Color Processing: 10 Tips for Accurate Color Processing

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Color Processing

The ability to provide flawless color processing is one of the factors that differentiates beginners from professionals and dividing the latter into several categories. Generally speaking (very generally), the difference between “true” color correction starts to show up on a commercial and subtle artistic level. To read this article, it is highly advisable to be familiar with the White Balance Tool in Lightroom or Camera RAW at a sufficient level to perform basic balancing of the images.

When it comes to commercial photography, color processing is usually expected to meet certain criteria. For example, a brand has its own characteristic shade of “red”, which should be conveyed just like that. Accurate color grading will provide the desired result – usually demonstrated by side-by-side comparisons.

In the digital age, the issue of color processing is fraught with a huge problem: the photos displayed on the screen of a computer or smartphone look differently on different devices. I’ll show you some examples of how this affects color grading later. However, there are a number of manipulations that will get rid of these problems even at the stage of image preprocessing.

Photo without Color Processing
Photo Before Color Processing
Photo after Color Processing
Photo After Color Processing

Here you can see a comparison of the two photos. Everything is the same – except for the fact that I did the color correction on two different monitors. These are the differences that monitor calibration can bring.

10 Tips for Accurate Color Processing

Now, before we dive into the routine of color processing, it is very important to understand that color is as “true” or “accurate” as applicable to your photographs. This is your personal vision, and as long as you are not required to meet certain color standards, you decide how much to apply these ideas in practice, even if you want to put them first. I highly recommend at least playing around with the techniques mentioned to expand your Photoshop subtleties a bit.

Tips for Accurate Color Processing
Tips for Accurate Color Processing

1. Use Gray Cards

These things work wonders when shooting under controlled conditions, where you can influence the amount of light or at least the subject. Taking an initial photo with a gray card in the frame provides an area that will serve as a reference area for 18% gray. If you are not familiar with this concept, this point may not seem entirely clear to you. Just know that we are trying to set a reference that can be used when working with white balance in Photoshop / Lightroom / ACR. Larger gray maps / objects can also be used to calibrate the camera’s white balance.

I often see articles on color grading end after discussing white balance. To be honest, setting the correct white balance will not give you an absolutely “correct” picture. If there are mixed light sources in the frame (for example, fluorescent lamps or light bulbs with tungsten filament), some objects may take on a completely different color shade. Trying to fix all of this is pretty hard. However, gray cards are always a good first step towards achieving the desired result.

You can buy a 12×12″ gray card from Amazon.

2. Calibrate Your Monitor

I can’t even convey how important this is. Often there are several options to set the calibration to a specific standard, be it the printer model, corporate requirements, or any other “realistic” color setting – it all depends on the calibration device. This means that processed images will be displayed as close as possible to how you want others to see them.

While still young and inexperienced, I did a lot of photo shoots with my friends as models. Then I processed the pictures – it was so cool. But when I saw the pictures on my phone and another computer, their skin tone turned golden. And it was not just a faint glow, but a full-fledged golden hue. The background, which was supposed to look white or gray, also took on a yellow tint. I was so ashamed. Calibrating your monitor will avoid this failure.

In addition to the above, if you work on different devices, their calibration is vital, because you need to see the same color everywhere. Otherwise, you will make the photo look good on one screen, after two days open it on another computer and realize that everything has turned purple. I sometimes transfer a photo between several computers, as well as between my wife’s phone and mine, in order to visually determine the appearance of the photo on different devices.

The Datacolor Spyder5PRO is an excellent and relatively inexpensive calibration system.

3. Do Color Grading in The Morning

I’m not an early bird. I like to work with photographs late into the night: midnight or 1 pm is my time. However, one professor told me that our eyes are most active and distinguish color differences best in the morning. I hate to admit it, but she’s right. My best color grading is when I’m fresh and ready to start a new day. Late at night, your eyelids become heavy, your eyes lose focus or begin to clump together due to violent attempts to keep them open; night in this regard is not the best time for artistic work.

