Continuing this series on Histograms, we assume that you have already seen earlier 2 Parts of this series, because that's important to set right context around this.
Before we move further, just have a look at first image showing three different types of histograms. These are not from a camera but from Adobe Photoshop Lightroom, but that doesn't matter because this will look same for an unprcessed photograph in a Camera.
Let's focus on first Histogram and try to understand what exactly this histogram is telling us. On Horizontal plane of this histogram, we have tonal range. The left most point shows the darkest tone and right-most part tell us about brightest tone. Vertical bar of the histogram signifies number of pixels of a particular tone.
Forget about the colors you see as of now. So simply we can say that first histogram is for a photograph having dark tones in it and lot of area is near to darkest possible. These colors like Grey, Red, Green, Blue, Yellow, Cyan and Magenta have also a great significance but that will come in last. It will be great if you can guess about next two histograms before moving ahead.
Let's see some histograms with corresponding photographs.
Hope you will be able to relate to this photograph. Let's see the histogram and try to map the information with photograph on left. See the long vertical line on extreme left of the histogram, which means darkest pixels in this photogrph, Blacks. I hope you can see pure black regions in this photograph. The other tones of various colors are also aligned towards left whether its red, green or any bother color. There are some bright pixels but very few.
Try to interpret this Histogram ??
This one as well...
This is one of the special example of a histogram with grey colored indicators only. Here we shall not discuss about the colors and their relation with histogram. So leaving here with a thought around relation of Colors with Histogram and then see factors which we should take care while shooting photographs.