What exactly are light meters and do i need one?

[JosephW]

Most of my photography is varied (A fancy way of saying i just shoot random ****/whatever i find.) and i find myself in a lot of situations where the light is too much, or more commonly, too dark, and by the time i've reviewed each exposure and whatever looks best the opportunity is gone; Now i thought a light meter gave you some sort of idea of what settings to use, in terms of ISO, shutter speed etc, but i don't know! Help!

 

[wyogirl]

what camera are you using, most have a light meter built in.

 

[JosephW]

An E-520 but i'm using an external 'cheapo' flash with no light metering (that i know of).

 

[DanielLewis76]

That should have a built in light meter. What mode are you taking your photos on? If M try A or S.

 

[wyogirl]

If you are using flash, then you need a flash meter.

 

[timor]

If you are using flash, then you need a flash meter.

Or you need dedicated flash, which will work with camera systems. External flash meter is slow in operation, will require you to first "pre flash" the scene to get the settings and by then the opportunity may be gone, how you said. External flash meter is more of a studio tool, when you are using multiple strobes.

 

[Designer]

Now i thought a light meter gave you some sort of idea of what settings to use, in terms of ISO, shutter speed etc, but i don't know! Help!

That's true. A light meter, whether separate or in the camera will give you a starting point, from which you then make minor adjustments depending on your intent.

You can also do the same with experience. Based on what you have already learned about certain light, scene, conditions, etc., you can make settings based on your intuition, and then make adjustments after evaluating the first shot. The better you get at this, the faster you can make settings that will give acceptable results in quick shots.

 

[pgriz]

A light meter is a measurement tool. But to use it effectively, you need to know what results you want to see. Tell us more about how you're using the flash and how you determine what settings you want to use.

 

[KmH]

The in camera light meter is only capable of metering reflected light, and cannot react fast enough to and 'hold' the meter reading from a flash of light.

A good hand held light meter can not only meter reflected light, it can also measure incident light and flash.
Some hand held light meters can only meter incident and reflected light, but not flash.

Cameras and dedicated flash units can do auto and semi-auto TTL flash metering. (TTL- Through The Lens)
The camera electronics that control flash TTL exposure can use the camera's metering sensor to gauge flash exposure, but has to be able to communicate the exposure information to the flash unit.

 

[hirejn]

The light meter built into cameras is kind of like a slot machine if you don't understand it, which is exactly why you're having problems. It measures reflected light and whatever is reflected the camera wants to expose as medium gray. The problem is not everything is gray. Black is black, and white is white, and the amount of light reflected is different for every object you point it at. Thus, even under the same light, different objects will meter differently. The camera is adjusting to every scene and averaging it so it renders gray. If you don't understand this or how much to compensate to get the exposure how you think it should be, your exposures will be off.

It can be easier and more consistent. The answer is an incident light meter, which measures the light falling onto the scene. Think back to reflective metering. In a given scene, the light source is generally constant. The same light is falling on a dark subject as a light one. The only difference is the dark subject reflects less and the bright subject reflects more. This fools the reflective meter. However, the incident meter doesn't look at color, contrast or brightness. It measures only the light itself as it falls on the scene. If you have the correct exposure for the light itself, everything under that light will render with true tonality, as long as it's within the dynamic range of the sensor. Thus, one incident reading for the scene, locked in manually, and you can point the camera anywhere that's under the same light and get perfect exposure.

Get a Sekonic. You don't have to get high end. You can start with a basic one like the L-308 or L-358, and get one used instead of new.