In the Evening News of Lincoln Nebraska, November 1895 the foundations were laid for possibly the greatest lie of the twentieth century. A simple statement was made, the camera cannot lie. That supposed fact has since been popularized as The camera cannot lie and repeated so often that its original use is now very hard to trace.
Why then, is that such a great lie?
Firstly it could easily be argued that the camera is actually incapable of telling the truth, but mainly it is such a good lie because, in spite of its absolute untruth, it has been almost unquestioningly accepted as a great truth by most of the population of the world for over a hundred years.
A camera is only a device for recording light. Some cameras use a photo chemical reaction and others use a photo electric reaction but the principles are the same.
Lets look at the some of the factors that affect the veracity of the photographic image.
1. The camera - The optical characteristics and the mechanical properties of the shutter. *
2. The recording media - The type of film or electronic light sensor.*
3. The camera settings - The exposure and the selection of shutter speed, aperture and focus point.*
4. The viewpoint - The cameras position and direction.*
5. Essential post production - The film processing, Raw conversion.*
6. Non essential post production - Contrast management, colour balance, cropping and creative processing.*
7. Output - Printing, projection, file format, colour management.*
All of these factors have a direct effect on the resulting image and therefore they cannot all be true to the original scene. All of this also assumes that our cameras and lenses are theoretically perfect, which as any engineer can tell you can never actually be true.
Factors 1 to 4 are all set at the time of taking the picture, 5 to 7 occur after the initial recording stage. 1 and perhaps 2 are beyond the control of the photographer. 3 to 7 are potentially completely under their control.
Of all these factors, one sub set, creative processing, is probably the most contentious because with the advent of programs like PhotoShop it is commonly believed that a sows ear can be made to look like a silk purse.
However there is one other factor that dictates the essential truth behind any photographic image.
8. The Photographer Skill, intent and integrity.
A skillful photographer understands how these factors can affect an image and can manipulate them in order to best achieve his intent.
The intent in this case is to produce the image that the photographer wishes to create.
The truth of that image is ultimately determined by the photographers integrity.
If a skilled photographer wants to produce a true representation of the scene before them, then they will try to use their skill to bring that about. If they want to produce an image that distorts the truth they are equally capable of doing that too.
In the end it is the skilled photographer who is most able to create a picture that is like the scene or subject they witnessed as they are the one that actually saw it.
As the viewer we simply have to ask ourselves, do we trust the integrity of the photographer or not?
*Non essential reading. (Technical notes for those people who want to know a bit more about how it works.)
*Note 1. Camera. First let us just examine the light that it is being recorded. The light has to be focused onto the light sensitive area using either a pin hole or a lens of some kind. Both of these contrivances affect the quality of the light that falls onto the recording medium and render the latent image in different ways. A pinhole for example will produce very small circular dots of light whereas a lens produces a range between sharp focused dots and larger circles, these are known as circles of confusion and they vary according to how near or far the object being recorded is from the actual plane of focus. The practical upshot of this is something commonly called depth of field, which means that in front of and beyond the object in focus there is an area that is also apparently sharp that fades into areas that are out of focus.
These differences occur because the recording medium is flat and is trying to record light that is reflecting from objects in a three dimensional world. The human eye focuses on the world in a way that is neither quite like the pinhole or a camera with a lens, but even the image we see is just our brains interpretation of the light that hits our retinas.
To control the time the medium is exposed to the light, camera engineers designed various devices commonly referred to as shutters some of these shutters open like an iris and others use a traveling vertical or horizontal curtain to achieve their objective but all of these methods do have differing effects upon the way the latent image is recorded.
Our eyes see a continually moving image whereas a camera records a finite interval and produces a frozen image of the whole of that interval.
*Note 2. Media. This is a complicated area with two main types but also lots of sub types to consider.
Film. Photographers using film have a choice of colour or monochrome, positive or negative film types. Positive films produce an image for projection in one processing step (Think slides.) and negative films require extra steps and more processing to produce a final image (Think prints).
Additionally, the photographer may choose different sensitivities of film and different brands both of which will produce different types of result.
In general, films that are more sensitive use larger clumps of silver halides in their makeup and result in images that appear more grainy. Each manufacturer makes films with qualities designed to appeal to their majority customer base.
Digital sensors. There are different types of digital sensor, CCD, CMOS and Foveon, all of which work in different ways and produce slightly different results. A digital sensor does not directly produce an image but creates a description of an image in digital format (Sometimes referred to as a raw file.)
