Digital Manipulation

Article by Ron Bigelow

www.ronbigelow.com

Let me start off by stating that this article was motivated by a real experience. One day, I ran across a photographer’s web site. This photographer strongly emphasized how his images were superior because he did not digitally manipulate them. However, I later saw how he manipulated the contrast of his prints by dodging and burning the prints in the dark room.

At first, I was a bit amused. Later on, my initial amusement was replaced by a realization that this was just one example of a real issue that faces us in the digital age – the issue of digital manipulation. When I show an individual my images for the first time, the initial questions that I usually get are, “Were these images manipulated?” and “Did it really look like that?” My answer to both questions is yes.

These questions belie a belief by many people, including some photographers, that the camera does not lie -- what the camera captures is reality. The first corollary is that, after capture, digital photographers alter reality by digital manipulation, thus, creating something that is not true to reality. The second corollary is that those photographers that do not digitally edit their images have images that are more true to reality. The purpose of this article is to examine these beliefs.

Unavoidable Capture Manipulation

During the capture process, the camera, whether film or digital, manipulates reality. Film cameras are primarily mechanical and optical devices (with some electronics to aid the process of capturing an image) that have physical limitations that prevent the cameras from exactly capturing reality. Digital cameras are electronic and optical devices that also have limitations which prevent them from exactly capturing reality.

Field of View: When a photographer views a scene, the photographer has a very wide field of view. Often, a photographer will turn around and view the entire area in order to examine the lighting, possible compositions, and other factors that might affect the image. This results in a wide view of the area, up to 360 degrees. The camera has a very limited field of view, generally a rectangle, which considerably restricts that which is seen in the final image.

Dynamic range: The dynamic range of the outdoors is very wide. The light of a normal day might have a dynamic range of around ten stops. Most cameras/films have a much narrower dynamic range. Most print film has a dynamic range of around five stops. Slide film's dynamic range is about three stops. Most DSLRs have a dynamic range of around five stops, maybe a bit more. There are some exceptions. Some black and white films have a very wide dynamic range that approximates the dynamic range of the outdoors. Similarly, some medium format digital cameras also have a very wide dynamic range. However, most photographers today are shooting color with something other than a medium format digital camera. Thus, the capture process forces a cropping of detail in many images. This causes detail to be lost in the highlights, the shadows, or both.

Color Space: The outdoors is composed of a huge palette of colors. Cameras can not capture all of these colors. Thus, the colors are manipulated during the capture process to fit into the palette of colors that the camera and capture materials (i.e. film) can produce.

White Balance: There is rarely a perfect white balance match between all of the light in a scene and the camera/capture materials. Any particular film is balanced for one color of light (expressed in degrees Kelvin). In most situations, there is not an absolutely perfect match between the temperature of the light and the temperature for which the film is rated. Filters can sometimes help produce a better match. However, there is rarely a perfect match. Thus, all of the colors in the film will be somewhat shifted. Digital has more flexibility. However, the problem still exists even with digital. Auto white balance rarely produces flawless results. If a preset white balance option is chosen, the same situation as with film occurs (i.e., there rarely is a perfect match). Some believe that a custom white balance solves the problem. This is not always the case. If you doubt this, try shooting an image of a beautiful sunset using a custom white balance. The image will have colors that are desaturated and less than pleasing compared to what you saw. Another problem is that scenes generally have light of several different color temperatures. Unfortunately, the camera can be set for only one temperature. For instance, many images have areas of both daylight and deep shadow. Compared to daylight, deep shadows have a bluish tint. If the white balance of the camera is set for the daylight color temperature, the shadows will be recorded with a bluish tint. If the white balance of the camera is set for the shadows, the daylight will appear overly warm. Lastly, the human eye and brain adjust the colors that we see. For example, a person looking at a scene with both well lit and shadow areas will probably not notice the bluish tint in the shadows. This is because the human brain adjusts the colors that we see. On the other hand, a camera will likely record the bluish tint in those same shadows. Thus, the reality that the viewer experienced is manipulated by the camera.

Optical Distortion: No Lens is perfect (e.g. spherical aberration, chromatic aberration, barrel distortion, pincushion distortion, and diffraction). All lenses have design and material limitations. Thus, the camera optics distort (i.e., manipulate) the scene that is captured.

Depth of Field: Due to the fact that the human eye can automatically focus at any point in space, the eye essentially has an unlimited depth of field. This is not true of a lens. Camera lenses can focus only at one point. The areas close to that point will have reasonable sharpness. The farther away from the focus point in an image, the less sharp the areas will appear. Thus, an image of a scene will often have a shallower depth of field that what the photographer saw.

All of these factors alter the reality that a viewer observes. Furthermore, they are unavoidable. While it is true that their effects can sometimes be reduced (e.g. using a better lens to reduce optical distortion or using a wide angle lens to increase depth of field) they can not be completely overcome (e.g., a wide angle lens will increase depth of field, but it will also increase optical distortion). Thus, the camera does not produce an exact replication of what a viewer observes.

