All You Need To Know About External Flashes

In one of my previous article, I talked about cheap speedlights (external flash, flash) and a reliable dealer to purchase from. In this article, I am going to talk more about external flash or speedlight as most people would want to call it. We are going to dig deep into speedlights, plus we are going to learn about the flash modes each flash has to offer. Armed with this knowledge I am about to share, I doubt if you would ever have issues with speedlights again. All you need to know about flashes is right here so read on carefully.

What is a flash?

A speedlight is basically a device used in photography for producing a flash of artificial light at a color temperature of about 5500k to help light up a scene. A flash (speedlight) is used majorly to illuminate a dark scene. A speedlight is also used for capturing quickly moving objects or for modifying the quality of light. Your camera’s on board flash is a lousy piece of equipment which produces harsh light and leave ugly shadows everywhere. On board flashes leave no room for light modification or diffusion, so you are better off with an external flash.

What do I need to know about external flashes?

There are a million stuffs you need to know about external flashes especially if you plan on buying one soon. Here is all you need to know about flashes:

Hotshoe mount: this is a little device on cameras where an external flash is mounted. This interface allows for communication between a flash and a camera. It also lets the camera fire the external flash whenever you hit the shutter button. Sony cameras operate a complicated range of hotshoe mount which includes the propriety hotshoe mount inherited from Konica Minolta after buying the company in 2006. These kind of hotshoe can be found in sony cameras like a33, alpha 200, a55, a700, a900 etc. Lucky, sony introduced a stardard shoe mount (ISO 518 standard) in 2012 which they called multi interface shoe(MIS). This shoe mount can be found in cameras like a3000, a6000, a6300, nex 6, a77, a7s, a7r a7rM2 etc. If you own a sony camera and you want to purchase a flash gun, kindly use the comment box and I will personally guide you. Other cameras use standard hotshoe so you don’t need to worry that much about compatibility issues.

Guide Number(GN): the guide number of a flash is used to determine the maximum power of light beam a flash can generate in a fraction of a second. A speedlight’s guide number is determined at ISO 100, with low guide number (GN) indicating a weak or less power than one with a high GN. For example, the Yongnou YN560 III has a guide number of 58m (ISO 100). This is pretty powerful and should be just the right amount of flash power you will need. You wanna always make sure whichever flash you want to purchase has a high Guide Number(GN).

Tilt/swivel head:

some flash heads can be rotated about a fixed point to some certain degrees; this is known as swiveling. Some flashes also allow movement of flash head at some angle. Basically, this is all about moving the flash head up and down on a fixed point; this is known as tilting. This is a must have feature in every speedlight as it allows photographers to point the flash at an angle and bounce the light in order to create soft light. Stay away from any flash that lacks this feature.

HSS: this stands for high speed sync and it is a feature that allows you to use a faster shutter speed than your camera’s native sync. Normally, all cameras have a native sync which simply means the fastest shutter speed you can use when you are using the camera’s pop up flash. This feature allows you to use a flash at faster shutter speed. This is a create feature which lets photographers capture more aesthetically pleasing images with flash.

Flash modification: direct light from speedlights are strong, creates ugly shadows, harsh and unflattering. You can always find a work around by using a flash soft box, umbrella and stand (when shooting off camera) or bouncing the light from the flash on a large surface like the ceiling, walls, etc. in order to create soft light and eliminate that annoying shadow.

Off camera flash: you can mount your flash on a flash stand and trigger it using a wide range of methods. Like I said, direct light from hotshoe mounted flash is not the best. Using a flash off cameras creates more interesting, dramatic and professional looking images because you can set the light to illuminate your subject from an angle. You can also make the light even softer by adding a flash modifier like an umbrella.

Flash modes

We are not done yet, there are some other stuffs you need to know about external flashes:

TTL mode: some speedlights are TTL compactible with some certain cameras. TTL (through the lens)mode allows the camera to analyze a particular scene and set the flash power accordingly. This is just like auto mode on a flash, the camera sets the flash power and zoom based on your camera’s setting, focal length of the lens and the scene in general. Nikon refers to this mode as i-TTL, Sony P-TTL and canon E-TTL. Always watch out for this particular feature whenever you go flash shopping.

Manual mode: this is the opposite of TTL mode. You set the flash power, zoom and every other thing yourself. Your camera does no evaluation; all it does is just to fire the flash whenever you hit the shutter release button. Manual flash only come with one connection pin unlike TTL flash. Some flashes in the market are manual only.

Slave mode (S1 mode): this is a special mode that lets you trigger off camera flash with your camera’s pop up flash (optical trigger). This mode in particular fires a speedlight whenever it sees a flash of light from your pop up flash or another speelight. One disadvantage of this mode is the ability of the flash to go off prematurely as a result of pre-flash.

Slave mode (S2 mode): this mode works exactly like the S1 mode. The only difference is that the speedight ignores pre-flash and fires whenever the main flash goes off. Slave modes only work in manual mode only.

Wireless mode: another way you can trigger a flash off camera is by doing it wirelessly with the help of a radio transmitter. This simply involves using a flash remote on your camera’s hot shoe to fire a flash off camera.

Zooming: this is a feature which physically moves an element within the flash head to change and control how the light spreads. Setting the flash zoom to wide angle allows the flash light spread wider whereas setting the flash zoom to telephoto concentrates the flash in a tighter pattern.


That is all you need to know about external flashes for now. I believe this will be a valuable resource for everyone out there hoping to take a leap into flash photography. If you have any question, contribution or whatsoever, kindly use the comment box below.