You must be aware of the built-in light meter in your camera. The built-in light meter in your camera helps you know the amount of light entering your camera at the exposure settings for that instance. If the light meter reads 0, then it means your exposure is perfect, if it reads – on the scale, then it means that your picture will be under exposed. If it reads in + on the scale, your picture will over exposed. The built-in light meter of your camera gives you a rough idea of your exposure and you need to keep fiddling with your exposure settings, and finally get the perfect one through trial and error. Hand held light meters, on the other hand, are more accurate and precise. They tell you the exact f stop and shutter speed that you should set to get the right exposure.

Hand held light meters basically come in three types. The first one is the incident light meter that reads the light falling on the subject. One such incident light meter is the high quality Gossen Digisix. Incident light meters are held on the face of the subject, at the same angle from which shot is to be taken, and held facing towards the camera. This kind of light meter measures the light falling on the white dome present in it (look at the picture) and gives you the exposure settings for the correct exposure.

The second kind of light meter is the reflected light meter or the spot meter. This meter reads the light that is reflected from the subject and entering the camera. This light meter is held directly above the camera position and it gives the exposure settings for the camera according to the reflected light.

The third kind of light meter is a flash light meter and is a kind of incident light meter. The difference is that it can be synchronised with the flash of your camera and tells you the readings as soon as the shutter is clicked and the light flashes from your flash gun.