Even Though a photograph doesn't have the impact of a good painting it is still far easier to create, with technological advances and has far greater accuracy since the camera takes a still of what the observer is seeing, "the camera never lies". This is not always technically true, since cameras cannot always pick up the colour diversity and three dimensional effect of what the observer sees.
The invention of the camera cannot be accredited to one man. It was a process that took a long time. Some say it began in 1727 with Johann Heinrich Schulze who discovered that silver nitrate darkened on exposure to light. Then in 1814, nearly ninety years later, Joseph Nicephore achieved the first photographic image with "camera obscura", however, the image took eight hours of light exposure to form and later faded. In the years that followed, the process was refined and perfected, and in 1837 a man called Da guerre took a photograph that was fixed, did not fade and only took half an hour of light exposure. In 1841, William Henry Talbot produced the first negative-positive process making the first multiple copies possible. By 1851 images needed only 2-3 seconds to form.
Early last century, the camera was very expensive basically due to the expense of the materials and the painstaking process of making a lense and other components. Therefore, only the very rich would own one. In addition, with the unportable nature of the camera it wasn't of much use to the average person. Real camera moments are, in my opinion, spontaneous and so it is not as if you could be walking along the beach one hundred years ago, see a sunset, decide you want to take a picture of it and then pull your TV size, 20kg camera out of your shirt pocket. It would always be left at home unless you were attending a wedding or some other event of some importance.
It was not until the camera was seriously reduced in size (made portable) and dropped in price that it really caught on and became a household item. In the USA today 98% of all households have a camera and the number of households with digital cameras is rapidly increasing.
A good camera from the high street can be as cheap as £50 so basically everyone, realistically, can afford one. There are also cameras designed for the expert photographer. These cameras can cost upwards of £2000 and are extremely complicated with every kind of button to tweak and manipulate every aspect of the photograph.
On a very basic level, the camera works by allowing light to hit a light sensitive medium (i.e. the film) which becomes a lighter shade when light pressure is incident on it. The camera can have changing periods of exposure to light which causes images to appear brighter but can cause blurriness if it is exposed for too long. Light from the image is passed through the hole, called an aperture, at the front of the camera and is then focused by the lens onto the film which forms the picture. Obviously brighter objects will produce more light that hits the film and therefore produces a brighter image.
The digital camera, I assume, works by the same method except that instead of focusing the light onto a film, the lens focuses the light onto a CCD (charged couple device) which stores photoelectrons in millions of tiny "wells" in the pixels which are about 9micrometers square. Differing electron levels indicate differing brightnesses of light coming from the object. This arrangement is highly digital and can be stored on a chip and accessed at will and therefore transferable to computers etc.
It was really the newspaper industry that the camera was crucial to and during the war years that the newspaper industry became extremely important. Now, newspapers could have photographically backed up news of incidents occurring in Britain and overseas to do with the war.
During the inter-war years the modern flashlight was invented by General Electric which enabled photographs to be taken in darkness.
Again during the Second World War the newspaper industry was massive because the most important thing on everyone's mind was how the war was progressing, which could not have been reported without photographic evidence.
Possibly even more important than the reporting of events is the benefits the photograph has had on historical records. Very shortly, everyone who was alive during World War One will be deceased, therefore, there will be no first hand accounts of what occurred during the wars. However, with photographs taken during the wars and indeed during any part of the last two hundred years, we have first hand evidence of what actually went on.
Not only was reporting during the war a great use for the camera but also it was used for mission briefings and to give troops images of targets and landmarks etc.
Forty years ago, the US navy acquired depth underwater cameras. This is not only essential for the navy but also for marine scientists who would like more visual information on life deep underwater.
Recently, the hubble space telescope has been taking many photographs of galaxies and stars many thousands of light years away. Obviously, since the earth is so far away from these galaxies, the light reaching the lense is very sparse and so not much of an image is formed. However, on the assumption that objects this far away would have to be traveling extremely fast tangentially to make any change in position with respect to the telescope relevant, it is possible just to leave the camera exposed for a long time of possibly days to get a good photograph with no blurring. This has been essential to gathering information for cosmologists and astronomers on how the universe has formed and what distant celestial objects physically look like.
Cameras, up until quite recently, were very cumbersome devices. In old shows of pictures being taken at weddings there was always a photographer under a black sheet looking through an eyepiece of a large wooden and brass camera the size of a television held up on a tripod pulling a string down and once this had been done there was an almighty flash.
I suppose the black sheet was to avoid sunlight spoiling the film, a bit like a portable dark room. The camera was huge because it needed to fit the film which was huge because the individual frames were a lot larger than the present day and the tripod would have made sure the camera didn't move with respect to the "photographees" as to avoid blurring because the exposure was longer to let in as much light as possible to expose the not so sensitive film.
Nowadays, the camera is a small device the size of a novel made with plastics and lighter alloys. Plastics are far easier to manufacture and mould into the correct shapes than wood or brass. The wood used in the cameras would have been carefully crafted and treated to last longer and varnished, this all adds to the cost.
