Bouncing flash from a wall or ceiling can make all the difference!
A way around using direct flash (except when using built in flash) is to bounce the flash from a ceiling or wall. This will diffuse the light and spread it more evenly over your subject and can make all the difference. I am all for bounced flash personally and it is a technique well worth learning!
It is important to note that when using bounced flash, you are effectively doubling the distance that the light has to travel. That means by the time the light reaches your subject; it is too weak to light them correctly, it can confuse the metering system.
To get around this, you simply double the power output to compensate by using the FEC (flash exposure compensation) on the camera OR flash unit.
This works if the subject is fairly close. The further away they are, the more output you will need to apply...+2, +3 etc.
It is also worth remembering that it is your aperture that determines the flash’s brightness recorded on your sensor or film. It's the shutter speed that determines how much ambient light is recorded. This is one of the best things you can learn for really effective indoor photography.
Think about it
Imagine you are in a dark room with just a candle burning in the back ground.
Now, your flash synch speed is around 250th/sec maximum (meaning you cannot use a faster shutter speed than that but you can use slower) and the flash fires at around 5-10,000th/sec so you can really shoot using a shutter speed of anywhere between 250th/sec, 60th/sec, 1 second, 10 seconds, a minute or an hour…it won’t make any difference to the flash output whatsoever.
The shot will look practically the same because the flash is firing at supersonic speed regardless of what you do. Have you ever seen a super slow “flash”?
All you can do is control how that flash is recorded by altering the power of the flash and how much is let into your camera (how long for).
So, as you decrease the shutter speed, the candle light will appear brighter and brighter the slower you go. A fast shutter speed will not record it at all. So, in manual on your camera with no flash at the moment, slow the shutter speed down until the candle is recorded nicely and how you want it and now you have the ambient light covered.
Now, add the speedlight and bounce it from the ceiling using say f8 for your starting aperture setting. If the rest of the shot, other than the candle, is underexposed, gradually open the aperture until the rest of the room suits the mood and looks well lit and voila, you have the flashlight and ambient light well mixed and exposed!
Watch the video above that illustrates this in more detail.
If you noticed in that video, the image improved dramatically when using an aperture of F8 as opposed to F1.4 in the first shot. This is why it is important to take control of the camera and get it to do what YOU want not the other way around!