Updated: Sep 19
In this article, I will introduce some of the most important photography terminology that every photographer should know, beginner or advanced. There are 50 terms at the moment, but this is an ongoing glossary, and we will be adding more words over time.
You may notice that the definitions below are more like “functional introductions” to each term rather than strict dictionary definitions. Personally, I consider that to be more useful. Sure, shutter speed is “the length of time which a camera’s shutter is open while taking a photograph” – but that doesn’t tell you much about why shutter speed matters and how to use it. Also note that there are a lot of topics here, and this is a long article – so if you want to jump to a specific term, I recommend using the list below:
Aperture is perhaps the single most important setting in all of photography.
Similar to the pupil in your eye, aperture is an opening in the camera lens that (generally) can change size. A large aperture lets in more light, while a small aperture does not let in as much.
For this reason, photographers like using large apertures in low light conditions. The largest aperture a lens offers is called its “maximum aperture,” while its smallest aperture is called the “minimum aperture.”
Aperture is like the “pupil” for your camera system.
At a given moment, the aperture you are using is designated by an “f-number” such as f/1.4, f/2, f/5.6, f/8, f/11, and so on.
One key – these numbers are fractions. So, an aperture of f/2 is larger than an aperture of f/8 (in the same way that 1/2 is larger than 1/8). This can be confusing at first and seem backwards, but it doesn’t take long to get the hang of it.
This illustration shows some of the most common aperture settings and when you may want to use each one.
A typical lens will have a maximum aperture of around f/2.8, and a minimum aperture of around f/22. However, it varies from lens to lens. Some (generally more expensive lenses) have a maximum aperture of f/1.4, f/1.2, or even larger. These are great in low light conditions because – like a large pupil – they let in a ton of light.
Other than capturing more or less light, the biggest impact of aperture is on depth of field (see “depth of field” below). Small apertures like f/11 and f/16 have more depth of field than large apertures like f/1.4 or f/2.8. If you’re a portrait photographer looking for buttery smooth backgrounds, you’re probably a big fan of 50mm or 85mm f/1.4 lenses for this reason. (Landscape photographers, like me, rarely need 85mm f/1.4 lenses, which is a great tactic for saving money.)
2. Back-Button Focus
By default, almost every camera autofocuses when you half-press the shutter button. However, sometimes you will want to take a photo without focusing beforehand. That’s where back-button focus comes in.
Rather than half-pressing the shutter button, back-button focus focuses via a button on the back of your camera instead. Then (after disabling autofocus from the shutter button), you have more freedom to focus when you want.
Practically every camera on the market lets you reassign autofocus to a button on the back of your camera, or it has a button that already does this by default (the AF-On button). Likewise, every advanced photographer I know who has switched to back-button focus has never looked back.
When you use large apertures, especially when you zoom in or get close to your subject, you’ll end up with a shallow focus effect. In other words, your subject will be sharp, while the background will be strongly out of focus.
The quality of this out-of-focus region – i.e., how it looks, how it’s rendered – is known as bokeh.
NIKON D7000 + 17-55mm f/2.8 @ 55mm, ISO 1000, 1/50, f/2.8
A lot of specialty portrait lenses (such as 85mm f/1.4 lenses and similar) are ranked more by their bokeh than their sharpness.
This term saw a surge in popularity recently when Apple released a commercial about bokeh. However, the quality of background blur is not very good on any phone’s “portrait mode” today, since it is all done with imprecise digital blurring effects.
You can read more about bokeh in our comprehensive article here.
Bracketing simply means taking a series of photos in a row with slight variations.
The most common type of bracketing is exposure bracketing, where the photographer uses different shutter speeds (see “shutter speed” below) to take a sequence of photos with different brightness levels.
Most cameras have a bracketing button or menu setting that automatically captures a series of bracketed exposures in a row. This can be useful, although it’s easy to forget you turned it on and continue bracketing photos for a while by accident.
Bracketing button on the Nikon D7000
Bracketing can also refer to focus rather than exposure. In this case – “focus bracketing” – you’re shooting images in sequence that are focused at different distances.
In theory, bracketing can refer to almost any variable in photography – even something like composition – but exposure and focusing are the most common contexts.
5. Camera Modes
Every advanced camera lets you select which settings (specifically exposure settings) you will change manually, and which the camera will change automatically. The setup you choose is known as your camera mode.
The five most popular camera modes are Automatic, Program, Shutter Priority, Aperture Priority, and Manual. You can switch from one to the other by using the “PASM” dial on most cameras.
