The truth is out there ... somewhere

Agent Scully - could this be the truth at last? Go on - play the theme music. Duddlee Da Da Da .... Dee Da Doo Da ....

Among the macho amateur photographer fraternity is an endearing belief that what comes directly out of the camera is really the truth. What happens after that, presumably carried out by fast talking people with slicked back hair, white shoes, sunglasses, loud jewellery and pink suits (with the aid of computers and Photoshop) is some kind of DISTORTION of the truth. "Let's expose these deceitful Photoshop confidence tricksters who represent their doubtful alchemy as the REAL truth. Harrumph!"

In the words of the immortal Thadeus D. Hoppenheimer ... "Give me a break".

If we are going to expose something, let's expose, once and for all, this notion that what comes directly out of a digital camera is really the pure unsullied truth and that post processing is the instrument of its pollution.

Let's leave aside (for the present) the question of correct shutter speed and aperture. Let us assume that our macho shooter (hereafter known as MS) somehow manages to get the image exposure settings spot on every time in his search for the truth. Such a feat would be truly incredible ... BUT ... let's assume it anyway. We'll come back to the metering issue another time.

We'd better define what "the truth" means before moving on. In the absence of something more philosophically rigorous, let's say that MS's truth is "what he originally saw before deciding to take a picture". Okay, let's go with that.

MS takes a picture with his digital camera. It is the best exposure that can be expected. He examines it in his computer, prints it out on his dot matrix printer or else takes it to the lab at K-mart to get a print made. MS doesn't believe in "cheating" with Photoshop and so we know that he didn't shoot it as a RAW file (which requires post processing). Nor did he intentionally manipulate it in any way with computer software.

Is the image in the print, that he holds in his hand, the truth? Almost certainly not.

His girlfriend, the central subject of the picture was originally some distance away but was brought closer than MS's original natural view by his zoom lens. The image is not what he actually saw with his eyes. By MS's strict standards it must already be an untruth. MS's nice landscape was framed to omit the overflowing rubbish bin just to the left. Untruth. The landscape features a setting sun and the image shows bits of lens flare. Untruth. The trees to the right are actually much darker than MS saw because the bright sun caused the camera's exposure metre to render them in silhouette. Untruth. Good photographer that MS is, he brightened his girl friend's face with fill in flash so that it wouldn't be rendered as a dark outline by the sunset. The result could not possibly have been seen before the decision to shoot was made. By definition it is an untruth.

Once he takes the purist route, MS is immediately in trouble. As soon as a decision to take a picture is made, MS's "untruths" are inevitable. Some arise from the fact that large amounts of the scene he originally saw are inevitably cropped out - either on purpose or because not everything in his field of vision can possibly remain in shot. Some arise because of the inherent limitations of cameras and lenses. When shooting directly into the sun, lens flare is virtually inevitable. Likewise, the dynamic range of a digital sensor is severely limited. Detail will inevitably be lost at either the shadow or highlight end (or both), such that the trees which originally showed green detail are now black outlines. If he was using a fast lens and/or was especially clever, background may be pleasingly reproduced out of focus, bringing the girlfriend's face into sharp relief. It may make a great picture but it "wasn't what MS originally saw". UNTRUTH.

But MS can go forward content in the knowledge that he didn't ... heaven forbid ... "photoshop" it. Of course if MS HAD photoshopped it, he might have been able to remove that untruthful lens flare, restore those untruthful tree silhouettes and retrieve truthful detail in his girlfriend's hair highlights. But let's not worry MS with inconvenient details like that.

The irony of it all is that MS's allegedly unsullied picture has ALREADY been well and truly "photoshopped" in a manner of speaking. Because he didn't shoot RAW, his camera's JPEG firmware has taken it upon itself to process the image in a number of ways.

• The camera has almost certainly artificially sharpened the image. All digital sensors have anti-aliasing filters which blur images slightly to reduce the appearance of pixellation. In producing displayable imagefile formats, pictures are routinely sharpened to some extent.
• The camera has probably enhanced the image colour. Industry research reveals that most people "remember" more colour in a scene than is strictly captured by a digital camera. To deliver a popular colour effect, images are usually auto-processed in-camera to saturate them a little.
• Sometimes at high ISO settings, camera firmware automatically DEsaturates colour in order to minimise noise.
• Depending upon the settings, the firmware will deliver a relatively wide range of contrast values.
• However good the auto-exposure may be, white balance, as determined by camera firmware, is often wildly inaccurate.

The proposition that an image direct from a digital camera is always the inviolate truth is highly questionable at best. Digital cameras and the very notion of image capture are imperfect in themselves. Usually the image "straight out of the camera", has already been processed - often inaccurately. It may be time for MS and all of his ilk to cast aside their comfy delusions.

Whatever the camera does to images can only be controlled imperfectly in the heat of the moment at the actual time of exposure. Camera settings and their effects are crude at best. The whole point of post processing is that image parameters can be adjusted at one's leisure using genuinely fine gradations to arrive at the best approximation of the truth possible.

Is there more to say on this subject? You bet! I am only getting warmed up.

See my work at: www.pbase.com/davidhobbs