RGB, CMYH … it sounds like a bunch of alphabet soup. They are, in fact, used to describe color in the world of digital photography. It is important for photographers to understand these two conditions because they have an effect on the color of your photo, both on screen and in print.
A quick explanation is: RGB for the web and CMYK for printing. It’s a little more complicated than that, so its color spectrums take a closer look.
What is RGB?
RGB stands for Red, Green and Blue and refers to the three primary colors that can always be mixed together to create different colors.
When your DSLR- at a picture take your camera to compose your shot using an RGB spectrum. Computer monitors also work in RGB , so what users see on their LCD screen will be easier to see on their monitors.
RGB is known as a yoga color spectrum, it relies on adding different amounts of three colors to make different colors.
- In the RGB alphabet, there are 256 levels of brightness that create 16,777,216 (256x256x256) color possibilities.
- We can create black by setting each RGB color to a setting of “0”.
- Similarly, the “255” setting for each color is white
Therefore, RGB is the industry default for DSLRs and computer monitors, it allows us to see true-to-line colors on our screens.
What is CMYK?
However, if we want to print our images using a proper color spectrum, we need to convert to CMYK. It stands for Cyan, Magenta, Yellow and Black.
CMYK is used as a subtractive color spectrum, as cyan, magenta, and yellow pigment filters. This means that they subtract different amounts of white, light to red, green and blue to create different colors.
Therefore, an image displayed on a computer monitor cannot match a print unless the RGB spectrum is converted to CMYK. Although many printers now automatically convert from RGB to CMY, the process is still not perfect. As RGB is not a dedicated black channel, black can often appear very rich.
Work with printers
Technology has evolved rapidly in recent years, and you don’t always need to convert from RGB to CMYK if you want to print a single photo. However, there are some examples where this is necessary.
Print at home
Most desktop printers in the home and office are CMYH. Printing technology in both software applications and printers now does a very nice job of automatically converting RGB colors into CMYK.
For the most part, the in- house printer doesn’t have to worry about conversions. However, if you find that your blacks are not quite accurate, you can print a conversion and a test to see if it helps.
Working with commercial printers
You can work with two types of commercial printers and someone asks you to convert a picture to CMY.
In most cases you don’t have to convert today. This is especially true when using photo printing labs. Their software and technicians will usually handle the most challenges in producing the most potential photographic print colors. They want to please the customer and they know that not everyone has a complete idea of technology.
If you accept items such as postcards, brochures, etc. on a dedicated graphics printer for your work, they can ask for the image in CMYK. It’s because of the format that they’ve always worked with. CMYK, also known as four-color printing, dates back to the days of color printing and processing, even before the fiction of digital technology.
Convert from RGB to CMYK
If you want to convert an image from CMYK to RGB for printer, it is very easy and almost every image editing software has this option.
In Photoshop, it’s as easy as navigating: Image> Mode> CMYK Color
Once you send the files to your printer, work with them and print a test (a proof) to confirm what color you expect. Again, they want the customer to be happy and you will be happy to walk through the process.