How To Use Color Historgrams on your DSLR
There are multiple histograms available for digital SLRs. Beyond providing information on the luminosity in your photo, they can also evaluate color data.
Step 1 - Histogram basics
Before you can start understanding color histograms, you need to be familiar with the basic concept of a normal histogram. From left to right, you have dark to light. The height at any given point indicates the amount of pixels in the picture that hold that dark/light value. In a standard histogram, the data is collected without any color taken into account. Basically, this graph gives you information as though the picture were desaturated. If you want to know what is going on with the colors in the frame, there is another option available to you.
Step 2 - Switch to color
Color can still be blown out, even if it is not white. This is why you may want to use a color histogram. More often than not, your camera will give you the option to view a red, green, or blue histogram. It may also show you all three at the same time. The graphs work in the same way as a regular histogram: the left side represents the darks, while the right side is the brights. However, now the histogram is only showing you the information for a specific color spectrum.
Step 3 - Exposure
As an example, imagine you are shooting in a forest as the sun shines brightly through a canopy of trees. You take a shot with some particularly radiant foliage. Your regular histogram desaturates the image, determines that all of the green leaves are shades of grey, and decides that they are properly exposed. However, look now at your green histogram. Now you may notice that you have a lot of peaking due to the sun blasting some of the leaves. The other histogram did not understand this properly because it does not pay attention to color. Fortunately, the truth is available to you.
Step 4 - White balance
Color histograms can also be useful in checking your white balance. In cases such as the one described in the previous step, you will have a lot more greens than any other color. When you look at all three colors together, the green levels will all be much higher than the reds and blues. However, in a normal scene where there is not a clearly dominant color, you can use the histogram with all the colors to judge whether your image is balanced. If there are many more pixels of any one color, then you know that something may be off. The whites and the blacks should be more uniform across all three spectra than anything in the middle, so keep your focus on those areas. When in doubt, hold up a white card or paper in front of the camera and make sure that the colors align.
Color histograms provide more detailed information than regular histograms. Though it may seem like a lot to process, the information can change the way you make decisions for your photographs.Popular Cameras for High Quality Photos: