Digital Photography 101: The Definitive Guide for 2018

digital photography

What are your goals for this year? 

  • Open a studio?
  • Build up a dependable client base?
  • Getting your work published?
  • Increase session revenue? 
  • Capture unforgettable photos of loved ones?

Here's a secret: 

No matter what your goals are, EVERYONE I've ever met who has reached and exceeded their goals with photography has gotten to where they are today by doing two things exceptionally well: 

First, they have a clear vision for what they want to accomplish. 

Second, they refine their craft over and over again by learning, practicing, and improving on fundamentals.

Sounds simple enough, right? 😀

It is, but there's a bit of a learning curve. 

Today I want to help shorten that curve by dishing out everything, and I mean EVERYTHING, that I've learned about getting started with a camera. 

This guide is for absolute beginners, seasoned professionals who could use a refresher, and everyone in between. In short if you plan on picking up a digital camera this year then this was written for you. 

Ready to dive in? 

Buckle up, we've got a lot of territory to cover! 


Part 1: The Exposure Triangle
Part 2: Shutter Speed
Part 3: Aperture

Part 4: ISO
Part 5: Exposure Compensation

The Exposure Triangle

First up: The Exposure Triangle. 

What is the exposure triangle you might ask? 

Cole Joseph puts it this way: 

"The exposure triangle is simply the relationship between your ISO, shutter speed and aperture. These three components work together to create an actual exposure or photograph. It is referred to as the exposure triangle because when you adjust one element, another element MUST change to capture the same exposure. When learning the photography basics and understanding the exposure triangle it is paramount to always remember this cause and effect relationship."

Here's a video from George Mason University that explains even further:

Now let's take a closer look at each side of the triangle. 

Shutter Speed

Shutter speed denotes the speed at which the shutter curtains open and close inside a camera.

It's expressed by a fraction of a second. A typical DSLR shutter is composed of two thin plates. Also known as shutter curtains, these move at a rapid speed to allow light to come into the camera and then resets after the exposure is done, ready for the next shot. 

Winter photo

An example of a fast shutter speed is 1/8000 sec (extremely fast). You can use a fast aperture if you're shooting outside on a bright sunlit day.

An example of a slow shutter speed is 1/6 of a second. A snail's pace shutter speed is perfect when you're shooting after sundown, with very little ambient light.

Controlling Shutter Speed

All cameras give you the option to control shutter speed, barring a few point & shoot systems from decades past.

The fastest shutter speed that is possible depends on the type of camera you have, the lens, it's maximum aperture, and the kind of ambient lighting condition you're shooting in.

If you're shooting in bright sunlight, with a 50mm f/1.8 lens you can easily hit 1/8000 of a second.

On the flipside however...

There is practically no lower limit for shutter speed, though most cameras do offer a built-in option of maximum 30 seconds of exposure time.

If you want an even longer shutter speed all you need is to switch to the 'Bulb Mode' and then hold the shutter button down for as long as you want to. Ideally, an external shutter trigger is preferred for shooting really long exposures.

This shutter speed cheat sheet from is super helpful for visualizing what various shutter speeds can be used for:

  Shutter Speed Chart

Types of Camera Shutters

Mechanical shutters that have physical curtains that open and close have been the most dominating for the better part of the last century and are still very relevant in 2018. There are two distinct types – a Focal Plane shutter and Leaf shutter.

Modern DSLRs and mirrorless systems however come with what is known as Electronic Shutters. Electronic Shutters are further divided into two basic types – Rolling Shutters and Total Shutters.

Rolling Shutters don’t expose the whole of the pixel array of a sensor in one go. They move information one row at a time.

On the other hand a Total Shutter will expose and move the information from the entire sensor in one go. They both have some advantages and disadvantages.

Here's how you can tell whether your camera has a Rolling Shutter or a Total Shutter:

Set you camera in your car window (or ask someone sitting at the passenger side to hold it up). As you drive down the street, ask your friend to make some images of the view through the passenger side of the car. If the buildings and the light posts appear perfect straight then your camera has a Total Shutter.

On the other hand, if the buildings and the light posts appear slanted, then your camera has a Rolling Shutter.

Advantages of Fast Shutter Speed

Football touchdown

A fast shutter speed is the perfect recipe for shooting high speed action.

If you're a bird photographer or someone who shoots any type of sports a fast shutter speed allows you to freeze movement. A shot of a Kingfisher hitting the water at 90 ˚ angle, or a strike in baseball, or a goal score in soccer are only possible with a fast shutter speed.

Advantages of Slow Shutter Speed

Slow shutter speed

On the other hand you need a sloooooow shutter speed to capture movement, create motion blur or allow sufficient time for your camera to collect more light in order to produce a balanced exposure.

Ideally, a slow shutter speed is required when you are shooting in a low light situation. You can combine a ND filter with a slow shutter speed to produce soft mist-like results for waterfalls and streams.

Use a Tripod When Using Slow Shutter Speed

Tripod with backdrop

A tripod is a MUST have because it allows you to stabilize the whole set-up and prevent any unintended blur.