Conclusion #1

If you pressed the shutter button, you manipulated what you observed.

Optional Capture Manipulation

Photographers use various pieces of equipment and a multitude of practices when capturing images. Many of these manipulate reality.

Wide Angle Lenses: Wide angle lenses distort perspective  (actually, it is not the lens but the way that it is used that causes the distortion of perspective). Wide angle lenses tend to stretch out scenes making objects that are closer to the camera look larger and objects that are farther away look smaller than they appear to the unaided eye (i.e., without looking through the lens).

Long Lenses: Long lenses also distort perspective. They tend to compress scenes making objects that are closer to the camera look smaller and objects that are farther away look larger than they appear to the unaided eye (again, it is not the lens but the way that it is used that causes the distortion of perspective).

Slow Shutter Speed: Slow shutter speeds can cause an intentional blurring of parts of an image. For instance, landscape photographers often use a slow shutter speed with moving water to produce a dreamy effect.

Fast Shutter Speed: Fast shutter speeds are often used to freeze action. Despite the fact that the human eye does not. For instance, I have seen many images of birds frozen in flight. I have yet to see an actual bird frozen in mid air.

Selective Exposure: Photographers sometimes deliberately manipulate the exposure to create a specific effect (e.g., deliberate overexposure to create a high key effect) even though it alters what was seen.

Selective Depth of Field: Another common technique is to select the aperture to create a selective depth of field to limit the viewers' attention to a specific area. For instance, portrait photographers often use a limited depth of field to blur the background -- even though they can easily see the background with their eyes.

Selective Focusing: In the same vein, photographers often use selective focusing to help direct a viewer's attention to a particular point in the image -- despite the fact that the unaided eye of the photographer does not have selective focus.

Selective Framing: A very common practice is for a photographer to frame an image in such a way as to intentionally exclude items from the image (e.g. a telephone pole or soft drink can). This is just part of good composition. On the other hand, it produces an image that is different than what the photographer saw, thus, causing manipulation.

Filters: Filters are frequently used to alter contrast or color (e.g., polarizers, split neutral density, and color filters). Even thought their use may create an effect different than what was seen by the eye.

Saturated Film: Landscape and nature photographers have been using saturated films for many years to enhance the color of scenes. Even though these films may not match the color saturation seen by the eye.

Flash: Most all photographers have used flash in some of their images (e.g., fill flash). This is done to deliberately increase the amount of light on the scene. While this often produces a much better image, it does so by altering the natural light of the scene -- producing something different that what the photographer saw.

Most, if not all, of these methods are just considered part of the creative process of photography. Most photographers don't stop to think that what they are doing causes manipulation. For example, while I continually hear digital photographers accused of altering reality by adjusting the contrast or color of an image in the computer, I have never heard of an action photographer accused of altering reality when he used a fast shutter speed to freeze motion to produce something that the human eye did not perceive -- even though both photographers altered reality. This leads to the next two conclusions:

Conclusion #2

Much of the equipment and many of the practices that are considered part of the
creative process produce their desired effects by manipulating reality.

Conclusion #3

Much of what we do as photographers isn't even thought of as manipulation -- despite the fact that it alters reality.

Editing Manipulation

Since most people in the digital age tend to associate image editing with manipulation, I am almost tempted to ignore this type of manipulation. However, I will not ignore it for one reason: some photographers tend to view manipulation in the dark room (e.g., burning and dodging) as somehow acceptable and natural while they view digital manipulation as a process that produces an altered image. The fact is that editing, done in either the darkroom or the computer, causes manipulation of the imagery that is being worked. This leads to conclusion #4:

Conclusion #4

Procedures carried out in a darkroom to alter tone, color, or other aspects of an image
are no less manipulative than those carried out in a computer.

Output Manipulation

Just as manipulation during the capture process is unavoidable, manipulation during the output process is also unavoidable. Output devices (e.g., printers and monitors) have limitations that prevent them from producing exact duplicates of reality (even if reality had been captured perfectly which, by now, you know is impossible).

Dynamic Range: Often, the dynamic range of the output device is less than that of both the original scene and the image in the computer that was taken from the scene. Manipulation is required to compress the dynamic range of the image into the dynamic range of the output device.

Color Space: Similarly, the color space of an output device is often smaller than that of both the original scene and the image in the computer. Thus, some colors will be manipulated in order to fit the colors in the image into the palette of colors that the output device can produce.

White Point: Part of the color space issue is that output devices are limited in how pure a white they can produce. For instance, a printing paper can not produce a white that is any brighter than the white of the paper. Thus, when printing, a pure white of a scene will become a paper white in a final print -- even though the paper white is not pure white.

Consequently, the output process manipulates images. This leads to conclusion #5.

Conclusion #5

If you outputted an image, you manipulated reality.

An Important Insight

All of the conclusions so far should lead to an important, overall conclusion:

Conclusion #6

It is impossible to capture or output an image without manipulating reality.

