If you want to improve your photo quality, you need to master the histogram. The histogram is a graphical representation of the brightness and contrast of your image. It can help you avoid overexposure, underexposure, and loss of detail. In this article, you will learn how to use the histogram to adjust your exposure, contrast, and color balance in different situations.
A histogram is a chart that shows how many pixels in your image have a certain brightness level, from black (0) to white (255). The horizontal axis represents the brightness levels, and the vertical axis represents the number of pixels. A histogram can be displayed on your camera screen or in your editing software. A histogram can be either grayscale or color, depending on the mode you choose.
Some ways to get started with: -make sure you won't 'burn' your picture by reducing shades too much - histogram helps you to judge that (overdone contrast, overdone white balance) - every peak on the histogram shows how the shades are distributed on the picture, it's worth to study them - if there is no information on 0 up to certain number you can easily reduce the blacks until the information shows up as a tiny peak (if you overdo it the blacks will be 'burnt') - if there is no information on 255 or less - it means that the picture is too dark and it needs reducing the sadness and bringing some light... Hope it helps and good luck!
A histogram can tell you a lot about the exposure and contrast of your image. A well-exposed image should have a balanced distribution of pixels across the histogram, without any gaps or spikes. A gap on the left means that your image is underexposed, and some details are lost in the shadows. A gap on the right means that your image is overexposed, and some details are blown out in the highlights. A spike on either end means that your image has clipped pixels, which are pure black or white and cannot be recovered.
That “distribution of pixels” is not a one size fits all approach. You have a few data sets to consider… input (shooting) and output (editing/grading), and of course your intent: moody, dramatic, bright, etc. (emotional not technical terms) When shooting you should also know how your camera sensor and profile settings (standard/log etc) respond to being “pushed and pulled”… eg. When shooting in Sony S-log2/3 you typically want the histogram weighted more to the right than in standard profile. In other words, knowing your camera and reading histograms together will help you realize your intended vision.
The histogram should match the image/scene being photographed or at least the intended mood. If you're photographing a person with dark hair wearing black sunglasses and a black suit against a black background (think of the MIB Men In Black movie posters with Tommy Lee Jones and Will Smith), your histogram will be skewed to the left because of all the dark tones in the scene. That's perfectly fine because that's what the scene looks like. Consequently, if you're photographing a light-skinned person wearing a white dress against a white backdrop (say for Amazon), then your histogram would and should definitely be skewed to the right. Just make sure you don't have any darks or whites without data unless you're required to.
If you are shooting a scene that is all light or all dark tones, the graph will be weighted more heavily on one side or the other. On a shot with wide variation in bright and dark tones, yes, it should be balanced. Too much to one side indicates your photo could be under/overexposed. I find watching for spikes to be very helpful. These will indicate a part of your shot is has an area so bright or dark that you can’t correct it (missing pixels)Individual cameras/lenses/flashes can also under/overexpose, primarily when using auto programs. When you see a histogram that looks “off” consistently, you can compensate through adjustments to aperture, shutter or film speed. I find histograms especially useful when using flash or strobes.
One way to use a histogram to adjust exposure is to use the exposure compensation feature on your camera. Exposure compensation allows you to increase or decrease the brightness of your image by changing the shutter speed, aperture, or ISO. You can use the histogram to check if your exposure compensation is correct. For example, if your histogram is skewed to the left, you can increase the exposure compensation to make your image brighter. If your histogram is skewed to the right, you can decrease the exposure compensation to make your image darker.
Another way to use a histogram to adjust contrast is to use the curves or levels tool in your editing software. Curves and levels allow you to change the brightness and contrast of your image by manipulating the shape of the histogram. You can use the histogram to check if your curves or levels are correct. For example, if your histogram is too flat, you can increase the contrast by making an S-shaped curve. If your histogram is too steep, you can decrease the contrast by making a U-shaped curve.
A third way to use a histogram to adjust color balance is to use the color histogram mode on your camera or editing software. A color histogram shows the distribution of pixels for each color channel: red, green, and blue. You can use the color histogram to check if your color balance is correct. For example, if your color histogram shows that one channel is dominant or deficient, you can adjust the white balance or color temperature to correct it. If your color histogram shows that the channels are uneven, you can adjust the color saturation or hue to enhance it.
The best way to practice using a histogram is to experiment with different settings and scenes. You can try different exposure modes, lighting conditions, and filters, and see how they affect your histogram. You can also compare your histogram with your final image, and see if they match your vision and intention. The more you use the histogram, the more you will develop your eye and skill for photography.
Something to consider when utilizing a histogram is the dynamic range of the camera sensor and it’s relationship to the ISO. The higher the ISO setting, the more sensitive the camera sensor is, however increased sensitivity of the entire sensor doesn’t equate to equal sensitivity distribution across the entire histogram. Camera sensors lose the ability to retain highlights at the lowest iso settings. This is somewhat counterintuitive, since one would assume that the less sensitive a sensor is, the more detail it would retain in the bright areas of a scene. Knowing the relationship between camera ISO, dynamic range, and sensor noise will allow one to fully utilize the histogram to achieve the optimum desired performance.
Everything said in this article is technically true, as well as the contributions so far from other photographers and/or artists that use photography. But I want to emphasize the need to understand the technical fundamentals of photography. The fundamentals are paramount, but they are also just guidelines made to be broken. You need the understanding and the process of practice to know what to use when and, more importantly, what is your light source (natural or simulated, indoors or outdoors) and your intended outcome. What are the emotion(s)? So yes, it's very important to learn about the histogram. It's just one of the many variables contained within that special tool of creation known simply as a camera.