This is part of a series I am working on to show the more advanced, professional-level qualities of Sagelight.
The curves, at first, may seem like they aren’t necessarily for everyone. But, they can be very useful even if they might seem intimidating, as a lot of traditional image-editing concepts and functions tend do that. I know that it took me a long time to really understand what was going on with curves.
Perhaps that’s why I spent so much time designing and writing the Curves function in Sagelight, as there are many innovations in the Sagelight curves to make them much easier to use. You can watch this video to get an idea of this, and you can also see the other videos I have posted regarding the curves.
The fact that I posted a number of videos on the Curves shows a couple things. For one, how useful they can be in enhancing your image. Two, it also shows that they do take a little getting used to.
Background on the Curves in Sagelight
Old-School Curves vs. New Technology in Curves
Curves are a traditional part of image-editing. As I wrote Sagelight, I realized that, though curves are very, very useful in the editing process today, they have also become old-school technology, and have been relegated to simple and less-than-elegant toning.
As I researched the curves issue, I realized I wanted to put them in. I had considered them too old-school to be useful in Sagelight. Then I ran across a plug-in called Smart Curves. I used to distribute this with Sagelight (it’s a free plug-in). After using the Smart Curves plugin for a while, I realized that curves had a definite place in Sagelight, but only if they were incredibly enhanced to make use of modern approaches in image-editing and to fit into the overall editing process.
The Power Curves is just such an example. One of the reasons why the Smart Curves Plugin convinced me of the usefulness of curves in editing today is because it supported the LCH mode. This is a powerful editing mode in the curves that can do amazing things with your image. I know I discuss this in various videos, and intend to do a video just on using curves in the LCH mode, as well as the HSL and other modes.
In traditional Sagelight style, I don’t like providing a lot of singleton functions, because there tend to be natural things you want to do. For example, I provide a set of saturation and other controls with a number of functions, such as the vignetting, Tone Blender, Bokeh, etc;, because that’s a natural thing you want to do.
The curves were no different. One of the things that you want to do immediately (and while) using curves is to adjust how the color is changing.
The Power Curves in Sagelight has a Chroma channel on the RGB (using Sagelight-developed RGB saturation, which is a very deep saturation, as well as the basis for Sagelight Vibrance) and other modes where normally you wouldn’t see it.
The Chroma Channel, added as a separate curve channel, by itself, as well as in conjunction with the other modes and color spaces in the Power Curves, transforms the old-school curves into something that much more useful to today’s image editing.
General Curves Interface
One of the other places I identified problems with using curves with today’s image editing, and where they had become old-school, in my opinion, we the interface. I really didn’t like having to select one curve after another by moving away from what I was doing, pressing a channel button – or wose, select the channel from a drop-down menu – to get to a different channel. This caused me to lose focus and made the entire curves process more cumbersome.
A lot of time and design went into creating a curves interface where you can very rapidly switch back-and-forth between curves channels, simply by grabbing the displaying non-active channel and moving it – most of the work was in making sure the Curves Window understood what you wanted to do, since these curves can be very close to each other.
This also made the process that much easier, as it allows you to change curves without losing your creative focus – you can just play and experiment, which is the basis for how Sagelight tends to work. The ability to be unintentional also helps you when you have a plan, as it makes the controls work that much more fluidly.
Fine Curve Adjustments
Another place where the curves technology was extended vs. traditional curves levels was in the fine-tuning. This is particularly useful in the Light Blender, but is useful overall.
You can use the keyboard arrows and the mousewheel to finely adjust the curves points. Since a lot of curves work is about subtlety, you can adjust the points with a high-degree of accuracy without the traditional method where you had to grab the point again, lose your focus, and replace the point without having the context of what it looked like before.
You can also hold the control-key down to make an even finer adjustment.
Curves in the Quick Edit Mode and Pro Quick Edit Mode
The Curves in the Quick Edit and Pro Quick Edit Modes provide a powerful set of curves functionality. While the Power Curves provide a wider array and more powerful set of standalone curves functions, the curves in the Quick Edit Mode and Pro Quick Edit mode have many embedded functions that are designed to work directly with the other controls of the Quick Edit Mode.
There are also a number of functions within the Curves in the Quick Edit/Pro Quick Edit modes designed specifically for these modes that are not in the Power Curves.
General Help and Video Sections
The video above is split into different sections. You can click on the links below to go directly to that section. You can also go to the general help section on “Curves in the Quick Edit and Pro Quick Edit Modes” for a recap of this blog entry (it’s basically a copy of the help section), later on when the different sections may be more relevant.
Basic Controls. This shows how to easily use the basic controls of the Curves Window, which are the same throughout sagelight. After that, things get different, as dicussed in the following sections.
Color Toning. This section shows how to use the Curves in the Quick Edit Mode for color toning your image, and how the Curves algorithms help integrate into the Quick Edit mode by keeping the luminance the same throughout the toning.
Correcting Color Casts. This section shows how to use the embedded curves functions to correct color casts in the same way you would with the “Remove Color Cast” function, but with more control since you can change the resulting curves yourself.
Auto Levels and Auto Color. This shows how to perform the same Auto Balance functions used in the Sagelight functions, but with more control over the result.
Pro Quick Edit Mode and C*I*E LAB and HSL Color Spaces Color. This shows how the Pro Quick Edit mode curves can be used in the C*I*E LAB and HSL modes. Similar to the Power Curves, but you can use the other controls in the Pro Quick Edit mode together with the curves in these color spaces.
he Curves in the Quick Edit/Pro Quick Edit modes have the same basic interface as the curves eslewhere in Sagelight (see the Quick Reference section below), which contains an advanced, easy-to-use architecture that allows for much easier curves than tradtional methods, while also providing a large amount of power.
The traditional problem with curves is that they can be difficult to use, which can interrupt the creative flow. Sagelight curves offer easy background curve selection, fine-tuning using the keyboard and mouse wheel, as well as the ability to easily switch to different color spaces.
In the Quick Edit and Pro Quick Edit modes, Luminance-keeping functions allow the color curves to be used as color toning curves, which is a powerful tool, as this allows you to adjust the results of the other controls used, rather than completely changing the light and tonal changes already made. You can also switch this off to use the curves as normal curves.
Remove Color Cast and Auto Balance Functions in the Curves Window
In some ways curves can be limiting. For example, the RGB Adjust tools in the Quick Edit Mode/Pro Quick Edit Mode offer essentially a minimum of 10 simultaneous curves windows open at the same time. The Curves Window, by comparison, provides one curve for each RGB channel + the RGB channels together.
However, curves give you much more direct control, allowing you to manipulate curves in a way not possible with the RGB adjust controls. You can use the Options Window to perform the same functions as the Remove Color Cast and Auto Balance functions. The results are then displayed as curve points which you can directly manipulate. This can provide more flexibility and power to adjust the results, where the Remove Color Cast and Auto Balance functions, while powerful, provide you with a more limited set of results.
Interactive Quick Reference
Click on the image above to go to the Interactive Quick Reference. When you move the mouse over the round tabs, it will display information for that control.