What is a Speedlight? What is the Purpose and Do I Need One?

This is a guide covering everything you need to know about speedlights.

What is a Speedlight?

The Speedlight is a small battery-powered flash that can work either when mounted or not.

Speedlights are starting to gain popularity among portrait and even studio professionals. They are small, very light, quick to set up and tear down, and lastly the price.

Originally, the term Speedlight was coined by Nikon in early 1960. They used it to name Nikon flashes that aren’t built into the camera. Then Canon showed up with their own term, Speedlite.

Nowadays, manufacturers will use one of the two terms to refer to their camera-mounted portable flashes.

The original camera-mounted flash units were manual and will always output the same amount of light. Shortly after, automatic flashes were released.

The automatic flashes use a sensor that is mounted in front of the flash to adjust the intensity of the flash.

Time goes on and all of a sudden TTL is now mainstream.

TTL is the abbreviation for Through the Lens, it means that your camera both monitors and controls your flash to give you the proper exposure.

Basically it’s an automatic version that lets the camera decide for you.

As usual, innovation naturally comes with a big price tag. Luckily, other companies have reverse engineered said Nikon and Canon Speedlights to make them more affordable.

In short, the Speedlight definition is a battery-powered portable flash that can be both mounted or not.

speedlight example

What is the Purpose of a Speedlight Flash?

The purpose of the Speedlight is to add additional lighting to conditions that are too dark for handheld photography.

You can only do so much changing your settings to allow shooting in dark conditions. Most of the time, you’ll need a slow shutter speed and that requires you to use a tripod.

Shooting at a slow shutter speed makes your image prone to motion blur. Since it’s almost impossible for most photographers to have their hands not shake for 5 seconds, they need a tripod. Oh, and maybe use a remote shutter release too as an extra measure.

Speedlight allows you to comfortably handhold your camera to achieve more balanced exposures in daylight.

You can also use it to add exposure when shooting at higher shutter speeds, allowing you to freeze fast-moving subjects.

Need more power than a built-in pop-up flash, but still want it to be flexible? Get a Speedlight.
Shooting handheld in low-light conditions but you’re at your ISO limit? Use a Speedlight.

Besides those, you can also adjust the power of your Speedlight. This helps you to effectively control the spread of light, either you want it to match your lens focal length or ensure the correct spread and light intensity.

It also provides a white card to bounce the flash and also includes a diffuser to create softer flattering light.

So to wrap it up, photographers will mainly use this affordable accessory to help their handheld photographs for exposure issues.

To further explore the purpose of speedlight flashes, check out this in-depth video by Patrick Berger:

7 Reasons why EVERY photographer needs a SPEEDLIGHT

How Does a Speedlight Work?

Placing your Speedlight into TTL mode and holding the camera button halfway down will trigger a pre-flash.

Your camera will pick this reading and input this info to the Speedlight to predict the approximate settings for a good exposure.

It will consider both the distance from the light source to your subject and the amount of light reflected off the subject.

TTL is best used in manual mode. Using it in any of the auto or semi-auto modes won’t get you anywhere.

Every setting is scrambling and adjusting each other to no end, just to give your the correct exposure. Adjust your settings for the ambient light and allow the flash to adjust accordingly.

If you choose to set the Speedlight into manual mode, you are made responsible to control the flash output which you dial in.

You can also control its output by placing the flash closer or further away from your subject. The closer it is to the subject, the more intense your light intensity is and vice versa.

Why Would Someone Choose Manual Flash Over TTL?

Well, considering your model will be in multiple poses in the same spot. It is beneficial to have a light source that is consistent in every shot and at the same distance from your light source.

To further explore how a speedlight works, check out this in-depth video by The Photographer Academy:

SPEEDLITE BASICS | Getting Started with Speedlites

What is the Difference between a Speedlight and Flash?

These two different systems made some photographers turn it into a debate of Speedlight vs. flash.

As you may know from my explanation above, I’ll try to explain about flash some more.

People will often call a flash a strobe too, they just create a brief flash of light.


Speedlight is essentially a TTL system that automatically measures your flash and allows better exposure to your subject.


On the other hand, the flash is essentially a brief secondary source of light to illuminate a dark scene. The Speedlight is surely more advanced in its capabilities, considering the other features that it provides for the photographer.

They have different yet similar usages.

To further explore the difference between speedlights and flash, check out this in-depth video by Adrian Lard:

SPEEDLIGHTS VS STUDIO STROBES | Which flash should I buy?

How Do I Choose a Speedlight?

Speedlights are taking the photography world by storm, leading to many photographers purchasing the product on a whim.

Some go for the most expensive speedlights, thinking that high quality is guaranteed by a high price. While some choose the cheapest options, without considering that manufacturers would lower the quality of the product to make it cheap.

