The ultimate guide to reading the histograms on your camera
A lot of people ask me about the histogram on the corner of your camera screen is. My standard response is: yes, they are more than a bunch of squiggly lines, and no, they are actually more useful than the LCD screen at the back of your camera.
Any serious photographer worth his money should be able to read histograms and use them to his advantage. That being said, it is not impossible to take beautiful pictures without reading histograms, as you probably had taken beautiful photos before you came across this article.
Histograms make pictures easier to edit and can help your photos look more professional. So, here is my guide to understanding histograms!
What are histograms, and why should I care?
Histograms are graphs (as you may have guessed), but when they appear on your camera screen, they become more than just that.
Histograms are the most accurate way to know the exposure of the photo you have taken or are about to take. And as a good photographer, you know that exposure can make or break a fantastic photograph.
Knowing the exact exposure levels allows you to adjust the brightness level, saturation level, and all that good stuff. So when you transfer your pictures into your computer to edit, it is almost effortless.
There is something so satisfying about taking a picture that hardly needs any editing. Doing that on a daily basis can save you hours of time and effort (besides being a great ego booster).
Now, let’s talk about that LCD screen or viewfinder that you rely so much on.
Remember what I had said earlier about accuracy?
Well, both those screens are affected by a lot more than just the lighting in the picture. Therefore, what you might think looks amazing on the LCD screen or viewfinder might not look as good when you see it later on your computer. Histograms are much more reliable in that matter.
How do I read a histogram?
Reading a histogram is surprisingly quite easy. It will be easier to understand how to read a histogram on your camera if you know how it works. Most cameras turn the photo or screen into its black-and-white version. The camera then sorts the amount of each color that is present in the photograph into a grey-scale spectrum. There are just three things you need to remember:
- The extreme left is for pure black, and the absolute right is pure white.
- If you guessed many shades of grey, you are absolutely right. This is the spectrum of grey tones between black and white extremes.
- This is for the number of pixels in the photo that fall into a particular tone of color. So if there is a tall pile of spikes at the right of the histogram, then the picture has more greyish-black tones (shadows), and if there is one at the left, there are more greyish-white tones (highlights).
And just like that, you can now read a histogram! It may take a little while for the process of learning to become so natural that it no longer needs any conscious effort. But as with everything right, it will come with practice.
What is the ideal histogram?
I would like to clarify that there is no “ideal” histogram in the same way there is no ideal photograph. Every photo is different, and so is every histogram.
Depending on the artistic intent of the photographer, the exposure can be adjusted. The “ideal” histogram is simply a rule of thumb to follow if you are a beginner or just want a realistic-looking photo with good exposure.
A photo is generally considered to have the right exposure if most of the spikes fall between the two extremes, in what I call the Midzone. It would also help if the spikes were evenly distributed. This simply follows on the common saying that anything in excess is bad. Therefore, when it comes to exposure, moderation is key. The trick is keeping the photograph neither underexposed nor overexposed.
What if most of the spikes on the graph are on the left?
This is called ‘shadow clipping.’ Shadow clipping is different from having a lot of shadows in your photograph. In shadow clipping, most of the spikes are squashed against the left side of the histogram, whereas shadows simply appear as a bunch of tall spikes more on the left of the center of the histogram.
If you remember what I said earlier, the extreme left means pure black. In the language of photography, this translates to no detail. As good photography is all about capturing all the little details, too many spikes squashed to the left would defeat the very purpose of the photograph. It just means that there is too much empty ‘blackness’ that has no detail and is merely taking up a lot of unnecessary space in the photograph.
What if most of the spikes on the graph are on the right?
This is called ‘highlight clipping’ and is an essential element of interpreting and understanding histograms. In highlight clipping, most of the spikes are squashed against the right side of the histogram. This is not to be confused with having a lot of highlights (peaks on the right of the center of the histogram) because highlight clipping results in loss of detail while simply having a lot of highlights does not.
Highlight clipping is considered to be more of a problem than shadow clipping. This is because, in real life, we often come across dark shadowy areas that we cannot make out much detail in.
On the other hand, we rarely see extremely bright areas unless maybe we are staring directly at the sun, which is both unlikely and harmful. Shadow clipping, thus, appears more natural and realistic than highlight clipping.
Having spikes squashed against either side of the histogram is not advisable unless you really know what you are doing. It is also challenging to fix this through the usual editing software. A glance at the histogram before you capture an image would only take a second and can help save a perfect photo idea from bad exposure.
What about the red, green and blue stuff?
Okay, I may have lied a bit. Reading a histogram is more than just understanding the black-grey-white spectrum. If you see red, blue, and green spikes, don’t be confused or dismiss them as meaningless. As your fifth-grade painting teacher must have told you, red, blue, and green are the primary colors from which all other colors are made of.
These colors are the ones that the camera detects and represents on the graph.
As these colors are neither black nor white, they fall into the Midzone. The rest of the area, which is usually grey, is simply the colors overlapping to make new colors. The higher the spikes of color on the histogram, the more of that color is present in a picture.
Now you may be asking yourself why exactly are you reading all this extra information. The answer to that question is simple– color saturation. If there is too much color on the histogram, especially on highlights extreme, then it is likely that the color is overexposed. You might have to dial the saturation of that color down a notch if you want to maintain the realism of your photograph.
High contrast versus low contrast
Histograms can not only help you identify the exposure levels of your photograph but also the amount of contrast in it. It is really simple to read the contrast in a histogram. There are only two types of contrast:
- High contrast shots have spikes mostly in the left or right sides of the histogram.
- Low contrast shots have spikes that fall roughly in the center of the histogram.
Of course, the level of contrast you want would depend on personal preference and artistic intent, but low contrast shots are usually the safest bet.
What do I do now that I know all this?
Use all your new-found knowledge to create awe-inspiring photography! By simply understanding histograms, you can adjust the exposure, saturation, and contrast of your picture in your camera before, during, or after taking a shot.
You will spend far less time furiously editing single photographs and trying to save what you thought would turn out to be a masterpiece. Just keep the histogram at the back of your mind while taking pictures fro amazing results.
However, remember that at the end of the day, no one became famous by following all the rules. Everything I have mentioned earlier is not a cut and dried rule. While it is good to keep these tips in mind, don’t get too caught up in them. Knowing how to handle a camera and read a histogram is one thing and having the artistic ability is another.
So whip out your camera and enjoy your photography journey!