This is the 8th in a series of Silver Efex Pro 2 posts. Previously
- Overview & Interface
- Image Preview Options
- Global Brightness Adjustments
- Global Contrast Adjustments
- Global Structure Adjustments
- Global Adjustments, Wrap Up (Tonality Protection; Levels & Curves)
This post covers SEP 2 Selective Adjustments. In the SEP 2 default screen view shown below (click to enlarge), Selective Adjustments are found near the top of the right hand column labeled #5 (there are several other type of adjustments in this same column and they are covered in other posts).
The image below is section #5 (SEP 2 Adjustments) from the above interface screen shot – after expanding the Selective Adjustment section.
When using a editing program, adjustments such as saturation, contrast, sharpening, brightness, …. are applied throughout the entire image. They are global adjustments. When we want to make changes to just portions of an image, local or Selective Adjustments, things become much more difficult – unless you’re using a Nik Software product with their patented U Point technology.
(Note: historically, less than 10% of viewers click through on a link such as the one at the end of the previous paragraph. A word to the wise – that previous link is important to your understanding of what’s to follow. If you can’t take the time to view it – it’s not long – then you may be better off stopping right here and not waste any more of your time.)
Let’s start with a simple example image to illustrate some important things about Selective Adjustments and Control Points. Click any image throughout this post to enlarge it.
#1 – Selective Adjustments are implemented using something called a Control Point which is added to the image via SEP 2’s Selective Control panel. The next image shows the first step in the process. The top is our input to SEP 2 and the bottom is the preview of our adjustments.
The orange circle is the control point with all of its control sliders in the neutral/off position. There are a total of eight sliders which are from top to bottom –
- Control Point “boundary control” – shrinks/expands the CP’s area of influence; covered below
- Br – increase/decrease Brightness within the CP’s area of influence
- Co – increase/decrease Contrast within the CP’s area of influence
- St – increase/decrease Structure within….
- Amplify Whites within…. (increase only)
- Amplify Blackswithin…. (increase only)
- Fs – increase/decrease Fine Structure within….
- Sc – Selective Color within…. . (increase only)
Note that items 2-7 are selective versions of certain of the Global Adjustments covered in Global Adjustments, Wrap Up (Tonality Protection; Levels & Curves)
Here is another preview of our image. In this version, I’ve turned on the display of the CP’s “boundary”, a circle. The top slider allows the diameter of the circle to be changed.
A VERY IMPORTANT point about Nik U Point controls, regardless of which plug-in they appear in (they all work the same although the sliders will differ from app to app). The point is this –
- Image elements affected by changing the CP’s sliders depend solely on the color & tone of the image directly under the control point
- Let me repeat that – Image elements affected by changing the CP’s sliders depend solely on the color & tone of the image directly under the control point
- Or more precisely from the Nik Site (you did follow the link, right? Of course not.) The CP uses “…. values of hue, saturation, brightness (lightness), and image detail to create the complete and unique set of U Point Pixel Characteristics.”)
- English translation – even though an image element may appear within the CP’s boundary it WILL NOT be affected by the actions of the CP’s sliders UNLESS there is a color/tone match.
- I’m making a big deal of this because I read hundreds of requests (even from testers) asking Nik to change the circle to some other shape of the user’s choosing. NOT NECESSARY if you understand how CP’s work! Questions and misunderstandings abound!! To quote that popular answer to questions like this – RTFM.
- End of sermon – go in peace. Sorry, feeling extra grumpy today 😉
This simple image was chosen to “make perfectly clear” my points above related to the “circle” vs. what is actually changed by slider adjustments. I am going to illustrate using nothing but the selective color slider so as not to add any additional confusion. The next image shows what happens if I increase the selective color slider.
- Even though the CP’s boundary extends into the center (green) area we see a change only in the red (where the CP center is located)
- The entire red area isn’t changed because the circle limits the range of adjustment effects.
- Note that there is not a sharp cut off at the edge of the circle. I’ll discuss this and how to control that (if it produced undesirable effects) later
Your take away from this image (to repeat again) – Image elements affected by changing the CP’s sliders depend solely on the color & tone of the image directly under the control point (otherwise we’d see green in the center bar where the circle encroaches)
Note in the next image that the CP’s circle has been increased and, similarly, the area of its effect is likewise increased – but again only areas matching the CP’s location are changed (even though most of the green bar and part of the blue/purple is under the circle.
Moving right along – We can always see the area “selected” (this is about Selective Adjustments recall) by a control point (again, this applies to all Nik plug-ins). This is illustrated in the next image which shows the area “selected” by the control point in the above image.
The selection display is, in effect, a mask (to learn about masks and more about Nik U Point read here). In a mask, the selected area is white and the masked is black (analogy – covered with black masking tape so that you don’t paint over it). As expected, we see above that red (white in the mask) is selected and the remaining colors are masked out (black).
And – if we add a 2nd CP, similar to the 1st, in the blue area of the image what do think the resulting mask looks like? It looks like the next image. If this is a surprise there’s something that you failed to understand; try reading the section about masks in the previous link.
Here’s what the above image looks like if the masking option is turned off. (Actually the right bar would be blue if WordPress.com’s blog color management worked – but that’s another story.)
Finally, let’s add a 3rd control point – this time to the center (green) section. This time we won’t touch the selective color slider. Instead, we’ll adjust the rest of the sliders to get the brightest & most contrasty gray possible – something close to white. And voila, the center section is nearly white (compare with its color in the above image and, also, note that neither of the other two colors changed at all) –
OK – enough simple demonstrations of control points. Let’s move on to SEP 2 Selective Adjustment via CPs. Here is our example image – color original and SEP 2 B&W default preset. Lots of colors to play with as once again, for demo purposes, we’ll use just the selective color slider (the rest all work the same way but color is easiest to see when the underlying image is B&W). Note the control point (all sliders neutral for the moment).
Here’s another view of this image – this time using SEP 2’s option to display the area selected by the control (a mask). For demonstration purposes my ultimate intention is to limit the color changes to the left hand flower and no others. You can see from the mask that there is some “spill over” both within and outside of the CP’s boundary circle. We’ll deal with that in a moment.
Next is a preview of how the above actually looks (& you can see color in the other flowers where I don’t want it) –
One way to control unwanted “spill over” is to use neutral control points (this is what you automatically get when you click the Selective Adjustment’s Add Control Point button). A neutral CP says to the program – leave this (and all matching) areas alone; don’t change it unless I move a slider. This “undoes” the effect of the original CP’s selective color change.
A neat way to add these extra points is to go back to the mask and drop control points on top of white areas (if this doesn’t make sense read about masks one more time). The next image illustrates the result of this process with nine extra CP’s (which take about a second each to add; not a big deal). Compare to the image two above here.
The above, shown in the normal (non-mask) preview, results in the following. A mess of control points just to show what it took and, most importantly, no more color spill over (and if there were any, now you know how to deal with it).
in a cleaner view without the CP’s
Let’s bring in a little more color, for our flower of choice, as shown in this next image –
And maybe a bit of green foliage for background –
Bringing us to the end of this post on SEP 2 Selective Adjustments (plus a bonus on – hopefully – demystifying control points) –
Next in this series – SEP 2 Color Filters.
And, read this for a comprehensive post on Nik UPOINT control points.