How to simulate cross-processing in digital photography

The term “cross-processing” is a bit uninformative and dubious in these digital days. It stems from the old days of film photography, and many digital photographers of today (and surely also many of those who has converted from film) do not know what it is. Not surprising, really, since most of us never processed our own color films.

What is cross-processing?

Originally, cross-processing involved using a chemical liquid other than the liquid meant for the type of film being processed. Most notably, the technique was used to process slide film with the chemicals made for print film. The result was photos with stark contrast and a little strange colors, often with a bluish or greenish cast. Cross-processing is also strongly associated with the old Russian LOMO camera, a low quality camera known for its unpredictable results. LOMO owners usually cross-processed their slide film in chemicals for 35mm film.

Today, anyone (that means YOU!) can cross-process their photos. What’s even better: it’s actually relatively simple! I will guide you through the process using Photoshop. I have to use my old CS2 version since Elements 8 for Mac does not include the Curves tool (bummer).

How to cross-process digitally

How much work you do, and how hard you adjust will always depend on how you want the resulting image to look. In this tutorial I will strive for a “LOMO-look”, so the adjustments will be fairly thorough. If you want a more subtle change, feel free to downscale my adjustments a little. Trial and error is the key anyway.

We’ll start by increasing global contrast. If you chose a high-contrast photo, you may choose to skip this step.

Open your desired photo and create a new curves layer (Layer -> New adjustment layer… -> Curves). I name this layer “Contrast”.

In the Curves window, create a shallow S-curve to increase overall contrast:

Now, repeat the process of creating another curves adjustment layer. Name this layer “Color”.

In the “Channel” drop down where it says “RGB” you now choose “Red”. Adjust the curve like you did in the last step with a classic S-curve.

Change the channel to “Green” and repeat the previous step.

Lastly, for the channel “Blue” you create a reverse S-curve by lowering the highlights and heightening the shadows:

The image is now cross-processed, but we still need to make some adjustments to make it more “LOMO-like”.

LOMOification – Sharpening

We’ll start by sharpening the image, creating a “harsher” look.

Start by merging your layers (Layer -> Merge visible if you’re using CS2).

Next, convert the image to Lab color (Image -> Mode -> Lab color).

Now, open the Channels palette and click on “Lightness”. The lightness channel is now the only selected channel:

Use the Unsharp mask to sharpen the image (Filter -> Sharpen -> Unsharp mask…). I usually go for an amount of 40% and a radius of 40 pixels, and a threshold of 0 levels. Try different settings and find the look you like.

Change back to RGB-mode (Image -> Mode ->RGB Color).

To make the photo even more “LOMOified”, you might want to add a vignette. The LOMO is (in)famous for generating quite a bit of vignetting. I must admit that it has its charm. So if you want, go ahead and add a vignette as a last step!

LOMOification – Adding a vignettte

There are several ways of creating a vignette in Photoshop. I will show you my preferred method.

Start by duplicating your background layer (Layer -> Duplicate layer). I name my layer “Vignette”.

With this layer selected, choose the “Elliptical Marquee Tool”. Place the marker about 1cm down and right of the top left corner, click and drag the ellipse all the way down to 1cm above and left of the bottom right corner. The ellipse will now cover most of the image, having a margin of 1cm to all sides.

Next, click the “Add layer mask” icon at the bottom of the Layers palette (the grey square with a white circle inside). On the Vignette layer in the Layers palette, a Layer mask thumbnail appears (and yes, the ellipse marquee disappears). Make sure the Layer mask thumbnail is selected by clicking it.

To get a better visual response when doing this step, I prefer to hide the background layer temporarily (clicking the eye at the far left of the layer in the Layers palette).

Create a gaussian blur (Filter -> Blur -> Gaussian blur…). Set the amount of blur you want. I feel that around 30 pixels are fine. Click OK.

Now do the following: Unhide the background layer by clicking in the empty box where you clicked the eye a few moments ago. The image now looks just like it did before we started creating a vignette.

Select the background layer by clicking on it (important!).

Create a new fill layer (Layer -> New Fill Layer -> Solid color…). Call the layer whatever you want, or accept the default.

Click OK, and a Color Picker appears. Pick a totally black color and click OK. Now, in the Layers palette, click the Opacity field and reduce opacity to your desire. I usually go for an opacity between 40 and 50%.

And you’re done!

Compare the original with the cross-processed one. Like the effect?

Not all photos respond equally well to cross-processing. Trial and error is again the key. With more experience, you will learn to see which of your photos that may benefit of cross-processing.

Afternote – How much to adjust?

There is no right or wrong here, as this depends on the effect you want to achieve and the photo in question. Both the light, mood and colors of a photo will affect the adjustment amount. The amount shown on the screenshots here is a guide. Play around a little and decide what works best for you.

Was this tutorial easy to follow? Was anything unclear? Please leave a comment and I will do my best to clarify!

As always, we would love it if you share your photos after following this tutorial. Hope to see you in the comments section!

If you liked this post, you may also like:

1. HDR (High Dynamic Range) photography – An introduction
2. How to create a black&white image with selective colors in Photoshop