Mode dial on an entry-level camera. Note the extra “scene” modes represented by various icons. These are not recommended; they are essentially just standard Auto-everything modes with a few algorithm changes. It’s better to learn how to set things yourself.
Advanced photographers generally stick to aperture priority or manual mode, because those are the only two camera modes which give you full control over aperture – again, arguably the most important camera setting of all.
6. Chromatic Aberration
A common image quality issue you’ll see in photography is chromatic aberration. “Chromatic,” of course, refers to color.
The two types of chromatic aberration you may see in your photos are called lateral and longitudinal chromatic aberration.
The first – lateral – is more commonly talked about. It typically shows up as red/green, yellow/blue, or cyan/magenta outlines around high-contrast subjects in the corner of an image.
Lateral chromatic aberration in the corner of an image (heavy crop)
The second – longitudinal – occurs when there are color fringes in front or behind your photo’s focus point. This occurs as purple fringing in front of your focus point and green fringing behind.
Longitudinal chromatic aberration (mild crop)
Both types can be corrected in post-processing software. However, lateral is easier to correct, with fewer residual effects in your photo.
Composition is the arrangement of elements in your photograph.
Some elements attract a lot of attention, especially those which are familiar (like people’s faces), bright, colorful, or high-contrast. The more attention an object attracts, the more “visual weight” it has.
So, composition is about arranging the visual weight in your photo – often to look pleasing, but not always. Composition should match your emotional goal for a photo.
In a given scene, different compositions will convey different emotions. That’s why it is so important to select yours with care.
This balanced, abstract composition carries a smooth and peaceful emotional message. NIKON D800E + 70-200mm f/4 @ 86mm, ISO 100, 1/10, f/16.0
8. Crop Factor
Based on the size of your camera sensor, you’re always shooting with a particular “crop factor” and you may not even know it.
Crop factor is calculated relative to the size of full-frame camera sensors. These sensors have a (no-difference) crop factor of 1×, because they’re the reference.
Smaller camera sensors literally act like “crops” of full-frame camera sensors. The specific amount of crop is the crop factor.
APS-C sensor cameras (one of the most common sensor sizes) have a 1.5× crop factor.
Micro Four Thirds cameras have a 2× crop factor.
Phones and compact cameras have much smaller sensors, and therefore greater crop factors. The iPhone has a crop factor of about 7× because of its small sensor.
If you put the same lens on two cameras with different crop factors, you will appear farther “zoomed in” with the greater crop factor.
For example, if you use a 300mm lens on the Nikon D850 (a full-frame camera, 1× crop factor), you get the expected 300mm field of view. But if you put the same lens on the Nikon D500 (an APS-C camera, 1.5× crop factor), you will have a much tighter view – equivalent to 450mm reference.
Crop factor also matters if you are trying to calculate equivalent aperture or ISO across different camera systems. See our article “Equivalence Also Includes Aperture and ISO” for more information.
9. Depth of Field
The portion of a photo that is (acceptably) in focus is known as your depth of field.
I like to think of depth of field as a window with thick glass that intersects the scene in front of you. Anything that touches the window is within your depth of field; anything farther away from the window is progressively farther and farther out of focus.
In a portrait photo, you may want to have a shallow depth of field, where only your subject’s face (or even just the eyes) will be in focus. In a landscape, you may prefer the opposite, where everything from the foreground to the horizon is within your depth of field.
Taken at a large aperture of f/2.8, which provides a shallow focus effect (thin depth of field)
The three ways to get a shallow depth of field are simple:
Use a larger aperture, like f/1.4 or f/2.8
Get closer to your subject
To get a deeper depth of field, you simply do the opposite. Use a smaller aperture like f/11, zoom out, and move back from your nearest subject.
At smaller and smaller apertures (f/16, f/22, even f/32 and f/45), you will start to see your photos get blurrier and blurrier. This blur is known as diffraction.
(To see the sharpness differences more clearly, click on the image. Pay particular attention to the pattern of colored dots on the woman’s face.)
Diffraction exists no matter what lens you use; it’s just a property of physics. For this reason, I generally try not to use apertures of f/22 or smaller.
That said, it’s not the end of the world if you do. Personally, I like shooting macro photography (see “macro” below), where I’m focused very close and my depth of field is extremely shallow. In those cases, I very often use f/22 out of simple necessity.