To me, this is a very important conclusion. It points out the fallacy of those photographers (such as the one mentioned at the beginning of the article) that claim that their images accurately represent reality because the images were not manipulated in the computer. The fact is that no photographs exactly represent reality. Rather, they create an interpretation of reality that is bound by the limitations of the mechanical, optical, electronic, and chemical processes that are utilized to capture, process, and output the images.

Digital Manipulation and Reality

Of course, with digital, manipulation is much easier than with non-digital processes. This leads people to be dubious about the veracity of digital images. Unfortunately, the general public, and some photographers, are less than knowledgeable about digital manipulation and tend to think of all digital manipulation as a bad thing that creates falsified images. This is a rather simplistic and mistaken view. In reality, not all digital manipulation is the same. To understand digital manipulation, it is necessary to understand that there are different types of digital manipulation. For the purposes of this article, digital manipulation will be broken into four categories:

Digital Manipulation and Falsified Images

Unfortunately, this is the category that many people think of when they think of digital manipulation. In this category, two things happen. First, a photographer digitally manipulates an image to create a final image that does not come close to representing what the photographer saw when the image was captured. Second, the photographer either attempts to hide the truth about the manipulation or fails to inform the viewers of the image about the manipulation. Thus, the viewers are lead to believe that they are seeing something that represents reality -- when, in fact, no such reality existed at the time of capture. A case in point would be a photographer who digitally adds a dramatic sunset to a beach scene, which had an uninteresting sunset, in order to produce a dramatic, final image. The photographer then leads people to believe that they are looking at a scene that actually occurred.

This type of manipulation is inexcusable and leads to the doubts that many people have about digital images.

Conclusion #7

Using digital manipulation to create an image that appears to be a representation of reality,
when it is not, without informing the viewers of the manipulation is inexcusable.

Digital Manipulation and Photographic Art

Sometimes, a photographer alters an image in such a way as to produce an image that is different than what was observed in some substantial way, but the photographer is not attempting to mislead the public. Actually, the photographer is not attempting to express a literal version of reality. Rather, the photographer is expressing her vision or an idealized version of reality. As long as the photographer is open about what has been done to the image, this is perfectly acceptable. This is no different than what a person that produces an oil painting of the scene would do. After all, we don't chastise an individual that produced an oil painting because she didn't show the empty beer bottles and soda cans that were in a scene that she painted.

Conclusion #8

Using digital manipulation to create photographic art is a great use of digital manipulation.

Digital Manipulation and Normal Processing

This is the category into which most digital manipulation falls. In this category, a photographer uses the computer to alter the tone, contrast, hue, saturation, or other aspects of an image to create a final output that represents what the photographer experienced. This is the category where a lot of the confusion about digital manipulation occurs. Some people tend to think that, because the photographer manipulated what was captured by camera, that the image has been falsified. However, as long as a photographer is attempting to recreate an accurate representation of what was experienced, this is a valid process even though the image was manipulated. Some examples may help clarify the issue.

Conclusion #9

Using digital manipulation to create what the photographer experienced is no less valid a process than
the non-digital techniques that photographers have used for decades to produce non-digital effects.

The sad thing is how little this is understood by some photographers. These photographers will think nothing of dodging an image in the darkroom. However, these same photographers will criticize someone for altering the contrast of an image in a computer.

Digital Manipulation and Our Brains

Our eyes and brain alter what we see. For instance, our brain affects the colors that we perceive. We may see colors as being more or less saturated than the actual saturation of the light. Furthermore, a hue that we see may be different than that of the actual light (if you doubt this, consider that the fluorescent office lights that many of us work under have a tint, but we don't walk around all day noticing that tint in everything we see in the office). This leads to a very important conclusion:

 

Conclusion #10

Because our eyes and brain alter what we see, it is often necessary to manipulate what the
camera captured in order to create an image that shows what we experienced.

Correcting Limitations of the Capture Process

Digital manipulation can correct limitations of the capture process. For instance, two or more exposures of a scene can be digitally combined to capture the entire dynamic range of a scene that could not be captured in a single exposure. This would produce an image that more closely represented what the photographer saw than an image from a single exposure (which would have clipped some of the tones). In a similar vein, two or more images, each focused at a different distance, can be digitally combined to increase the depth of field. This would produce an image that has a depth of field closer to what the photographer saw than an image from a single shot (which would have areas of soft focus due to a more limited depth of field).

This leads to the last conclusion:

Conclusion #11

Digital manipulation can be used to make images that more closely represent reality than the unedited images.

Summary

Frankly, much of the manipulation that can be done digitally can also be done in a non-digital manner. For years, photographers have:

I have never heard anyone complain about these or other non-digital methods of manipulating images. When the same things are done digitally, someone will complain that the image was digitally manipulated. It would appear that it is not the manipulation that bothers them -- it is the newness of the methods that were used to create the manipulation.

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