SHARPER IMAGE

Dick Pountain/14 February 2009 15:26/Idealog 175

I've just paid a visit to the stunning Byzantium exhibition at the Royal Academy where the artefacts that most captured my attention were a small ceramic bowl with a delightful smiling fish design and a silver-framed diptych from 14th century Constantinople, consisting of two book-sized panels bearing twelve small pictures like a strip cartoon. These pictures depict various church celebrations, and as well as being beautifully drawn and composed they have an indefinable quality of sharpness with muted yet still vivid colours, quite unlike a painting. On closer inspection it turned out they were micro mosaics, made by assembling tiny beads, no larger than grains of coarse sand, of coloured stone, glass, copper, gold and eggshell. These beads were assembled in a more or less linear grid, so what I was looking at was one of the earliest true digital images, with a resolution not far below that of a computer screen. The rendering engine was a human brain, a pair of sorely-overtaxed human eyes and ten almost-unbelievably dextrous human fingers, equipped with the finest of tweezers rather than a graphics processing chip.

Why would anyone choose such a fantastically difficult medium in preference to paintbrush and paper? One reason would have been permanence: those inorganic materials resist fading and wear and look just as good in 2009 as they did back in 13-something. Another reason would no doubt be that the very tedium and strain was experienced as spiritual exercise, a proof of devotion. But I'd like to think that elusive sharpness of the final product was a pure aesthetic reason in itself. That's certainly the reason that I find myself more and more drawn to digitally processing the photographs I take.

I've documented my enthusiasm for Flickr in this column often before and won't harp on it further except to say that I'm still hooked. I seem to have drifted into a subculture, possibly a minority but a growing one, that believes in using all digital means available to achieve the image that most pleases us - as opposed to those who seek authenticity, who frown on even cropping a picture let alone Photoshopping it (the most extreme insist on black-and-white over colour). I bear them no ill-will and might one day, on a whim, swap sides and join their ranks, but right now I'm in love with HDR.

I've assembled a toolkit of software that works for me at very little cost: Photomatix Pro (the most expensive item) for creating HDR images; NeatImage for sharpening and noise-filtering; PaintShop Pro version 6, which I've used for years in preference to Photoshop (too slow) or even subsequent versions of itself; and Picasa 3 for retouching because I prefer its Tuning controls to anything else I've tried. I no longer only apply processing to rescue images that aren't good enough: even a good photo may yield a better one with judicious cropping and subtly-applied HDR.

Pictures whose content or composition I like but are poorly exposed can sometimes be made more arresting by turning them into "fake paintings", using a whole panoply of techniques including posterisation and solarisation, over-filtering, unsharp-masking and combining different versions using layer blend modes. I've perfected a semi-hypnotic cycle of operations in which I combine two layers by, say, Luminance, then merge them down to one, copy to the clipboard, revert the file, paste as new layer, and so on for dozens or scores of operations until I see something that looks right. My favourite so far is a self-portrait in the style of a 1960s Mao poster which you can see at http://farm4.static.flickr.com/3040/3026961785_df6231ff27_o.jpg.

HDR works by combining several different exposures of the same scene (taken from a tripod) using software on a PC that mathematical transforms them to capture all detail from the darkest and lightest areas: it increases dynamic range so far that the result can't be reproduced on paper or screen and must be tone-mapped back down to viewability. It's very CPU intensive and combining five or more hi-res shots may take several minutes even on a core-duo. Ideally HDR requires a digital camera with automatic bracketing to get a sequence of evenly-spaced exposures.

It's definitely the most controversial of all manipulation techniques because when used without taste HDR produces effects equivalent to the nekkid women, skulls and flames that deface so many hot-rod cars and motorcycles. The combination of too much HDR, over-sharpening and over-saturation is a common sight on Flickr nowadays, a sort of Bacardi-Advert-on-Acid look that's so offensive to purists that many groups ban the technique outright. I regularly post to a group called Realistic HDR that permits only so much processing as is undetectable (no haloes) but gives the subject a slightly surreal edge.

And that edge is the joy of HDR, like an extra lens in your bag that captures the "expectant" look the world has when you're in a certain receptive mood. In that sense it is like a drug, counterfeiting a mood that doesn't naturally occur often enough. By increasing the dynamic range of a scene beyond not only what the sensor in your camera can handle but also beyond the normal human eye, HDR lets you see just for a moment like an eagle or a panther...