There’s a reason why high end cameras don’t have built-in flash, they suck. Shadows will form when using the flash with a moderate sized lens. The kit-lens and nifty-fifty are the only lenses that come to mind when trying to achieve shadow-less images from the flash. They are also severely underpowered compared to external strobes. Match that with a slow recycling time and you’ll surely have a hard and bad time capturing decent images. The built-in flash is not totally useless though. It can still be used sparingly for the occasional fill flash and low light captures.
Rading Speedlite by squinza
If you have not noticed how badly your built-in flash performs, read on to learn more about the benefits of external flash. If you already have an external flash, this might help you in realizing the full potential of your unit.
The largest difference between your built-in flash and an external flash is power output. For example, Canon 7D’s built-in flash has a Guide Number (GN) of 12 while an external flash like the Canon 580EXII has a GN of 58. So how does a GN work? Let’s use the 580EXII as the basis. Divide the GN with the distance of the subject, let’s assume 7 meters. Divide 58 by 7 and you’ll get 8.26. This is the f-stop you should use to get proper exposure. Of course, you won’t always be shooting at those distances. But it is good to know that you can do so if ever.
With a built in flash, shooting continuously will eventually overheat the bulb. It will automatically stop working so it won’t overheat and this means that you have to wait for a couple of minutes to shoot again. Unless you’re shooting at full power, an external flash will be able to keep up even at 12fps allowing you to get the perfect shot.
A swivel type head might seem to offer not much compared to a static built-in flash but this feature opens up a lot of possibilities. By bouncing the light and not aiming directly at the subject, the light source is enlarged. The most common use of this technique is by bouncing of the ceiling. The effect from this is softer light and smoother tones. The harsh direct lighting from a built in flash offers no contest compared to an external flash.
One of the best times to use your flash is when there is light. That may sound wrong but there is solid reasoning behind it. If you have plenty of harsh light, you can still take a properly exposed picture. However, unsightly shadows will definitely be visible on your subject. By using flash, the shadow areas are filled with light resulting in a more balance tone. A built in flash can do this but will be severely limited when the lighting is too strong (ambient light from the sun).
Brighton Zombie Walk 2010 by heatherbuckley
The term strobist has wildly scattered thanks to the internet. People from around the world share their setups and ideas which further concretizes the strobist community. A strobist is a photographer who uses an off-camera flash. Think of your external flash as a studio light. Light modifiers such as umbrellas, softboxes, gobos, etc. can also be attached to your external flash. This is less powerful compared to a dedicated studio flash, however it is also much more portable. By getting a dedicated flash, you also get a mini studio that you can use anywhere.
Chia by astragony
With so many advantages in using an external flash, why don’t most amateur photographers get it? The main reason is price. A mid-tier flash, Canon’s 430EXII for example, is worth around 270USD. This can get you a decent lens already. Most are not willing to invest in this type of equipment since they think a built-in flash would suffice. There are also external flash heads like the Canon 270EX, which is less expensive but also offer less power and flexibility. I personally won’t recommend getting this type of flash. You’re better off saving for a full featured flash. Another reason would be portability. Carrying around a DSLR with a lens can be tiring enough and adding an external flash would do no good.
If you think the advantages outweigh the price tag, then get one as soon as possible, it will definitely open up a variety of ways in approaching photography. If you can’t muster the price, I suggest that you borrow a flash from a friend. Experiment and use the various advantages found here. If you still don’t find yourself buying one, get yourself a decent lens first. However, sooner or later you’re going to need an external flash. An expensive lens can get you great shots but an external flash can give you more than that.