For starters, it’s highly recommended to purchase a Speedlight produced by your DSLR’s manufacturer.

Afterward, you can choose products from a third party such as Metz that works with your DSLR. With the majority of flash features being controlled through the camera, you must take advantage of all the available features.

They also come in many ranges of powers/intensity. By looking at the guide number, you’ll figure out that the more expensive a product gets the more power it has.

Canon will usually have a range of four flashguns: 270EX, 320EX, 430EX, and lastly 600EX. The numbers, for example, “270” is a guide number of 27 meters that relates to your ISO at 100.

Using your basic ISO you can determine the guide number by multiplying subject distance to f-stop number. You can also determine your aperture by dividing your guide number by subject distance.

This is important because your light intensity is also determined by the distance of your Speedlight to the subject.

Also, consider features like head rotation if you are planning to soften or change the light on your subject. There are also “zoom” features that are available in high-end models.

It allows the Speedlight to detect changes in the focal length from 24mm to 105mm, automatically. This can help you concentrate light to cover long distances.

To further explore the subject of choosing a speedlights, check out this in-depth video by Jiggie Alejandrino:

8 Things to Consider BEFORE buying Strobes or Speedlights for FLASH Photography

Is TTL Flash Necessary?

Through the Lens Flash or TTL flash can receive information from the camera’s light meter. This happens by the multiple contacts at the camera’s hot-shoe.

Assisted by the metering information from the camera, the TTL flash will automatically set the necessary power output. In modern equipment, the metering becomes really accurate, leading you to easily take well-exposed images.

Each manufacturer has its own TTL flash, some of which are:

  • E-TTL : Evaluative TTL, by Canon
  • i-TTL : Intelligent TTL, by Nikon
  • P-TTL : Preflash TTL, by Pentax

It is considered that Nikon CLS has the most sophisticated, best technology, allowing the user to have more individual control from the camera.

The Nikon CLS allows multiple ratios between multiple groups, you aren’t given complete control though. On the other hand, Pentax doesn’t allow you to configure groups.

“But do I need it?” you say. Well no.

Many photographers will recommend you skip TTL and go straight into Manual mode. For photographers, control is simply everything they wished for. Going TTL will make most of your images less desirable, flat, and dulled by its flat background.

While TTL focuses on correctly exposing the subject, photographers still want their fair share of dramatic lighting with shadows and highlights in some areas.

The more control a photographer has on their image, the better it generally is.

Another problem with TTL is its margin of error. Every time the TTL Flash sends the signal back into the camera, there is a possibility that your camera settings would change.

Shadows, highlights, ambient lights, clouds, and everything else can change the metering. Compare that to when you go manual, you can just set the power and it just stays the same until the end of time.

To wrap this section up, let’s compare the pros and cons of a TTL Flash then compare it to a Manual flash.

TTL Flash Pros:

  • Flash power and zoom are set automatically when connected to the camera, either via hot shoe or infrared.
  • TTL can be used in any camera mode, Automatic, Aperture Priority, Shutter Priority, and scene modes.
  • You can also use it in manual mode.

TTL Flash Cons:

  • A TTL equipped with an off-camera flash will mostly be unreliable. Its measurements are affected by the sunlight and line of sight.
  • Pretty expensive, mostly five times of the manual flash
  • Hard to replicate results.

Manual Flash Pros:

  • Really affordable, you can get a quality build manual flash with only $100
  • Full control of settings
  • Acquire a faster understanding of your camera and how to use light effectively

Manual Flash Cons:

  • Only viable when shooting in Manual Mode
  • Both power and zoom must be set manually.

Oh and please note that TTL is still a great feature. Sometimes photographers can’t efficiently use manual mode at a location or venue with inconsistent lighting.

It may not be great, but it does get the job done.

There is also detail about HSS (High-Speed Sync), which you shouldn’t worry too much about when starting out. If you want HSS, go with a TTL.

Manual flash is limited by the camera’s shutter speed (usually around 1/200s to 1/250s). A TTL paired with a compatible camera will get you up to 1/8000s.

To further explore the subject of TTL vs manual, check out this in-depth video by ZY Productions:

What is TTL? (vs Manual flash)

Final Remarks

So, “what is a Speedlight?” It’s essentially a flash with fancy technology that measures and helps you get optimal exposure to the subject.

It mainly serves as a second source of light to fill in shadows for photographers shooting in poor lighting conditions. Half pressing the button will emit a pre-flash that measures all those little details for you.

While the TTL flash does get the job done by lighting your subject, you miss out on the creative opportunities and freedom to control your settings.

Both have limitations and their usage should be adjusted to your needs and ability. That’s all from me, good luck!


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