Why you may Need a Flashgun/Speedlight for your DSLR
The plight of the pop up flash
A pop up flash is a useful inbuilt feature of a D-SLR camera, and can provide basic fill in light applications. However, there are some significant limitations that you’ll encounter when using a pop-up flash as your only option for an on-camera light source, especially if you’re seeking to greatly improve your pictures.
These inbuilt pop up flashes aren’t included in the designs of higher end D-SLRs.. Cameras such as the Canon 5D & 1D Series and the Nikon D600, D800s, D3s and D4 have a profound ability to capture details in low light situations -- greatly reducing the need for fill in flash/light. Entry level and prosumer cameras most times never have a full frame sensor like that of pro cameras, and may require more fill in light which can be accessed via the pop up flash.
Need for Artificial Lighting
But there is need for artificial lighting in a number of situations, regardless of what level camera you have. Even if your style is more documentary and photojournalistic, you will still come upon situations where you need a versatile fill in light or even a main light from your own emitted source.
Flashguns are more powerful than pop up flashes
Flashguns, otherwise called speedlights or small flash units, are simply much more powerful than pop up flashes.Typically, the intensity of a pop up flash may be effective up to about 3 feet, whereas flashguns may emit effective light from about 9 to 10 feet. This means that you don't have to stay close to your subject to provide illumination if you are using a flashgun. Actually, you can have your flashgun off camera and nearer to your subject that the actual camera is so as to maintain a consistent exposure for all your images.
Use the bounce light technique with flashguns
Bounce flash is a powerful technique that can be used to mimic the fall of natural light on a subject. It’s not easy to achieve this natural effect with a pop up flash, as you will need to utilize other accessories and material. And even if you can get some amount of bouncing light, the power will not carry much. With a flashgun, you have the option to tilt and shift the head to point the light in several directions -- even behind you! Bouncing light from off neutrally colored walls, ceilings and reflectors can provide you with greater creative options. Your photographs will end up appearing more natural, with better contrasts and less blown highlights.
Speedlights have automatic and manual modes of firing
Choose among modes such as the highly accurate automatic (TTL) mode and manual mode. Set the intensity of light incremental ⅓ stops in either positive or negative direction to suit your particular need with a greater range than that of a pop up flash.
Use a range of diffusers to soften light from flashgun
You can also easily add a wide range of diffusers to soften the light from a flashgun. Furthermore, you could even obtain a sync cable or wireless transmitter, so that you can use the flash unit off the camera and have even greater flexibility in where you direct light. This may be applied in macro photography and even wedding photography where it’s essential to have naturally looking photographs.
Omni-Bounce Diffuser for Speedlights
Set up a simple budget studio with flashguns
With at least two flashguns, you can literally set up a budget studio, even on location where you can use one flash as master, and the other as slave to get even more power over the final outcome of your images.
Lots of applications with speedlights to try
There are lots of tricks and tips that come along with the use of flashguns on your camera. Some compact cameras may have a hot shoe to place an on camera flash, and even some of the new mirrorless cameras have that option as well.
It’s great to use the pop up flash for basic fill in light, but when you wish to graduate and start doing some more creative lighting on a budget then it may be time to get yourself at least one flashgun or speedlight.
Flashguns aren’t without their limitations though and there are differences between brands and models that you need to take into consideration. After experimenting with the versatility and power of a flashgun, you may end up hardly ever using a pop up flash afterwards. They're more practical to achieve more natural looking photographs on a budget.