Switch off the image stabilization on your lens / camera when shooting on a tripod. This helps ensure that the camera does not try to unnecessarily 'stabilize' the scene.


All lenses have an aperture.

It's one of the fundamental mechanical movements inside your lens. Without the aperture opening and closing you wouldn’t be able to capture light and therefore make an image. Nor would you have any manual controls over the exposure settings of your camera. 

Aperture denotes the small opening in your lens which allows light to travel through it and strike on the image sensor at the back of the camera.

This small hole on your lens can be controlled on a DSLR, medium format, large format, SLR and cine cameras.

The larger the opening the more light that is captured for a given shutter speed and vice versa. 

Aperture Number

Aperture is always expressed as a fraction – f/8, f/11, f/16 and so on.

F stands for the f-number, a ratio between the focal length of the lens and the diameter of the opening of the lens. It's not an absolute number though and a lot of other factors are also involved.

The actual mathematical expression of aperture is f divided by a number. Aperture can be expressed in whole stops or 2/3 stops or 1/3 stops. One stop is equivalent to doubling or halving of the amount of light.

Here's a typical full stop chart of aperture: 

Aperture Chart

Each stop on the right of the chart denotes halving the amount of light captured by the aperture before it.

Each stop on the left of the chart denotes doubling the amount of light that is captured by the lens.

Don't miss this:

The larger numbers denote smaller aperture.

The smaller numbers denote larger aperture.

Yes it's a bit strange, but that’s how it is! You will get used to this technique as you shoot more.

The way I've always remembered this is that the smaller fractions denote smaller aperture and therefore less amount of light. The larger fractions denote larger aperture and therefore a larger quantity of light.

Bokeh Effect

Bokeh photo

Larger apertures create the oh so sweet look of an out of focus background and foreground, commonly referred to as Bokeh. Try this out on shots where you want to draw more attention to your subject and less attention to the background.

Depth of Field and Aperture

Depth of field denotes the extent of the scene that is in sharp focus.

The smaller the aperture (smaller f-number) the more of the scene that is in focus and vice versa. This means that if you use f/2 you are likely to get a small amount of the scene in focus. But if you switch to f/8, or for that matter f/11, a much larger portion of the scene will be acceptably sharp.

Circle of Confusion

Focusing elements inside the lens barrel makes sure that the subject you are photographing is in line with the sensor. This is done by ensuring that the collimated lines originating from the subject converge precisely on the sensor.

When you use a big aperture (f/2, f1.8 and so on) light originating from only a small portion of the scene is converged on to the sensor. The rest of the light converges either at the back or the front of the sensor plane. Thus, a majority of the scene becomes blurred with the exception of the subject.

When you use a small aperture (f/8, f/11 and so on), light rays from only a small portion of the scene converge on the sensor, but light from a major chunk of the image will also be 'fairly' sharp as the converged rays will not be far off from the sensor plane. 

The bottom is line is that the major part of the image will look 'acceptably sharp'.

This acceptable area is known as the Circle of Confusion.

Relationship Between Aperture and Shutter Speed

Shutter speed and aperture have an inverse relationship.

They have to move in the opposite direction if you want to have a balanced exposure. A balanced exposure is one where you have detail in both the highlights and the shadow areas. The easiest way to do that is by selecting the appropriate metering mode and then making sure that the camera meter is on zero when you expose for the scene.


ISO refers to the sensitivity of the photographic sensor to light and is always expressed as a number such as 100, 200, 400, 800 and so on.

ISO stands for International Standards Organization. But that organization has a much wider role to play than just lend its name to something like sensor sensitivity. They create standards and norms for a whole lot of subjects and disciplines.

Sensor Sensitivity

Low Light Photography

The key difference between a digital sensor and using film is that sensitivity on the latter is fixed while sensitivity on the former is variable. When shooting you can dial in the right ISO number in a particular situation within a minimum and maximum number range.

The minimum number denotes the point of least sensitivity. On most cameras that would be 100. Some older cameras have the lowest ISO as 200.

The highest number denotes the maximum sensitivity point of your camera sensor. When you dial in the highest ISO number, your camera is able to produce a 'properly' exposed photograph even with the slightest amount of light.

Signal Amplification

ISO is all about signal amplification.

It may sound super technical, but it's quite simple. 

When light gets focused on the sensor it's converted into electrical signals and then passed on to the image processing engine. When you shoot at the base ISO, the lowest ISO your camera can shoot in, there's very little signal amplification.

But when the ambient light is low you are forced to use a higher ISO number.

At that point the light signals received by the camera are boosted using internal software. This compensates for the lack of light in the scene and produces a properly exposed photo even with low ambient light.

The Relationship Between Iso, Aperture, and Shutter Speed

Exposure Triangle

Remember the Exposure Triangle?

ISO shares an inverse relationship with the other two parameters of the triangle. 

Increasing the ISO means you are in effect increasing the amount of light captured (while not technically the exact quantity, you’re still achieving the same effect). Increasing ISO is just like opening up the aperture or using a slower shutter speed.

Negative Effects of Increasing the ISO

At this point you may be thinking that increasing ISO is a no brainer and a quick fix for capturing amazing shots.

Hold on friend, not so fast.