There is no need for the black sheet because the film is a lot smaller, due to the fact the frames are smaller because of new techniques and materials and fits inside the camera in a spool that prevents light from entering. The tripod is not required because the exposure is shorter because the film is more sensitive and hence blurring can only occur when objects are moving very fast.
Obviously there is a limit as to how small a camera can become given that it has to be big enough to not drop out of your hand. However, with the continual improvement of camera attributes, there appears to be a balance between cameras getting bigger to support greater capacity of taken pictures and resolution along with other bells and whistles mentioned below and the ability to make the same technology but smaller and lighter.
When light is passed through a lens there is a spreading out of the light from red to blue because red and blue have different wavelengths. This effect is called dispersion and in cameras is called "Chromatic Aberration". This effect was eliminated by using the combination of the crystallization of CaF2 (Calcium Fluoride) to make Fluorite which is used for most lenses because it has a very low optical dispersion index and the use of an achromatic doublet.
Any spherically curved lens cannot converge parallel light rays at a single focal point completely. So a lens was invented called the aspherical len,s which is not curved at the same rate over the whole lens, which brings rays hitting the surface at different places into focus at the same point.
LCD Screens
LCD Screens allow you to see the picture before and just after you take it.
So you can also decide which pictures to print before putting them onto paper.
Therefore, the developing cost is less because you obviously only print the
photos worth having and not the ones of people sleeping with their party-hat
on at Christmas.
No film
Digital cameras can store 100s of pictures, or the equivalent of 60+ rolls
of film and not only this but you don't have to replace the chip every time,
so once you have a memory card it lasts until you buy a new camera. You can
simply delete the old photos off of it to free space. Alternatively using
a USB (For non-technical people - a port that enables you to transfer data
very quickly from one medium onto your computer) you can save images in high
resolution on your computer.
Small size
Digital cameras, like mobile phones, are getting smaller all the time. Cameras
are now available that you can easily slip inside a pocket.
Image editing
Your pictures are now no longer finished after you have taken them. You can
change them using a variety of software packages. Alter colours, resize or
cut and paste sections of your photos, and you can even use your pictures
to make cards, art or jigsaw puzzles.
Rotating Lenses and Self Timers
A novel feature is the rotating lens. This allows you to take pictures at angles
and can come in handy if you wish to take a self portrait. Be aware some cameras
that offer a rotating lens only cover 90 or 180 degrees.
I was lucky enough to get a digital camera for my Christmas. It is fantastic and takes pictures with 2400x1600 resolution and has very straightforward controls. However, with that resolution the camera can only store 7 pictures on the 8mb card that came with it. Fortunately, I have also bought a 128mb card which can store lots more pictures. Another draw back of this camera is that it needs 4 AA batteries to power it and batteries are expensive, but to solve this problem I have bought rechargeable batteries. Therefore, the amount I have spent on this camera will be all the money I ever spend on it (apart from printing the pictures) whereas with a film camera I would still be buying spools and developing all the rubbish pictures which I am so fond of taking.
Below are a couple of the better pictures I have taken;
Above is a picture of the Westburn Park. My friends and I used to race sticks down the burn. For non Aberdonians, from the direction of the picture if you followed the trajectory through the pub at the far right for about 150m you would roughly be standing in the childrens ward of Aberdeen Royal Infirmary.
Here is the other end of Westburn park. If you kept walking for another 250 metres, and climbed every gate and wall, you would be standing on my street which is about 150 metres from sainsbury's in that direction. Please check back regularly for some great photos.
Here is a 1/30 s exposure of a fire I built, whilst camping up at Templars Park. All these photos are one third the quality that I actually take just so they fit on the website and that it loads in under a year.
Wierd wobbly building due to refractive index of water being different to air
This is a really cool picture of a hotel in Glasgow taken through a rained on window. I assure you that the hotel is perfectly straight.
Below are just some links to download more photos I have taken on my holidays.Please note though, unfortunately I have not uploaded the photo I took whilst walking to Banchory of a Pig farm.
For second year physics we have been required to write a few reports and essays so below are three which I would be glad for people to read, enjoy and possibly get some feedback on.
Report - Optics - Newton's Rings
Essay - Navigation by Polarised Light
Snooker, a-team bridge/cliff , light shimmering of the Dee at Banchory
The snooker picture is a 1.5s exposure of a break which shows the nearly elastic collisions of snooker balls.
The light shimmering of the River Dee at Banchory is a lovely photograph with the Sun setting just at the top left of centre. The light reflection at a wide range of distance on the river shows the randomness and continuity of the waves that reflect the light upwards towards the camera.
The A-team video cliff demonstrates easily how cliffs can be supported moving out over the cliff base. It also shows how and why briges, especially stone ones like the majority of brigdes over the river dee, have arches which is a very simple property of static equilibrium.
The Future
Who knows how far cameras will advance in the next hundred years. In Star Trek, they have holocameras that when a picture is taken it details all your features height, weight etc and from that can generate a life size 3d interactive hologram of the person or place. Will it take 400 years to make holocameras?
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Garry Angus u01gwa@abdn.ac.uk
Last updated 23th of May 2003