NIKON D7000 + 105mm f/2.8 @ 105mm, ISO 1250, 1/250, f/22.0
Distortion has a few meanings in photography, but the most common refers to an image quality issue (or occasionally feature) present to some degree in most lenses.
The three common types of lens distortion are barrel, pincushion, and wavy/mustache distortion. They look exactly like they sound:
These types of lens distortion bend straight lines in your photo, which is especially obvious with architectural photography. However, a few specialty lenses – fisheyes – advertise their extreme distortion as a feature rather than a bug.
Taken with the Nikon 10.5mm f/2.8 DX Fisheye Copyright © Nasim Mansurov
Lens distortion is generally easy to fix in post-processing with minimal side effects.
The other common type of distortion is perspective distortion. In this case, you’re getting very close to your subject (and generally zooming out a lot) to exaggerate its features.
Sometimes, extreme perspective distortion is nothing more than a gimmick. However, it can be quite helpful in emphasizing interesting foreground subjects, like lines on a sand dune.
12. DSLR Camera
DSLR stands for “digital single lens reflex” camera. It is one of the most popular types of advanced cameras, along with mirrorless cameras (see “mirrorless” below).
The two defining aspects of a DSLR compared to other cameras are its digital sensor and its reflex mirror. The reason for a mirror inside the camera is to direct light from the lens to an optical viewfinder. When you take a photo, the mirror swings out of the way so as not to block your camera sensor.
Today, the two biggest DSLR companies are Canon and Nikon.
Nikon D850 DSLR
13. EXIF Data
A digital photo has more information embedded in its file than you may realize. Alongside the image data itself, most cameras also embed information like your camera settings, date/time of capture, and copyright information. This additional information is known as EXIF data.
EXIF stands for “Exchangeable Image Format.” It is very useful to look at your EXIF data when post-processing photos so you can get better at using your camera settings. (Before deleting a blurry photo, look at its EXIF data to see if you can spot a problem with the camera settings you used.)
I recommend eliminating EXIF data from certain photos you post online due to privacy concerns, especially if the photos are tagged with GPS coordinates. Almost all post-processing software lets you delete EXIF data upon export.
An EXIF viewing program
There are several different meanings to the word “exposure” in photography. Most of them have to do with the brightness of your image, but not all. Here are the most common:
A substitute for photo (“I took a few exposures of this scene.”)
A substitute for shutter speed (“I’ll need a long exposure here.”)
Your shutter speed and aperture values (“My exposure for this shot is 1/10 second at f/8.”)
Your shutter speed, aperture, and ISO settings (“My exposure settings for this shot are 1/10 second, f/8, ISO 100.”)
The brightness of your photo (“This photo is too dark; it’s underexposed.”)
Precisely what a photographer means when they say “exposure” depends on the context. However, it is irreplaceably tied to the brightness of your photo and the amount of light you capture.
15. Exposure Compensation
This camera setting, exposure compensation, is a way to inform the camera to brighten or darken the photo compared to the camera settings you are currently using. (Specifically, compared to the metered exposure; see “metering” below.)
For example, perhaps you’re shooting a landscape, and part of your sky is “blown out” (too bright). To tell the camera to take a darker photo, you could input negative exposure compensation.
Note that exposure compensation does not darken the photo in all-manual mode, when you are in full control over aperture, shutter speed, and ISO (see “shutter speed” and “ISO” below). That’s because – aside from flash – those are the only three settings which can change the brightness of an image.
When you dial exposure compensation, the camera cannot magically take a darker photo without altering one of these variables. So if you are in aperture-priority mode (where the aperture is fixed), the camera will only ever adjust shutter speed or ISO when you use exposure compensation.
Personally, I use exposure compensation a lot, especially in combination with aperture priority mode. Specifically, when I take a landscape photo, I will select my aperture manually (because it’s so important to depth of field), then manually set my ISO to its lowest value. This leaves only one variable to adjust automatically – shutter speed. So, the camera adjusts shutter speed as the light changes, and I can nudge it either brighter or darker if the camera is consistently under/overexposing.
16. Exposure Triangle
The exposure triangle refers to the “big three” camera settings – aperture, shutter speed, and ISO (see “ISO” below). Aside from your flash, these are the only camera settings that alter the brightness of an image.
The Exposure Triangle
Note, however, that many photographers do not consider ISO to be part of exposure. While shutter speed and aperture physically change how much light you capture, ISO merely brightens the photo after the fact – not unlike raising brightness in post-processing. To keep the “triangle” name intact, a third variable – brightness of the scene – is sometimes used instead.