While it’s true that ISO will take care of your underexposed shots when you’re faced with the challenges of shooting in low light, there’s still a big issue involved with using too high of an ISO number.

That issue is noise.

ISO noise

Noise refers to the specs of white and black that sometimes appear on your images, especially those that have been shot in low light and particularly those where you have used a high ISO number.

These specs of white and sometimes black are nothing but the digital equivalent of ‘static'. It’s the same result that you get when you boost any signal. The higher the ISO number (and with it the lower the amount of ambient light) the higher the risk of getting these grains in your photos.

ISO Invariance

There are some cameras such as the Nikon D750, which are considered somewhat ISO invariant.

ISO invariance means the camera can shoot at a very low ISO number and then the resulting RAW file can be pushed in post-processing to reach the same exposure as you would have achieved if you had shot the image in the necessary high ISO number to begin with. No extra noise is added to the image in the process.

Exposure Compensation

Last but not least: exposure compensation.

Exposure compensation denotes dialing an exposure value that is more or less than what the camera meters for a given scene.

It's a creative shooting tool because it allows you to override what the camera thinks is the right exposure, allowing you to choose the exposure value for a scene manually.

Here's a photo without exposure compensation

No Exposure Compensation

And with exposure compensation

With Exposure Compensation

The Myth of Perfect Exposure

I hate to say it but there's no such thing as correct exposure

It all depends on what you (a.k.a. the photographer) want to capture and how you want to capture it.

If you feel that an image needs to to be overexposed, just so that you can capture the mood you want, go ahead and do it. Exposure compensation gives you that freedom.

On the other hand if you want to capture an underexposed image of a scene, you can do that too.

For more ideas on this I would recommend you to study some of the images captured by the brilliant Hong Kong based photographer Fan Ho. Over his career Fan played with the concept of over and under-exposure and created some of the most beautiful black and white photos that you will ever come across.

Alternative for Manual Mode

Check this out:

You can do EVERYTHING that exposure compensation does by using the manual mode.

You can choose to underexpose or overexpose depending on what you want in manual mode.

Manual mode is the ultimate in terms of creative freedom for a photographer. Exposure compensation is the closest thing to using manual mode without bravely turning the exposure mode dial to 'M'. 

Negative Exposure Compensation

Negative Exposure Compensation

Negative exposure compensation is the process of either dialing up the shutter speed, or using a smaller aperture, or doing both in an attempt to let in a lesser quantity of light compared to what the camera thinks would give a 'balanced' exposure.

When you tweak Exposure Compensation to the negative side of the meter you have the option to apply 0.3 stop or 0.67 or 1 full stop of negative exposure compensation.

This all depends on what you want to capture. Some cameras will allow you to dial in up to 5 stops of exposure compensation in one go.

Positive Exposure Compensation

Positive Exposure Compensation

Positive exposure compensation is the opposite of negative exposure compensation.

You apply a slower shutter speed or use a wider aperture with the intent to capture more light than what the camera's metering sets for a balanced exposure.

Exposure Compensation in Shutter Priority Mode

Exposure compensation can be used in Shutter Priority (TV), Aperture Priority (AV), and Program modes.

Exposure compensation will not work in Manual Mode for the explicit reason that you have the freedom to choose your own preferred aperture and shutter speed combination regardless of what the camera thinks is right.

In shutter priority mode exposure compensation will change the aperture value while shutter speed remains the same.

The exact process and combination of buttons and dials tend to vary from manufacturer to manufacturer and camera model to camera model so I won't delve too much into the exact steps.

You can find out more about the steps in the manual that came with your camera.

Pro tip: when it doubt, never be too proud to reach for the manual. 

Exposure Compensation in Aperture Priority Mode

In the Aperture Priority mode using exposure compensation tweaks the shutter speed of the camera.

This mode is ideal in settings in which you need to control the depth of field of your compositions.

An ideal situation would be when it is very bright and you have a lot of room to play around with the shutter speed. Another scenario is when you have a tripod set-up and shutter speed has become irrelevant.

Exposure Compensation in Program Mode

Exposure compensation in Program mode can increase (or decrease) either the aperture value or the shutter speed.

If the original metering of the scene is f/4 and 1/500 of a second, a positive exposure compensation of one full stop can result in either f/2.8 and 1/500 or f/4 and 1/250.

If you're a beginner exposure compensation makes it easier for you to make a proper exposure by tweaking one of the parameters and allowing the camera to take care of heavy lifting.

Outdoor portrait

So there we have it. 

There's a TON more to cover, but these fundamentals should get you on solid footing.

What's next?

Grab your camera and get busy! The best way to internalize information is to put it into practice immediately. Not tomorrow, not next month, not when you get your next client or when your cousin has a baby, but right now.

I'm not sure if practice makes perfect, but it sure does help. 

I hope that you find a world of satisfaction and fulfillment in making photographic art that is as unique as you are. 

Christine Mathis is a portrait and lifestyle photographer based out of Orange California where she lives with her husband Jeff and two kidos Ema and Sean. Her primary loves are coffee, a good weekend hike, and spending time capturing memories with family and friends.


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