They are superficial lights that we can use when taking pictures. This will help in dark situation or to help with normal lights. Speed Lights can be called: strobe flashs or flash guns too.
Definition of Speedlight from Wikipedia:
Speedlight is the brand name used by Nikon Corporation for their photographic flash units, used since the company’s introduction of strobe flashes in the 1960s. Nikon’s standalone Speedlights (those not built into the company’s cameras) have the SB- prefix as part of their model designation. Current Speedlights and other Nikon accessories make up part of Nikon’s Creative Lighting System, which includes the Advanced Wireless Lighting, that enables various Nikon cameras to control multiple Nikon flash units in up to three separate controlled groups by sending encoded pre-flash signals to slave units.
Nikon competitors Canon and Ricoh use the similar name Speedlite for their flashes. Both names indicate that strobe flashes produce much shorter and more intense bursts of light than earlier photographic lighting systems, such as flashbulbs, or continuous lamps used in some studio situations.
Flash on top of camera:
When working with flash it is wiser to set the camera on ‘Aperture priority’.
One of the program settings of the back of the flash is called: TTL (Through The Lens) where the camera talks to the flash automatically and leads the flash to use the right speed.
As any automatic function, it might not be perfect. It could be too dark or too light.
Note: On a Nikon camera, when Flash is on the camera can not go under: 1/60sec
Here is a source to understand Focal Plane Flash (FP Flash)
Hi-speed (FP) Flash Synchronization
Focal plane (FP) flash seems to be a quite new technology but surprisingly the concept is already known for some decades. It allows faster sync. speeds than just e.g. 1/200s. With very fast shutter speeds the opening between 1st and 2nd curtain is never as large as the whole film so a single flash burst would lead to a partially unexposed film. As a solution you have to have a constant flash light for the whole exposure time. Unfortunately modern flash units have a peak emission characteristic so a single flash is not usable for this purpose. Today most manufacturers use a series of high frequent flash bursts (say 50 kHz) with reduced single light emission to simulate a (theoretically) long single constant flash burst.
Obviously there’s also a drawback with this kind of flash exposure. The following picture illustrates a single flash burst (in FP mode). As you can see most of the light is blocked by the 1st and 2nd curtain so the effective guide number is reduced dependent on the shutter speed. The faster the shutter speed the smaller is naturally the opening between the two curtains and the less flash light reaches the film. GNs may vary from flash unit to flash unit and between the manufacturers. The practical possibilities are a bit restricted at really fast shutter speeds.
Using the flash direction:
Straight flash is not flattering at all, but as you move it up , it gets better and better.
If you get an orange and grainy result, this means that there was a mixture of 2 different lights.
If the flash is tilted back a bit so that when facing people the flash doesn’t blow up on their face, then this will be a flattering shot and will look as a ‘butterfly lighting’ shot.
This is a great way to take pictures at weddings when everybody needs to look their best.
The flap on top of flash can be added too, this will give a wide angle feel to the picture too.
Another technique is that when the ceiling is high and dark: the advice is to add power, and on the opposite situation where there is too much light and it is bright in the room, it is wiser to take the power down on the flash.
Another setting on the flash is: ‘M’ (Manual) where obviously the photographer would have to do everything manually, after setting up the camera, the flash has to be set up too.
In case you are shooting a sports event or somewhere where something or somebody is moving quite fast, the flash has to be put on ‘repeat mode’.
In this case, there will be lots of flashes firing so for example you can get a runner on different shots and won’t have to wait for the flash to recharge.
Flash off camera:
In this case the built-in flash gun acts or should act as a controller. Although if this does not work, then use:
- A flash gun to work as a controller
- Or a flash trigger as a controller. These are to be put on top of camera, just like when using triggers with studio flash (brand ex: yongnuo is quite good)
Once this is decided, both camera and flash have to be set as ‘Manual’.
There are many available such as honeycomb grid or comb … The Speedlight can be used as studio flash gun.
Not enough power:
In case of needing a bit more power the best way is to get a ‘Pocket Wizard’.
To understand see explanation below from a forum I found on the internet.
It is basically a way of transmitting and receiving information so all the flash guns can work all at once.
Transmitter = send
Receiver = receive
Transceiver = send & receive
Here is a better explanation from online forum:
Pocket Wizards send signals to each other or to Pocket Wizard enabled devices, which Canon and Nikon flashes are not. The mini TT is a transmitter. It only sends a signal and is for the camera to send the information from the camera to a device than can pick that signal up, translate it and use it. The other devices are transceivers which can transmit and receive signals so they can be used on the camera or one the flash.
You need at least one mini TT transmitter for the camera and a transceiver for each flash or a transceiver for the camera and once for each flash. So no matter what, you need one Pocket Wizard device on the camera to send the signal and one Pocket Wizard device on each flash that you want to trigger via Pocket Wizard.
Some devices like sekonic light meters and Profot and Dynalite packs have PW receivers built in.