Nikon Capture NX2 has only 5 blending modes while Adobe Photoshop has more than 20. Are Nikon Capture NX2 users missing out on many useful tools? Perhaps not. Adobe Photoshop is not only for digital photography, but also for a much wider applications. So some of the blending modes are of little use for photo editing or can be substituted with alternative blending modes. The purpose of this post is not to discuss the differences between Nikon Capture NX2 and Adobe Photoshop’s blending (blend) modes, but to illustrate what the blending modes do in Nikon Capture NX2.
To begin with, I quote the following from Nikon Capture NX2 manual as a reference so you don’t have go back and forth to find out exactly what I am talking about.
The blending mode determines how the image created by the current enhancement blends with the image prior to that enhancement. Using blending modes provides you with an advanced way of applying the current enhancement to your image. The different blending modes are:
- Normal – The Normal blending mode is the default blending mode for applying enhancements. When all channels for the enhancement are applied at 100%, the result is considered a normal enhancement.
- Lighten – The Lighten blending mode is achieved by applying the effects of the enhancement only if those elements are lighter than the corresponding area in the original image. That is, only areas that are brighter due to the enhancement will be applied to the image.
- Screen – The Screen blending mode is achieved by increasing the pixel values of the resulting image with the pixel values of original image. The resulting image is always brighter than the original image prior to the enhancement.
- Overlay – The Overlay blending mode is achieved by either adding or subtracting the pixel values of the resulting image from the original image. Capture NX 2 determines whether to add or subtract based on the value of the resulting image. Values above 128 make the final image brighter in the corresponding area; values below 128 make the final image darker in the corresponding area, while the value of 128 does not change the final image.
- Multiply – The Multiply blending mode is achieved by subtracting the pixel values of the resulting image from the pixel values of the original image. The resulting image is always darker than the original image prior to the enhancement.
- Darken – The Darken blending mode is achieved by applying the effects of the enhancement only if those elements are darker than the corresponding area in the original image. That is, only areas that are darker due to the enhancement will be applied to the image.
I use the following image to demonstrate the effects of different blending modes in Capture NX2.
I start with placing a Color Control Point (CCP) at the bottom of the purple flower followed by increasing of the brightness (by dragging “B” slider to the right) as shown in the following screen capture. As expected, the area around the CCP becomes lighter.
That’s what happened with the default Normal blending mode. If I change it to Lighten blending mode, what happens? Nothing. The reason is that Capture NX2 applies the adjustment only to where it is brighter due to the adjustment with the Lighten blending mode. Since we only made part of the image brighter there is no other area can be affected. If I add another CCP in the background and reduce the brightness, I see the following in Normal blending mode. The bottom left corner is darkened by the 2nd CCP.
when I switch to Lighten blending mode, the effect of the 2nd Color Control Point disappears as shown in the following image.
The Darken blending mode works exactly the opposite. In my example, switching to Darken blending mode makes the first CPP useless while the effect of the 2nd CCP is applied as shown in the following image.
The two other blending modes have opposite effects but the effects are applied globally to the entire image. The Screen blending mode makes the image brighter as shown in the following image.
The two control points still have their effects. You can examine this by toggling the check circle next to the control point in the Edit List. However the CCP that makes the image darker appears to have weaker effect. The opposite is true for the Multiply blending mode: the CCP that makes the image brighter now has weaker effect. The following shows the image with Multiply blending mode.
The effects are easy to understand but the way the manual describes what the software does in Screen and Multiply blending modes appear to be incomplete or incorrect. Screen blending mode is supposed to be “achieved by increasing the pixel values of the resulting image with the pixel values of original image”. Well, if we add two values greater than 128, the result is greater than 255. Does it mean anything above the mid tone will be blown out? No, it obviously isn’t despite some minor loss of highlights. So what the software does is more than what is described in the manual. The same goes for Multiply blending mode. If the software does exactly as described, I’d expect to see a completely black image if I added a Levels & Curves adjustment without actually changing the levels or curve but only changing the blend mode to Multiply. That doesn’t happen either.
As shown in this Wikipedia entry, the Screen blending mode does the following:
Result Color=255 - [((255 - Top Color)*(255 - Bottom Color))/255]
The Multiply blending mode does the following:
Result Color=(Top Color) * (Bottom Color) /255
That makes more sense.
I left the Overlay blending mode as the last one to discuss. What it does is making areas of the final image lighter or darker depends on the color values of the adjustment. Many perhaps have found the interesting Overlay blending mode that often seems to add some nice “pop” to a photo. There is nothing magical though. If you add a Levels and Curves adjustment without making any changes except changing the blending mode to Overlay, the result of the adjustment (the exact copy of the original image because no change was actually made) is blended to the same image. Basically, that is an overlay with the same image. In this case, darker part of the image becomes darker and lighter part becomes lighter, which essentially means increased contrast in the photos. You can get similar result by making a S-curve in the Levels and Curves tool but using the Normal blending mode. The following is the result of applying the aforementioned do-nothing-except-changing-blending-mode adjustment (The Color Control Points have been deleted).
If you don’t understand what the Capture NX2 manual says about how the Overlay blending mode works, you can try the following experiments.
- Open a photo in Capture NX2.
- Add a new adjustment step, select Colorize as the adjustment, select RGB=(128, 128, 128) as the color. With Normal blending mode, you see a blank layer of gray.
- Now change the blending mode to Overlay. You should see the original image.
- Now change the color in the Colorize adjustment to something like RGB=(50,50,50), the entire image will look darker. Adjustment color like RGB=(200,200,200) will make the entire image look lighter.
Do you remember the High Pass Sharpening method? Immediately after you add a High Pass adjustment, the image turns mostly gray (128,128,128). If you zoom all the way in, you will be able to see some details in the gray image. You can see the details only because they are either lighter or darker than 128 in any of the three color channels. High Pass filters out most image details, except those details that contain high spacial frequencies. If you change the blending mode to Overlay, most image areas will look just like the original, except for the details that pass through the High Pass filter. What you get is basically contrast enhancement at very fine scales, which makes the image appear sharper. To use High Pass as a sharpening tool, we typically also want to the opacity mixer set to Luminance & Chrominance mode with the Opacity (Chrominance Ch.) slider set to 0% to avoid undesired color shifts.
- Blend modes (Wikipedia)
- Photoshop’s Five Essential Blend Modes For Photo Editing (Photoshop Essentials)
Keywords: Blend Modes, Blending Modes, Nikon Capture NX 2, NX2