Color accuracy is essential for any photographer who wants to produce realistic and consistent images. However, different lighting conditions, camera settings, and editing software can affect how colors are captured and displayed. How can you easily check and correct photo color accuracy? Here are some tips and tools to help you.
A color checker is a device that contains a series of color patches that represent standard colors in various hues, saturations, and brightnesses. By placing a color checker in your scene and taking a photo of it, you can compare how the colors in your photo match the colors in the device. You can then use the color checker as a reference to adjust your white balance, exposure, and color correction settings in your editing software. Some color checkers also come with software that can automatically create custom profiles for your camera and lens based on the color checker data.
As much of my work eventually ends up on a 300 dots per inch CYMK press I still use a Pantone swatch book printed on a gloss , or flat surface paper, identified further by a number. Adobe publishing system software has evolved to the point where PhotoShop also uses a by the numbers calculation of a RGB screen display. As I started my magazine photographer / writer / InDesign career —following hand setting metal type, to cold press, to Postscript? and mixing chemicals for developing analog film in my own darkroom— I really credit an almost bashful Adobe systems rent to use software for pioneering the magic of "desktop publishing" circa 1980's.
This is a great way to check color accuracy on product photography. I almost always use this method when taking picture of products that need to be Pantone certified. This is just the first step to ensure you have exact colors on the out, whether printing or digital. This allows you to get a profile but there is a lot more to the equation and process.
Another factor that can affect your photo color accuracy is your monitor. Different monitors have different color profiles, brightness levels, and contrast ratios that can alter how your photos look on the screen. To ensure that your monitor displays the colors as accurately as possible, you need to calibrate it regularly. Calibration is the process of measuring and adjusting the color output of your monitor using a device called a colorimeter. A colorimeter is a sensor that attaches to your monitor and reads the colors displayed on the screen. It then compares them to a standard color space and generates a profile that corrects any deviations. You can use a colorimeter with software that guides you through the calibration process and saves the profile for your monitor.
This is a mandatory aspect when getting color accuracy. There is a whole article on calibrating monitors and creating a workflow to ensure color accuracy. Things like the brightness of your monitor, how long your monitor has been turn on, and the ambient light in your studio where you are editing can affect your monitor calibration. There are lots of options out there to calibrate, you need to find one that works for you. Also to note, there are new HDR monitors (like the apple one) where you will need to get a special calibrator tool.
A histogram is a graphical representation of the tonal distribution of your photo. It shows how many pixels are in each brightness level, from pure black to pure white. A histogram can help you check and correct your photo color accuracy by showing you if your photo is overexposed, underexposed, or has a color cast. A well-exposed photo should have a balanced histogram that covers the entire range of brightness levels, without clipping the shadows or highlights. A photo that is overexposed will have a histogram that is skewed to the right, with pixels that are clipped at the white end. A photo that is underexposed will have a histogram that is skewed to the left, with pixels that are clipped at the black end. A photo that has a color cast will have a histogram that is unevenly distributed among the red, green, and blue channels. You can use your histogram to adjust your exposure, contrast, and white balance settings in your camera or editing software.
A good practice is to move your histogram levels to fit within the graphs points on the chart, particularly when using levels. A good photo always has a good range from white to black, without over exposing the white and losing detail, or under exposing the darks, also losing detail.
A gray card is a simple but effective tool that can help you check and correct your photo color accuracy. A gray card is a card that has a neutral gray color that reflects 18% of the light that hits it. By placing a gray card in your scene and taking a photo of it, you can use it as a reference to set your white balance and exposure. You can either use your camera's custom white balance feature to set the white balance based on the gray card, or you can use the gray card as a target to adjust the white balance in your editing software. You can also use the gray card to set your exposure by using your camera's spot metering mode and aiming at the gray card. The gray card should be exposed at the middle of the exposure scale, neither too bright nor too dark.
Kodak 18% grey cards are for exposure only. They are not color accurate and vary. Macbeth and X-rite are best color accurate cards. They can help and be used if nothing else is available but even real color accurate cards will give a slight variance in neutral color across the card.
This does not always work. I generally feel a grey card is for video. Even better than a grey card is a white card or sheet of pure white paper. You can always shoot in raw and get the white balance close then adjust in photoshop.
A final way to check and correct your photo color accuracy is to compare your photos with other photos that have similar or desired colors. You can use photos from other photographers, magazines, websites, or your own portfolio as references. You can also use tools like Adobe Color or Coolors to generate color schemes and palettes based on your photos or other sources. By comparing your photos, you can see how your colors match or contrast with other colors, and how they affect the mood and message of your photo. You can then tweak your colors in your editing software to achieve the effect you want.
I am primarily a portrait photographer and want to ensure skin tone to 100% accurate. If I were to use a grey card and have the subject hold it up to his face for a test shot, it would almost always come out too warm/yellow. I start with a calibrated monitor and tether my images to Capture One. I have learned to start my wb at 4800 and a tint of 0. I can then make small adjustments to it till the skin tone is representative of the person standing in front of my continuous lights. I also use saturation to warm up skin tones, which makes it look more realistic. Getting the right skin tone takes practice and a developed eye for it but once you are able to see color, you have a super power that not many people have.