You’ve heard of graduated filters, but what about Nik’s Bi-Colour Filters?

Bi-Colour Filters are just one of the Filters in Color Efex, part of the Nik Collection. What they do is apply one color to the top part of the picture and another to the bottom. This might sound like a bit of a cheap novelty, but it’s surprising just how effective this Bi-Colour Filter can be – and how often.

We’ve all got photos, probably hundreds of them, which are just a bit flat. They lack color. You can’t always choose the time of day when you take pictures and sometimes a scene just doesn’t have the vibrancy and color you associate with it. This is exactly where the Bi-Colour filter in Nik Color Efex can step in.

Now you might immediately think of the Cokin graduated filters that were all the rage a few years back and probably make most of us wince now. The Bi-Colour Filter is not like that. First, it offers a choice of colour combinations which can actually work together very effectively. Second, this is digital editing, and far cry from the days where all we did was slap a bit of plastic in front of the camera lens. Now, it’s possible to apply these bi-color effects with a great deal of subtlety and finesse.

You also have to match the filter effect to the subject, of course, so that it enhances the image in a realistic and pleasing way. With this in mind, I chose my shot of the Tokyo skyline at dusk from the top of the Roppongi Hills Mori Tower, as a shot that should have been great – but wasn’t. In fact, the Tokyo skyline didn’t prove to be the saturated neon spectacle I anticipated. It was still beautiful but with a cool, dusk blueness about it.

So just for fun I used the Color Efex Bi-Colour Filter to introduce some of the color I was expected. It’s a bit of a cheat, of course, and doesn’t pay proper respect to this beautiful city, but it does show what this filter can do.

How Nik Color Efex Filters work

1. Nik Color Efex offers both Presets and Filters in its left sidebar. Presets are pre-packaged combinations of different filter effects combined, while Filters are the basic building blocks. You can use Filters individually, and this is often the best way to build a custom effect.
2. Alongside each Filter in the list, you’ll see a small disclosure arrow. If you click on this you’ll see a selection of pre-configured settings for that filter and how they will look on your image. This is a really quick way to get started. You just click on the thumbnail you like and the filter is added to the filter stack over in the right sidebar.
3. When you move the mouse over the Filter you want in the left sidebar you will see a ‘+’ button. When you click on this, the Filter is added to the filter stack in the right sidebar, in addition to any others you’ve already added. If you don’t click the ‘+’ button, the Filter will replace whatever Filter is currently active in the right sidebar. Just remember – click to replace, click ‘+’ to add.

Nik Color Efex Bi-Colour Filter settings

The secret with this filter is to choose a sympathetic color combination and to use the Blend, Vertical Shift and Rotation sliders carefully.

• Colour Set: this is a key control. You use this drop-down menu to choose the Colour Set you want to use. These are grouped into Brown, Cool/Warm, Green/Brown, Moss and Violet/Pink categories, with four combinations in each.
• Opacity: you don’t have to use these bi-color effects at full strength. You can reduce the opacity so that they become much subtler, to the point where viewers may not even realise what you’ve done.
• Blend: this controls how smoothly the top color blends into the bottom one. You can use a high Blend value for a very gentle transition or a low value for a sharp transition, such as the horizon in my Tokyo skyline shot.
• Vertical shift: this slider moves the transition between the top and bottom colors vertically up and down the frame. I need it here because the horizon line is well above the center of the frame.
• Rotation: not all images have a perfectly horizontal boundary for the bi-color transition. Sometimes it’s useful to angle the filter effect with this slider.
• Opacity: this controls the overall strength of the bi-color effect. All Color Efex filters have this Opacity slider at the bottom, but this filter has an Opacity slider of its own at the top, so you could use either really.
• Shadows/Highlights: sometimes Nik filters can leave shadows looking crushed or highlights blown out. If that happens, these sliders can recover some of the lost shadow and highlight detail.

The Color Efex Bi-Color Filter can work fine on its own, but often I like to use it at slightly reduced opacity in combination with the Tonal Contrast Filter. This can give images a lot more depth and ‘punch’, an effect which goes well with the color shifts of the Bi-Color filter.

If you like this effect and you have the Nik Collection already, why not try it out? Alternatively, if you don’t have the Nik Collection, you can download a free trial which will give you plenty of time to check it out and see what else it can do – see the links below.

• DxO Nik Collection 8 review
• More Nik Collection news and tutorials
• Nik Collection free trial and DxO store