.jpg