How To Read A Histogram

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What is a histogram? For photographers of all types, agreement your histogram is a crucial aspect of getting the best image quality from your photographic camera. If you don’t sympathise histograms, yous’re going to exist frustrated when your images plow out too bright or likewise nighttime, or only don’t seem to have a good level of dissimilarity and detail.

However, if you lot do understand a histogram, yous tin easily create beautiful images that take full advantage of your camera’s image sensor! You’ll exist able to expand your creative potential to include the most hard lighting conditions, without being afraid of pictures turning out unexpectedly bad.

In this commodity, we’ll explain how to “read” or understand a histogram, and how to utilise information technology both in the field and in Lightroom, so that y’all tin cull the correct exposure and produce the best image quality.

How To Read A Histogram

At first glance, a histogram may appear to be a very technical, un-artistic thing that you lot’d effort to avoid, particularly equally an creative, artistic person. Only, to be a competent, skilled digital photographer, information technology’s very important to at to the lowest degree have a basic understanding of what you’re looking at.

Don’t worry, information technology’southward quite simple! Once y’all realize what you’re looking at, it will go second-nature in no time.

how to read a histogram tone graph

Here is all that technical stuff, in a nutshell: A histogram is a graph of your image information. From left to right, information technology charts your image’s tones from black to white. A “fasten” or bump on the graph ways that a significant part of your image has tone in that range.

So, if at that place is a spike or bump on the histogram’due south left side, that means there are a lot of shadows. If there’south a bump on the right side, that ways in that location are a lot of highlights.

That’due south basically it! The best way to larn more and aggrandize on this basic understanding is to just look at a bunch of your ain images, and see if yous can recognize the various bumps of the histogram, and which parts of your image they correspond to.

how to read a histogram in lightroom
how to read a histogram RGB graph

Of course, if y’all’re set to dive in deeper, and sympathize more than about the technical aspects of histograms, you tin first looking at RGB histograms, and apply the same understanding of light and dark tones, to light and nighttime colors.

Why Is A Raw Histogram Unlike In Camera Versus In Lightroom?

Before we go any further, we must get through some bad news: The histogram you see on the back of your photographic camera is non going to be identical to the histogram you lot run into in Lightroom.

histogram raw vs jpg in camera
histogram raw vs jpg in lightroom

Why? This is because your camera is actually showing y’all a histogram based on a JPG image that is candy in-camera to stand for the raw file. Yeah, even if y’all shoot RAW and non RAW+JPG, you lot are still seeing a histogram from a JPG thumbnail of that raw file.

Lightroom, on the other manus, is showing you a histogram based on its own interpretation of that raw data. Information technology’due south all the same not directly a histogram of the raw data itself, just a representation of the processing you have practical to that raw data.

This is why it is very common for your images themselves to look very beautiful, vibrant, and contrasty on the back of the photographic camera, and yet appear noticeably more dull and night in Lightroom. Every raw prototype’southward histogram will reflect this divergence, also.

If this bothers you, y’all can attempt to minimize the difference past adjusting your in-camera processing to look more like to how the raw file volition appear in Lightroom. Look for your camera’southward image processing settings – they’ll be called “Moving picture Mode,” “Picture Control,” or “Creative Style.” Changing these settings won’t affect the actual raw image data, just the back-of-the-camera preview and its histogram.

Endeavor switching this setting from “Standard” to “Neutral/Natural,” for a slightly more un-processed await. In that location is likewise a “Contrast” slider within those fashion control settings, and you can turn that down as well for even flatter, more neutral looking images.

Merely remember that if you do shoot JPG, or if you shoot whatsoever video, these settings Will be practical to those files!

How To Use A Histogram To Get Ameliorate Photos

how to read a histogram to get a perfect exposure

Okay, so, at present that nosotros fully sympathize histograms, how do we use this data to get better photos? It’s really quite simple: Avoid the edges of your histogram, peculiarly with an important subject field! If the image data graph touches the edges of the histogram, that means you lot may first to lose image data.

how to read a histogram to get a perfect exposure 2
For this image, preserving both highlights and shadows is the goal, then, paying attending to both edges of the histogram is crucial

Of class, y’all want to correctly expose your bailiwick, whether it’s a light-toned or nighttime-toned subject field, or whether your ultimate goal is a loftier-key (vivid) or depression-key (night) image, you already know what looks adept to your middle. Merely employ your histogram as an aide in determining which highlights and/or shadows might be at adventure of being “clipped,” or lost.

It may be piece of cake for you to correctly expose most of your discipline, merely what about high-contrast scenes, with both highlights and shadows? That is where your histogram will come up in handy the most…

Preserving Highlights With A Histogram

Using your histogram, you lot tin “save” your highlights by making sure that the graph doesn’t slam into the Right edge of your histogram. If all the highlights in your image are important to you lot, and then you desire the histogram data to only barely approach or affect the right edge. If you see it hitting the edge, and particularly if you encounter it brainstorm to spike at that edge, and then your exposure is too vivid, and y’all need to darken it a piddling chip.

