Tasty Treatments

Instagram, shmam! Create your own cross-processing using Curves in Photoshop

Colour photography is all about reproducing the colours that were in the original scene - except when it isn’t. It may seem a little perverse if you spend your time trying to capture sharp, detailed, accurate photos, but flaws hold an intense fasci­nation for many people.

The rise of Instagram has made funked-up photos a worldwide craze. People all over have been using this to turn iPhone snaps from regular photos into treated wonders. The number of people using this is said to be near 100 million, which means a hell of a lot of square, oddly coloured images. Don’t get me wrong, Instagram snap photography is fun - I just think it’s also a bit of an odd craze.

Create your own cross-processing using Curves in Photoshop

Before Instagram, Lomography was where the odd stuff was at. The Lomo name - .HOMO in Russian - comes from Leningrad Optical Mechanical Amalgamation. This organisa­tion first produced a camera (a Leica copy) in the 1930s, and the Lomo Kompact Automat, or LC-A - which was a copy of a Japanese camera - arrived in 1982. These Russian-made film cameras were originally intended to be used by every Soviet citizen, but their quirky, imperfect and slightly unpredictable output caught the attention of European hipsters in the early 1990s and they quickly became a cult hit around the world. Today, the lomography.com fan site boasts more than 5,000 photo uploads a day - not bad for a production method that uses old-school film and inconvenient chemical processing.

One technique that crops up with both of these pho­tographic movements is cross-processing - simulated in Instagram, real with Lomography. Cross-processing is a photographic chemical mashup that mucks about with the colours in a photo as the film is developed. More precisely, it involves processing one kind of film in the chemicals meant for a different film. The exact results this gives depends on which kinds of film and chemicals are used, but the most popular one involves putting transpar­ency (slide) film (which is intended for developing in E-6 chemicals) through the C-41 chemicals, which are meant for colour negative film. What this technique typically pro­duces is a green or blue tinge to the deep shadows, reds that look somewhat bruised-purple and a warm yellow cast to highlights. It’s a very striking look, and it’s been used in all kinds of places, from fashion to Hollywood movies.

True confession time: I actually saw some of the film Twilight the other night when it aired on TV. I’m clearly not its target audience, but I was fascinated by the visual style it used. The whole thing - or at least the part I watched - was given a moderate cross-processed treatment; the shadows were a little blueish, skin tones didn’t have much warmth at all and lips were almost the colour of congealed blood. Moody to the extreme, and it suited the story and overall genre perfectly.

It’s not hard to do your own cross-processing. Hang on, let me clarify that: it’s really quite difficult to actually do your own colour developing, but it’s easy to have your film cross­processed for you if you go to a relatively professional photo lab rather than a high-street shop. Shoot on transparency film and process as print, and the job’s done. Or do it the 21st-century way: shoot digital and cross-process your images yourself in Photoshop. Some like the unpredictability of the wet chemical and film method, but I have to admit I prefer having digital control on my side even if it doesn’t have the same kind of instant fun as Instagram.

Cross-processing images in Photoshop is best done in the Curves dialog. It’s a bit opaque, but it’s not really that hard, especially if you spot the Cross Process preset. Pick an image, choose Image > Adjustments > Curves, then just pick it from the Presets menu. Each of the RGB channels is given its own custom ‘curves’ adjustment that boosts or reduces it in the highlights and shadows.

At this point, I’m sure you’ll agree that the effect this preset makes is a bit over the top: bright highlights are ren­dered a bit pink, while skintones and the midtones in general are battered about with rather more green than you proba­bly expected. It isn’t that this effect is incorrect; remember, cross-processing output can be affected by the choice of specific slide film. The issue here is more that it’s a bit heavy-­handed for most serious uses.

Fixing this is quite simple: in the Curves dialog, switch the Channel pop-up menu from RGB to Green and drag the right- hand point up to the top-right corner of the Curves histogram box. That fixes the over-pinkness of the brightest points, and you may like the in-yer-face quality of the rest of the settings. If you’d rather have something a little less glaringly treated, you’ll need to come up with different red, green and blue curves. I’ve saved a particular set of curves as my standard lightweight cross-processing preset. It’s a bit difficult to list the values for this so, instead, you can download the preset from panoramaphotographer.com/tools and load it in the Curves dialog. Photoshop’s default location for Curves presets is in ~/Library/Application Support/Adobe/Adobe Photoshop CS6/Presets/Curves (or the equivalent for earlier CS ver­sions), but you can keep them wherever you like. Alternatively, look at the red, green and blue curve lines, and the slight tweak to the composite RGB curve, in the middle screengrab on the previous page and remake them yourself. If you come up with something different that you like, don’t forget to save it as a preset so you can reapply it without having to make it from scratch each time.

Curses in Photoshop CS6

Cross-processing isn’t the only mistake-based effect the film world has. Redscale is a lesser-known trick that comes from loading colour film back to front into the camera so the colour layers receive light in the opposite order to normal. With the red layer getting the light first, this is what gets recorded most, and blue gets the least light. As with cross-pro­cessing the results can vary, but they’ll always have a strong red bias. The gentler versions of this look are reminiscent of old photos that have been in sunlight, where the blue often fades first, although this effect doesn’t have the same loss of contrast. Stronger redscale effects are more dramatic, to the point of looking like garish mistakes when taken to extreme.

Want to try redscaling? There’s no Adobe preset for redscale, but faking this is pretty simple, as you’re really just simulating the over-recording of red, slightly underdoing the green and removing quite a lot of the blue. Grab my one-stop redscale curves preset from the same place as the cross-pro­cessing file and see what you think. This is definitely a more obvious effect, but it’s based on a traditional - if somewhat unorthodox - photographic method. And the best part of doing these things digitally afterwards is that I get to have my cake and eat it: I can use a shot untreated if I prefer and I can try different settings to find the best result, because I haven’t committed anything at the moment of taking the shot.

The original picture

This shot of surfers at Polzeath could do with a bit of extra pizazz

Photoshop default

This effect is pretty garish and too over-the-top for most uses, so it’s best to tweak the channels

Lightweight cross-process

These custom red, green and blue curves produce a more subtle effect

Redscaling

Gentle redscaling look a bit like old photos that have faded in sunlight, where the blue usually fades first