While most DSLRs can accurately calculate the amount of flash needed, there are times when the camera will get it wrong and either over-power or under-power the flash. To prevent this, use your camera’s flash exposure compensation function.Your DSLR will either have a button or a menu option – both work pretty much the same as your camera’s exposure compensation. If you select minus numbers, the flash power will be reduced and you won’t lose highlight details. You can increase the flash power by dialling towards the plus side of the scale. This is useful when trying to light subjects that are a little further away, or when the light meter is being fooled by something bright in the frame.While your camera’s pop-up flash can cope with some shots, if you’re planning on getting creative with flash you really need to think about investing in an external flashgun. These give you more power, extra control and features, and produce better results.Flashguns produce strong directional light that can sometimes result in unflattering photos, especially when shooting portraits. Flash can be softened with diffuse material such as tissue paper. While not great in the rain, it’s certainly cheap and easy to use. It’ll produce softer, more flattering results for just a few pence.