Preserving Shadows With A Histogram

The aforementioned technique applies to your shadows: You can relieve your shadows by choosing an exposure that doesn’t slam the histogram information against the LEFT edge. Especially if your subject is a mid-toned or darker subject field, you’ll probably want to chose an exposure that simply barely touches the left edge, and has no spike.

Using Your Histogram For Maximum Dynamic Range

Then, what if your scene has besides much contrast (dynamic range) and it bumps into both edges of the histogram? This is a situation that happens oftentimes in harsh or dramatic lite, and your histogram tin can be the nigh helpful.

ETTR: Expose To The Right

how to read a histogram ETTR vs ETTL

If y’all’ve heard about histograms at all before, then you’ve probably heard the phase, “expose to the right”, or ETTR. What does this hateful? It refers to your histogram, and making sure that your highlights are perfectly exposed at the right edge of the graph.

In other words, ETTR is saying:

“ignore the shadows, choose your exposure by paying attention to the single brightest highlight in the scene; put that highlight precisely at the right-hand border of the histogram, letting the rest of your epitome data fall wherever information technology may.”

This is a simple plenty concept, and while it won’t always guarantee y’all that your darkest shadows will exist saved, information technology will ensure that as much of your scene as possible is captured with the all-time overall image quality.

If your scene doesn’t have much contrast, and it easily fits within your histogram, can y’all just expose and so that the epitome data falls ANYWHERE on the histogram graph? Actually, ETTR is still a good thought in these situations, because the left (shadow) half of your histogram does non accept every bit good prototype quality every bit your right (highlight) one-half. In other words, if you lot severely under-expose your image, in-camera y’all volition meet a lot more than dissonance in all of the tones when you brighten the image in Lightroom. So, ETTR when you desire the to the lowest degree amount of dissonance in your image!

ETTL: Expose To The Left

how to read a histogram ETTL vs ETTR

Oppositely, if you want to ensure skilful image quality for the shadows in your photo, just you don’t care if you lose the brightest highlights of a scene, and so yous’ll need to “ETTL”. “Expose To The Left” means, of course, that the left-hand border of your histogram has get your main focus. Betrayal and then that the darkest shadow in your image is simply barely bumping into the left edge, and you take achieved ETTL.

A lot of people are confused by this, however, because often, to achieve ETTL, y’all have to “movement” your histogram data fifty-fifty more than towards the right, if there is a lot of contrast or dynamic range in the scene.

So, how do you tell ETTR and ETTL apart? Instead of thinking of it as “expose TO the…”, think of it as, “expose FOR the…” In other words, when you ETTR, you care about your highlights the most, and you betrayal to just barely preserve them. When you ETTL, you lot care most your shadows the well-nigh, and you lot expose to simply barely preserve them. Either way, you lot are disregarding the other. Meaning, if you lot ETTR, your shadows may still be lost, or if you ETTL, your highlights may very well be clipped.

Why You Should Use ETTL For Certain Situations

how to read a histogram ETTR vs ETTL highlight alert
(The Cerise represents the highlight alarm alarm, another great Lightroom tool. Discover there is no BLUE shadow warning!)

The big question is, why would you want to forsake your highlights, which aren’t recoverable? When you truly clip a highlight, it’due south gone. But, when you severely under-betrayal a shadow, sometimes it can be recovered. This is why most people apply ETTR, and non ETTL.

However, ETTL is a very useful technique in certain situations where your shadows and mid-tones are more important, and your brightest highlights are non. In portraiture, this actually happens a lot! Simply put, you shouldn’t base your entire exposure around a office of the image that is unimportant, and risk poor image quality (noisy details, un-saturated colors) on your important subject? Only use your histogram to correctly betrayal your subject, even if at that place are faces in shadow that require you to blow out a pocket-sized part the groundwork highlights.

how to read a histogram expose to the left
A perfect example of where y’all should probably pay attention to BOTH your highlight and shadow histogram edges

This will ensure that you always get images with good quality on the subjects themselves, and near of the fourth dimension, any clipped highlights will be minor.

Using Your Histogram In Lightroom

how to read a histogram in lightroom 2

Okay, so, y’all’ve captured your images, and you got a histogram that looks good for your type of subject. Is that information technology? Actually, histograms can be helpful in post-production, too!

In Lightroom, your histogram tin can guide you in the right management when editing your images. Information technology appears in the upper-right corner of both the Library Module and the Develop Module, but click on the Histogram tab to show/hide it.

how to read a histogram in lightroom 3

One of the best, almost powerful means to utilize your histogram is with the Tone Curve tab in the Develop Module. Lightroom overlays a histogram on your curve line, so you lot can adjust specific tones easily, and fifty-fifty employ the “dropper” tool to pivot-indicate multiple specific tones to adjust.


Now you lot know how to read and use your histogram. Whether your photography subjects are often landscapes and you religiously apply ETTR, or yous’re photographing portraits and activity and similar subjects where you tend to lean a fiddling more towards ETTL, the goal is to use your histogram to attain exactly the results you want, so procedure that raw image data in Lightroom to accomplish the tones yous want to see, besides.

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