4. Print Your Works

It has become a bit of a mantra lately, and it’s especially true for color grading. The best way to make sure your photos are being displayed the right way in terms of color is to print them and view them in natural light. At the same time, to save time and money, you can print test strips: small pieces of a photo that cover the contrast range (try to pay more attention to pure black and white colors) and can be used to visually study color, brightness, contrast and other visible variables that you doubt.

Printing takes time. Especially when using large format printers. There are many small copy centers and private entrepreneurs who will take over the printing process; for example, there is a Latitude print center in Chicago that offers a variety of services, including large format printing. By resorting to such solutions, you save time and in some cases even be able to get help with color correction. However, be careful when asking someone to color correct your photos, as their vision of the final result may differ from yours.

5. Two Pairs of Eyes are Better Than One

Making friends with other photographers is a very good practice, especially for those whose interests are different from yours. They will be able to bring in some constructive criticism and offer advice that you would not have come across on your own. Among other things, it also provides an extra pair of eyes to help detect processing errors. After looking at a photograph for too long, sometimes even for days, the gaze gets used to it, and instead of the real picture, you begin to see what should be there. One of the best ways to get out of this state and “blur” your view is to take a short break, and during this time ask someone to look at the result and share their opinion.

I’m not a color grading expert. My way of dealing with unwanted color casts is to do my best to take control of every ray of light. Once I know what the light source is and what its temperature is, it becomes much easier to control the lighting. Unfortunately, this is not always possible. Projects, expectations and interests vary greatly and correlate in different ways with lighting conditions; I have several friends that I turn to if I need help with color processing.

6. Get Rid of Extraneous Tints with the Levels Channel

Let’s say you can’t use Lightroom or Adobe Camera Raw. How to get rid of unwanted shades from a photo? Perhaps one of the best (and fastest) ways is with a Levels adjustment layer. It allows you to control color, but all changes are made non-destructively. I strongly support this processing technique.

For this photo, I move the right slider (white triangle) to the left until it touches the first vertex of the histogram.

Accurate Color Processing
Accurate Color Processing

With a Levels adjustment layer added, set the white and black points by moving the sliders so that they are near the corresponding vertices of the histogram. This will instantly improve the appearance of the photo, as it brightens it up and removes some unwanted shades.

When the white and black points are set, open the drop-down menu of channels and repeat the same process for Red, Blue and Green. You will immediately notice significant color neutralization in the photo. These adjustments can be taken even further if needed, since you are essentially adjusting the white balance in a manner similar to that used in the corresponding ACR tool and Lightroom.

Improving White Balance
Improving White Balance

In the screenshots above, you can see the step by step progress in improving the white balance. However, after that, minor adjustments using Curves may still be required.

7. Use Curves to Hide Specific Bottlenecks

This is where things get a little more complicated. I am working on an article on color theory, which will be published in few days – subscribe to get notified and to get more in-depth knowledge. However, color theory is based on so-called “subtractive” colors. This means that when the colors are mixed, the resulting shade becomes darker.

Light has an additive circuit. By adding to one colored light another, you get a color that is closer to white. The most basic and understandable difference: the three basic subtractive colors create black, and the three basic additive colors create white. In addition, in an additive color scheme, the three primary colors are the result of a combination of the three primary subtractive colors – red, yellow and blue. ( Note – Most likely a mistake was made here, since the subtractive circuit contains magenta, not red.) The additive circuit consists of red, green and blue (examples of this are RGB monitors).

Each of the primary colors has its own complementary, hence the CMYK model is taken. C stands for Cyan, M stands for Magenta, Y stands for Yellow, and K stands for Key, but we won’t need it for now. RGB and CMY are arranged in that order because of their complementary pairs: red-cyan, green-magenta, blue-yellow. The more red in the picture, the less cyan, the more magenta, the less green, etc… These are the basics of color correction with curves.

Let’s say you have a photo that looks too blue (like the one above) even after adjusting the levels. You just add a Curves adjustment layer, select the Blue channel and drag the point down (you can also use the arrow key on your keyboard for this). This reduces the amount of blue in the image, which makes more yellow appear. Then you can continue to correct the image, that is, if after that it has acquired a too magenta hue, you can switch to the Green channel and tighten the curve a little higher, drowning out the magenta with green. It is important that all this is not done destructively – you can always go back and correct a specific part.

