Histogram is an important component of image editing software. Most digital cameras nowadays display the histograms on the screen as you take the photos. This clearly suggests that they form an important part of images. They may seem a complex subject to those starting out, but in reality, they are easy to understand. Below is a discussion on the histogram that will help you grasp the basics about them and guide you to take better photographs and edit them like the best photo editing companies.
The histogram is nothing but a graphical representation of tonal values found in your image. Simply put, it gives you a count of tones in different brightness values. This covers values starting from black (0% brightness) to white (100% brightness). Dark tones are represented on the left, while the lighter tones are found towards the right end. The middle part represents the mid-tones which are intermediate between light and dark. The vertical axis of a histogram represents the amount of tones in one set of lightness value. Histogram depends on the exposure, tone-curve and other settings.
Shadow and Highlight Clipping
In case the edge of the histogram touches any edge, it shows that the details are lost. This is also called clipping. Further, highlight clipping occurs when the graph is touching the left edge of the histogram. Both these cases can be fixed by changing exposure settings according to the situation. For example, if there is sun in the image, it is obvious that highlight clipping will occur.
Many of the DSLR cameras have the facility of viewing live histogram. You will have to access the LCD screen of your camera for this. In case you notice any highlight or shadow clipping, you can make necessary changes. To save shadow detail, dial positive exposure compensation value. In order to save highlight detail, dial negative exposure compensation value and make the images darker.
Histograms also highlight the information regarding three primary colors namely, red, green and blue. The different diagrams mark different colors. A grey diagram shows you where the three channels come together. It might be a good option to use the histogram when you click a picture as it will give you a fair idea about the tones involved in the picture. This will help you in improving your product photo editing quality afterward.
Overall, histograms are used as a reliable indicator of the quality of the image you take. Make sure you proceed after understanding its basic concepts.