Rendering an Image

A digital photograph is a two-dimensional representation of a “representation of presence,” as Roland Barthes suggests in “Camera Lucida.” It is a result of an optical and electrical process that creates a bit map that is first revealed on a backlit computer screen. This initial process of rendering the image is handled by a fixed algorithm written first by the engineers that created the camera and second by the engineers who wrote the software for the post-processing software. In other words, the image is not therefore an accurate representation of a place, person or event it has been manipulated extensively as it travelled from the camera into the computer or iPhone screen. Every camera and post-processing software will create a different result some with subtle differences and others with significant differences. What is most important to an artist is that the image truly captures the experience of being present when they were drawn into framing the scene with their camera. When one uses a photograph to create an artistic representation of one’s presence it is important how this image is rendered, and in many cases what the camera and viewing software initially produce is not an accurate reflection of the experience.

Barthes suggests that a photograph in Latin would be expressed as imago (image revealed), lucis (extracted), opera (mounted) and expressa (expressed). I think this is a useful taxonomy, of the four stages involved in photography if not all art forms. First the capturing of this image, second the rendering of the image, third the presentation of the image and finally the venue in which it is viewed. During all four stages, consideration has to be given to how the image will be finally expressed.

These stages or process applies to most artistic processes, take for example the paintings of E. J. Hughes, a contemporary of Emily Carr and the group of Seven. You can see from the process he follows that he begins with capturing and framing the scene which is done by eye, and a pencil sketch. In the pencil sketch, he records the shapes and colours of the scene before him. However the colours he notes relate to the palette he will use when rendering the image, rather than the actual colours he is seeing. So he is already in the process of translating the colours into the media he is going to use to render the image.

Mt. Cheam and the Fraser River, 1958 mural study pencil by EJ Hughes.

You can see from the paint how he renders the colours and shapes into the finished painting to recreate a record of his presence in this scene into its final presentation. In photographic terms, he has sharpened the shadows, contrasted the colour tones, altered the pallette to remove conflicting colours and altered the dynamic range of the image.

The second sketch is more complex recording a lot more information about how to translate the colours and details in the scene.

Eagle Pass at Revelstoke,(1958) Pencil Sketch Study for painting by EJ Hughes

Again he takes the information from the sketch and renders the image into its final presentation.

1961, Oil Painting by EJ Hughes

In photography you would start at the same point that Hughes did by finding and framing an image but instead of sketching it, and making a notation of the colours, the digital camera records a facsimile of the scene with an RGB representation of the colours. The resulting photograph is the photographer’s sketch. A photographer may also take numerous captures, in a different light. Like Hughes, once the photographer has returned to his studio and opened the sketch in post-processing software the process of trying to reconcile the photographic sketch with their experience begins.

The following chart illustrates the limitations of a camera’s ability to record colour in RGB, the three colours it uses to create all colours, and how it differs from what the eye sees. As you can see from the diagram the range of colours in RGB is not what the eye is seeing. So like Hughes and his oil pigment paints, the photograph has to consider the palette available in order to render the scene as they had experienced it. In addition to this problem, the photographer also has to consider presentation, when the image is printed it will be in CMYK, which has a wider but different range of colours.

The RAW RGB photograph now has to be rendered in post-processing software. This can be a simple process or highly complex depending on the photographer. The two images below illustrate the simple rendering of an image. The image was captured during a warm spring afternoon with the sun streaming through various areas of the park. What drew me to the image was the light and the contrast between the large trees and the people in the park.

In the RAW image you can see the algorithm struggle unsuccessfully with the dynamic range of the images causing the trees to go far to dark and the light and colour in the scene was muted.

Canopy (RAW), Edward Peck,

The rendered image below is a much more accurate rendering of the scene I experience. In order to do this I had to correct the highlights to bring back the blueness of the sky seen through the trees canopy, that had been lost. Also the shadows needed to be adjusted to bring back the textures in the trunks tree trunks. A simple adjustment to the whites brought back the light falling in the scene beyond the trees. In addition to these adjustments the colours had been muted or dulled down by the camera’s software, so colour had to brought back as well balanced. The effect of this was to restore the relationship between the trees in the foreground with the individuals in the middle ground that had been lost. Finally the framing was altered as the camera has a fixed aspect ratio that needed to be adjusted.

Canopy (Rendered), Edward Peck,

These are very simple adjustments, perhaps not as great as some photographers might make and certainly not a great as Hughes made to the paintings above. A good illustration of a more dynamically rendered image is Jim Friesen’s Pitt River I. Here the photographer has rendered the image to bring out the dynamic nature of the clouds and there reflect that drew him to capture this image. He has achieved this by reducing the impact of the colours in the forest and foreground foliage and enhancing the refections.

Pitt River I, Courtesy of Jim Friesen,

Jim was kind enough to share the capture he began with (below) and tells me this is the out of camera shot with just some basic processing applied to it. You can see the experience it expresses is quite different.

Pitt River I, Courtesy of Jim Friesen, with only basic processing applied to the image

So like Hughes the sketching and rendering process are both important to artists like him and photographers whose artistry is to bring back the sense of presence that was felt in the scene they were capturing.


Barthes, Roland. (1981) Camera Lucida: Reflections on Photography (translated by Richard Howard) Hill and Wang: New York.

Amos, Robert. (2019) E. J. Hughes: Paints British Columbia. Touchwood: Victoria, BC.

Friesen, Jim, Pitt River I,

One thought on “Rendering an Image

  1. Jim Friesen

    I realize I must have cropped the basic processing version and made a separate copy for the final edit version.

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