6 Best Light Meters | March 2017
- rugged double molded housing
- precision silicon photo diode
- includes built-in stand
- comes with storage pouch
- runs on 2 aa batteries
- not great for taking sunlight readings
- advanced illuminance functions
- comparator function with high/low alarms
- works in full sunshine
The Luminous History Of The Light Meter
Photographers have looked for ways to measure light since the earliest days of their craft. The most common method of measuring light exposure back then involved the extensive use of trial and error. This was daunting work when one considers that the early days of photography were awash with photographers making their own emulsions from scratch and experimenting with exposure times measured in minutes, not milliseconds like we have today.
Mass production in the 19th and 20th centuries brought about more standardization. The differences between batches became more narrow, and results became more repeatable. However, even the most diligent exposure tables had their inherent flaws.
Light exposure measuring instruments began to appear in the early 20th century. The most popular of these prototypical instruments was called the actinometer, which utilized a special paper that turned dark upon exposure to light, without the use of chemicals. Photographers took readings by exposing a small piece of this paper to light and then timing how long it took for that paper to reach the reference point provided by their specific actinometer manufacturer. They would then look up the time on a chart and find the balance between aperture and exposure time necessary for the shot. Cameras with built in actinometers arrived as early as 1933.
Early methods such as these required one to make subjective comparisons, which opened the door for egregious error. Other tools were needed to replace them and inventors soon turned their attention to the electric light meter. The most promising early models used magnets that detected electrical currents caused by light radiation, providing a much more objective readout than any previous method. The most important innovation of the era was the Alnico magnet, invented by Tokushichi Mishima in the late 1920s. These are a type of permanent magnet that allow photo-electric light meters to measure the amount of current flowing through them. People have used Alnico magnets in nearly every light meter from the time of their invention through to the digital age. It is responsible for paving the way for all the light meters of the modern era.
Setting Up A Light Meter To Use With A Camera
Modern cameras contain built-in exposure meters that are lightyears ahead of their early counterparts. This causes many amateur and professional photographers to consider an external light meter to be a wasted investment. These internal meters are not without their flaws, however. They may measure the background of the image over the foreground, pick up extra light from reflections, or measure certain colors more strongly than others. This can result in a poorly exposed picture or entire scenes which need to be heavily light balanced in post production. On a professional level, one can find these meters on every single film set, bar none. This shows that handheld light meters are still essential to obtain the best results possible from behind a camera.
Properly using a light meter is less straightforward than it seems. Photographers or filmmakers adapting from the built-in meters in their cameras may need some guidance to start out. The first step to support the best use of a light meter is to prepare the camera. Set the camera to manual mode, and select the desired ISO and aperture settings. ISO is the level of sensitivity your camera will have to available light. A lower number means less sensitivity, where a higher number means more. Higher ISO settings are useful in darker environments in which pictures would otherwise turn out underexposed. Aperture affects the degree to which a given lens's aperture blades will open, allowing in more or less light. Counter-intuitively, larger numbers mean a smaller opening where smaller numbers mean a larger opening. These settings will also affect a photo's depth of field.
Next, prepare the light meter for use. One can do this by matching the ISO number and aperture to match that of the camera. In many units, the sensor is located within a small white dome attached to the meter. Some units have knobs that need to be twisted, while others have windows that need to be opened. Either way, the photographer must expose the sensor to light in order for it to work. The last step is to make sure the light meter is on the proper mode setting. From there, simply adjust your camera's settings as the meter advises and begin shooting.
What To Look For In A Light Meter
The needs of individual photographers and filmmakers will largely decide the features they must have in a light meter. In general, there are a few important things to consider when choosing from among the market's many models.
One of the first things to consider is the range of the sensor. Some meters are ideally suited to handle the natural spectrum of energy produced by the sun, and are therefore best suited for outdoor use. Other meters have been adapted to meet the specific needs of the studio environment. These meters may be more sensitive to a higher range of the cold light found in the studio setting.
Another consideration is the build of the unit. These meters get bumped around a lot when carried in a camera bag. As such, the vulnerability of the unit can make all the difference in the purchase. The most important consideration in this regard is that the housing protects the sensor at all times when not in use. The photosensors within these meters are highly sensitive tools. Exposure to light when not in use can cause them to lose their effectiveness over time, and may produce inaccurate readings.
It is also important to consider the body of meter itself. Accidents and drops happen in real life and on the set. Having a ruggedly designed light meter can help to protect the internal circuitry from drops and scrapes.
Many photographers favor the ability to use the meter with one hand. Some units have detachable sensors that can require both hands for use. Having an attached light sensor on the unit is important for photographers in the middle of a shoot wanting to do a quick light check without putting the camera down.