HOW TO USE THE LIGHT METER IN YOUR CAMERA TO GET A CORRECT EXPOSURE
Learning the basics of photography can seem daunting at first as you're being exposed to so many new camera features and learning how they all work together.
If you're at the stage where you're ready to take on the light meter in order to get a correct exposure, you're probably exploring manual mode on your camera and have a good idea of what the shutter speed, aperture and ISO settings are, and what different effects you'll get from each such as the blurring and freezing of motion with the shutter, and shallow and deeper depth of field.
However, regardless of what creative effect you might be after, one thing you want to remain consistent across the board is a correct exposure and in order to achieve correct exposure, the right amount of light needs to be exposed onto your camera's sensor.
If you look at the rear LCD display, or through the viewfinder, you'll see your camera's light meter which is indicated usually by a line with -3, 0 and +3 with a few increments in-between.
All that the light meter tells you is if the image you're about to take will be over or underexposed based on the amount of available light and your current settings...
Take a look at the video below by the YouTube channel: Jared Polin on Photography Hack: How To Use The Light Meter In Your Camera To Get The Right Exposure...