This raw description has to be converted into one of the commonly used file formats, such as JPG or TIFF, which can be displayed as an image. Sometimes that is done in a raw converter program (See note 5.) but often this is done by a computer chip within the camera with no input from the photographer.
This conversion affects the end result almost as much as the exposure stage and if in camera, is done according to pre-programmed parameters set down by the manufacturers of the camera. Two different camera models, pointed at the same subject at the same time can produce widely different results. Again, each manufacturer makes cameras with qualities designed to appeal to their majority customer base.
The apparent sensitivity of a digital sensor can be adjusted to some degree by amplifying the signal between the sensor and the processor but in practice this introduces signal noise (random variations of pixel tone.) which reduces the quality of the image and makes it appear grainy.
*Note 3. Camera settings. This is the area most people are aware of affecting the image, for the simple reason that if it is too far out, the image will either be too dark or too light.
Exposure is simply the amount of light that hits the recording media. This is initially a result of the subject brightness range, but can also be affected by altering the length of time the recording medium is exposed to the light and also by reducing the light that passes through the lens.
To increase the apparent depth of field, early camera makers incorporated a range of holes in metal plates, called stops, to reduce the size of the circles of confusion but which also reduced the amount of light falling on the recording medium. These days instead of fixed stops, most lenses incorporate a variable iris or aperture that does the same job with more finesse. Often, closing this aperture to reduce the light entering through the lens is referred to as stopping down the lens.
The length of time the media is exposed to the light is controlled by the shutter but this has a direct effect on the image. For a start, if the exposure is long the subject or the camera may move while the shutter is open resulting in picture blur. If the exposure is very short a moving subject may be frozen in a way that our normal human perception would not normally be able to see.
The total amount of exposure can be set by the photographer but is often set automatically using an interpretation of light measured by the cameras light meter. Metering is a complex issue but usually boils down to comparing the incoming light to an average subject which is assumed to be 18% grey.
Unfortunately, or perhaps fortunately, the world is not 18% grey but is made up of light bits and dark bits of many different colours. Such a light meter reading is inevitably going to be a compromise and may result in an image that looks very little like the original scene.
*Note 4. Viewpoint. By selecting the position the camera is placed and the direction it is pointed, the photographer can include or exclude different parts of the scene or subject from the picture area.
The contents of the picture are often the only things we have to give us the context of the image we are viewing, so the position of those objects in the frame also have a huge bearing on our understanding of what is happening in a picture.
This is a very powerful tool for the photographer to communicate the message that they wish the viewer to receive.
*Note 5. Essential post production. Films need to be processed to turn the latent image created by the exposure into something that we can see.
Positive film does not allow much changing of the result after the exposure apart from pushing or pulling the development to increase or decrease the effective sensitivity of the film.
Negative film sent to a commercial laboratory will be processed and then printed or digitized using computer controlled equipment designed to produce an average type of result.
Photographers preferring more control over their images, traditionally processed negative films by hand and printed them in their own darkrooms to produce a more customized end result.
As mentioned in note 2. A digital sensor does not directly produce an image but creates a description of an image in digital format. The output of a digital sensor needs to be translated into a format that can actually be displayed or printed. This can be done in camera but most skilled photographers choose to do this externally in a computer using a Raw file converter program which gives them more control over the light balance, tonal range and sharpness of the converted image.
*Note 6. Once the image has been processed, either chemically or digitally the photographer can then choose whether or not to apply any extra processing. This is the stage that often lifts an average snapshot into a good photograph.
In the darkroom, a traditional photographer would use dodging and burning techniques to achieve a better balance of tones and perhaps use toning techniques to enhance the pictorial qualities of the image. This is the type of work done by photographic artists like Ansel Adams.
A digital photographer replaces the darkroom with a computer and a program like PhotoShop to apply dodging and burning techniques in order to achieve a better balance of tones and perhaps use toning techniques to enhance the pictorial qualities of the image. This of course will be called cheating.
Either of these photographers could take separate images and combine them in the darkroom or the computer to make composite images for creative purposes but again, one will be applauded for their skill and the other will be called a cheat.
*Note 7. Output . A photograph needs to be outputted somehow. Printing may actually be the last stage in that process but for many images they will also need to be prepared for use on the internet, lectures, presentations or publication. All of these outputs require special treatment which may be as simple as cropping and resizing to preparing colour separations for reproduction.
Needless to say all these processes are capable of altering the appearance of the image greatly.
So who says the camera never lies?