F/Stop, Shutter Speed, ISO

A What Stop?

Remember the quiz you took at the beginning of the course? Were you a Professional Pete,

Wanna Be Wendi, Social Selfie Stacey, or No Clue Noah?

How much do you already know about f/stop, shutter speed, and iso? Take the short quiz below and let’s find out who you are now!

(Don’t worry – it’s not graded)

The lesson you are about to begin will teach you all you need to know about f/stop, shutter speed, and ISO.

Camera-Ready

Now it’s time to really dig in and learn what each of these terms means. Every camera is different so it will be up to you to locate and learn how to adjust these settings on the camera you’re using for the course. If there is a DSLR or manual exposure 35mm camera available to you I strongly encourage you to take advantage and use it! Even if it’s old, you’ll learn so much more this way.

If you choose to explore 35mm film and cameras contact your instructor immediately – some assignments will have to be adjusted and your instructor can recommend places for film processing.

Your camera manual is a great place to start learning! And of course, your instructor is always ready, willing, and able to assist you. When emailing your instructor with a camera question, be specific about what equipment you are using. Here are some examples:

Nikon D750 DSLR
Nikon D5100 DSLR
Canon EOX Digital Rebel Xti 10.1 Megapixel SLR
Samsung Galaxy S8 with Lightroom App
iPhone 8 with Camera FV-5 Lite App
com on Windows 10 OS

This is by no means an exhaustive list – if you can set the f/stop, shutter speed, and iso you can use it!

These three settings: f/stop or aperture, shutter speed, and iso are collectively referred to as the exposure triangle. The three settings work in tandem to determine the exposure of a photograph – what is light, what is dark, how dark is dark, how light is light, etc. In general, an in-camera meter will have one line underneath ‘0’ when the scene is correctly exposed. Consult your camera manual for specifics on your camera. Our goal for this microlesson is to “make the meter happy” and create correctly exposed photographs while manipulating the exposure triangle settings.

ISO

In Search Of??

Nope -that's not what ISO stands for here. ISO is one of three important settings on your camera that is used to take a well-exposed photo. These three settings are often called the Exposure Triangle. The other settings, in addition to ISO, are Aperture and Shutter Speed.

Let’s begin with ISO. This video gives us a great little introduction:

Your choice of ISO will have a direct impact on the rest of the exposure triangle, aka the aperture and shutter speeds available to you. Let’s do a quick comparison:

ISO 100

Less sensitive to light
Will require a slower shutter speed and/or wider aperture
Less grain = crisp, clear image (unless other mistakes are made)
Difficult to use indoor, may require additional lighting

ISO 3200

More sensitive to light
Allows for a wider range of shutter speeds and apertures
More grain = less detail in the image
Easier to use in difficult lighting, light indoor sports & concerts

Aspects affecting ISO

It’s important to consider which aspect of your photograph is most important

Is the subject moving? Do you need to stop motion?
Will you use a tripod or additional lighting?
Do you want a grainy photograph or one without noise?
Do you want a shallow depth of field or everything in sharp focus?

If there’s lots of light, the subject isn’t moving, and little grain is desired ISO 100 or 200 works well.

If the lighting is dim (indoor lighting is significantly dimmer than outdoor natural lighting), there is not tripod or additional lighting, and/or the subject is in motion ISO 800 or 1600 works well.

A faster shutter speed is needed to stop motion but with the shutter closing so quickly light reaches the sensor for a very short amount of time. A high ISO helps compensate by making the sensor more sensitive therefore a shorter exposure is needed.

Indoor sports, concerts, indoor receptions & parties, galleries, etc - These are all examples of when a higher ISO may be needed.

The following video explores ISO further.

The Speed of the Shutter

At the basic level, a shutter is a device to open and close an opening on the camera, allowing the film or sensor to be exposed to light. When choosing a shutter speed, the most important consideration is whether or not your subject is in motion.

Take a look at the image below:

Which pinwheel was photographed using the fastest shutter speed?

Which pinwheel photograph used the slowest shutter speed?

Measuring the Speed

Shutter speeds are measured in seconds. Adjustment knobs and internal displays often indicate whole second exposures with a different color or “ marks and show only the denominator of the fraction of a second that they are open form. For example, 30 means 1/30 of a second and 30” means 30 seconds. That’s a big difference!

You often don’t get to see all of the shutter speeds available to you at once so it can be confusing. Consider writing down all of your camera’s shutter speeds and creating a timeline for reference in your journal. If you do so, it will look something like this:

30” 15” 8” 4” 2” 1” 2 4 8 15 30 60 125 250 500 1000

In this example, each shutter speed is half the duration of the previous one. These are considered whole stops. Your camera may have additional shutter speeds in between these that represent half and third stops.

The video below goes into greater depth about aperture and f/stops.

Shutter speed is tied to aperture and iso in the exposure triangle. When choosing a shutter speed, the most important consideration is whether or not your subject is in motion. The faster the shutter speed the more motion will be frozen. However, this also means a higher ISO and/or wider aperture will be needed to create a good exposure. It’s also important to note that hand-holding a camera (working without a tripod) has its limitations with regard to shutter speed. It’s generally accepted that 1/30 is the slowest shutter speed possible without a tripod that will result in an image without a camera shake. But of course, it’s more complicated than that. Not everyone has as steady a hand. And longer lenses will show the camera shake at faster shutter speeds.

Take a look at the examples below:

Fast Shutter Speed Example

A fast shutter speed froze not only the horse but the dirt and mane crisply

Slow Shutter Speed Example

A slower shutter speed created a smooth, soft effect of the flowing water.

How Shutter Speed Works

Watch the video below to learn how shutter speed works.

Aperture

Aperture aka f/stop

A camera lens is composed of pieces of glass that are used to refract light and focus it as it enters the camera. Many lenses have an adjustable aperture, which refers to the size of the opening in the lens where light enters. The larger the opening, the more light enters, and the less time is required to create a good exposure.

Take a look at the scale below:

Depth of Field

Aperture size also affects "depth of field”. This is what creates the bokeh effect that is sought after for portraits and selectively focused images. F/2.8 is a wide or large aperture. This allows a lot of light to enter the camera at once. It also creates a shallow depth of field. This means that there is a small area in which objects will be in focus, while others will be rendered softly. A greater depth of field, such as with f/22, results in objects at a wide variety of distances from the camera in sharp focus.

Apply all that you’ve learned and create the following photographs. Your goal is to create a correctly exposed, well-composed photograph that also meets each specific requirement. Balance the exposure triangle settings – iso, aperture, and shutter speed.

You can use one of the applications below or your own camera!

Freeze something in motion
Create a portrait with a blurred background
Create a portrait of a person or object inside your home that is well lit

Applications you can try:

https://camerasim.com/camerasim-free-web-app/

Download the free app to your computer to your Apple device from the app store. There’s also a paid option

http://www.canonoutsideofauto.ca/play/

Completely free, but you can only take 3 photos

IMAGES CREATED BY GAVS