Taking digital images of snowy scenes and reflective beach scenes often presents many problems. When taking these sorts of images there may be times when over exposure is a problem, which will blow the highlights and make the image too bright. In addition, there may be times when underexposure is a problem, which will make the snow a dull grey rather than brilliant white and make the image too dark. Whether the final photograph is over exposed or under exposed will be determined by how the camera’s internal meter reads the scene prior to the photographer pressing the shutter button.
In order to take successful digital images of snowy scenes or glorious sandy beaches it is important to have a thorough understanding of the digital camera’s internal meter and how it works so you can make the necessary adjustments to overcome the issues.
In a nutshell, the camera’s internal metering system is designed to record a mid tone grey, which reflects 18% of light. Basically, this means that if you set an aperture or a shutter speed, point the camera at the scene and press the shutter button half down the camera will select the appropriate shutter speed (if the aperture has been set) or aperture (if the shutter speed has been set) to make the subject mid tone. In scenes where the average is mid tone, i.e. there are areas of shadow and highlights that are not too extreme you shouldn’t encounter any problems. In scenes where there are really dark shadows or extreme highlights such as snow or reflective sand there is a chance the exposure will be incorrect.
Fortunately, there are a few actions you can take to get correct exposure when taking photos of snowy scenes or golden beaches, which will depend on the specific circumstances.
Let’s imagine you want to capture a landscape scene and most of it is snow. In order to get the required depth of field a small aperture is required, therefore the camera is set to aperture priority mode and f/16 is selected. With the camera in evaluative metering mode point the camera at the scene and press the shutter button half down in order to get the meter working. The camera will select a shutter speed that will make the scene a mid tone, which will render the snow grey. In order to make the snow glistening white dial in one and a half or two stops of positive exposure compensation and take the picture. Arguably, this is the quickest and easiest method to render snow white however the exact amount of positive exposure compensation required will vary from shot to shot. In time you will soon get to know how much exposure compensation to dial in to get the shot you want.
Whilst you are learning how to use your camera it is worth bracketing the shot, i.e. taking the same image with different exposures, in order to get the desired shot. This method will fill your memory card up quicker and it will mean sifting through more images but if that is what is necessary to get the desired shot then so be it.
If your camera does not have an exposure compensation feature then the process is to set the camera to manual mode and set the required aperture, which in this case is f/16. Adjust the shutter speed until the analogue is one and a half or two stops to the right, i.e. indicating over exposure. Compose the shot and then press the shutter button all the way to make the exposure. Once again, you may want to bracket the shot in order to get the best image.
Whilst snow has been used in the examples above these methods are equally suitable for taking images of reflective sand, where if the camera meter is left to its own devices it may lead to incorrect exposure.