Using an on-camera flash often feels difficult to master, whether it’s with a built-in flash or one mounted in the hot shoe on top of the camera. The problem is simply the size of the light source itself (very small if we don’t use some devices to make it bigger such as reflectors or umbrellas) as well as the direction of the light, close to and following the axis of the lens.
Nevertheless there are easy ways to use an on-camera flash with amazing results. Paradoxically enough, it often means not using a flash when you think you should use it (for instance when it’s dark), but rather when you don’t need to but can add some stunning effect by using it. Such was the case I showed in the post Flash Away the Shadows a couple of months ago. And today I will show you another easy way to use the flash for a special effect.
This is a good way to increase both saturation and contrast for instance when shooting during an overcast day. In addition this method puts increased attention to the main subject. So when you need something like this, you might consider this way of using the on-camera flash for a special effect. In addition – and best of all – it’s very easy to do.
Simply mount the flash on the camera and turn it or or turn on the built-in flash if that’s what you have. On more advanced cameras, usually the ones without a built-in flash, I recommend turning the exposure mode to Aperture Priority, that is you choose an aperture suitable for your subject and the depth of field you would like to have, and the camera will automatically choose a correct shutter speed. You may also choose Shutter Priority, but then you will have to make sure the exposure will be within the range of what the aperture is capable of. As a general rule, don’t chose Program mode as this often – and normally – will set the camera to the synchronization speed for the shutter, and thus destroy what you try to accomplish with this effect.
On a point-and-shoot camera, you will usually set the camera for slow sync. That’s it. The rest you let the camera handle. If you can compensate the flash light, make sure flash adjustment is set to 0, that is neither over nor under exposed.
What happens is that the camera automatically adjusts for the added flash light so the main subject – or the subject that is lit up by the flash – will be exposed correctly. On the other hand, the rest of what is within the frame, further away and not lit up by the flash will be underexposed. The effect, as I mentioned earlier, is increased attention to the main subject as well as increased saturation and contrast.
If you want to understand what actually happens, think of it as two exposures happening at the same time. One exposure is by the flash while the other exposure is by available light or the natural light. Where both flash light and available light lit the subject there will be too much light, since one is added to the other. Thus the camera compensates for this overexposure. It does so by choosing a faster shutter speed (if you have put the exposure mode on Aperture Priority). Changing the shutter speed doesn’t affect the flash, but a faster shutter speed will make the available light darker. So where the flash doesn’t light the subject, the result is a darker exposure.
This much said, you don’t need to understand the underlying and technical function of the camera to make use of the effect. But remember this is for daylight use, not when it’s dark. I used effect for the photo accompanying this post. It’s a photo shot during the celebration of Puerto Rican Day in New York.