I omitted the curve too much on purpose to demonstrate how the image became more yellow. Note that the image has also become darker.

8. Machine Specific Areas

The light behaves completely insane. It jumps all over the place; physics claims that the angle of incidence is equal to the angle of reflection, but at the same time it bends, dances and penetrates all the cracks, including those in which you do not want to see it. Each time light is reflected from a surface to illuminate another area, it changes its hue depending on from the wavelength of the absorbed wave (I know this sounds very confusing, bear with it a little more), as a result of which a smaller and less noticeable shade is discarded.

However, you already know how to deal with problem areas – using curves. Aside from being non-destructive, adjustment layers boast masks so you can apply them locally. So, if the reflected light or unwanted light is giving a small area a tint, you can correct it with curves and then mask the adjustment layer so that it doesn’t affect the entire photo.

It’s very easy to get confused with this approach. This is no different from the work of artists who spend hours touching up the details of a painting or trying to create such detail that they have to work on it for weeks. Again, you can work on your shots any amount of time until you’re happy with how your shot looks on paper or on a screen.

9. Use Curves – Advanced

When using curves, you adjust the relative brightness of the color channels. The lower the curve, the lower the channel luminosity (in fact, the process is a little more complicated, but this is the result that worries us in this context). For this reason, if you need to significantly reduce the strength of a particular channel (s), you will get a darker shot.

Use Curves
Use Curves

To remedy the situation, use opposite complementary colors. As an example, here’s the photo above, which was too blue: instead of muffling the blue channel, letting the yellow show up (which will make the image much darker than expected), try boosting the red and green channels by about the same amount and get a similar result, and the overall brightness of the image will increase.

This technique is more difficult because it requires a strong conceptual understanding of the additive color model, or at least diligence to understand in practice which channels to use and when.

The opposite situation is when you need to enhance the main color (for example, if the image is very purple), when you increase the green channel value, there is a risk of getting a photo that is too bright. In such a situation, it is better to reduce the red and blue channels by the same value and get the same effect, but with lower image brightness.

This is by far my favorite part of the color correction process, but it takes quite a long time even though I went to art school. Only practice leads to perfection, especially when it comes to working with color. Don’t be afraid to be wrong.

The colors are similar, but the second image is much brighter. Again, I deliberately overdid the curves to clearly demonstrate the effect.

10. Work in a Dimly Lit Room

This tip is most effective if you have calibrated your monitor. Usually, when processing, you want to increase the brightness on the contrary. You want to see everything you’re working on. However, we work with light and when the luminosity (brightness) of the picture changes, even if it is just a representation on the screen, the interpretation of specific shades changes.

Some professional photographers even buy special monitor covers, like this one for the Mac. They prevent stray light from hitting the screen and affect the perception of the picture – it’s like turning off a ceiling light and / or working in a low-light room.

In some situations, color accuracy is completely subjective. Don’t reject subjectivity in your art and don’t be afraid to break rules or fall short of expectations. However, knowing how to work correctly with color correction no matter the situation will have a positive effect on your understanding of light when shooting and creative processing. Knowing the “rules” will teach you how to break them better.

You may also like to read: Color in Photography and Its Rules: What is Color in Photography?

Finally, I also want to say – if you are going to print your photographs, keep in mind that the lighting in which you look at the picture affects its perception. If you know what the lighting will be for a photo or can influence external factors, look at it in similar conditions to make sure it looks good. There are also dedicated color grading lightboxes that can be used to see if a photo looks right in white light – no matter the final destination.

The most important thing is to have fun. Push the boundaries, experiment with Curves and your masking skills, see how far you can go. Create insane and exaggerated effects just to see how each color channel affects the processed images. Don’t drag curves in one direction, see what happens if you make an S-shaped one. Invert it! Don’t limit yourself! In the end, ask for constructive criticism and prepare yourself to spend a lot of time honing even simple color processing techniques.

10 Tips for Accurate Color Processing
10 Tips for Accurate Color Processing