Freelance Photographer
Seeing things differently
A taker of Photographs - A creator of images

Light Meter Basics...


There comes a time in every serious portrait photographers life when they want to squeeze that last extra little bit of control out of their exposures, IMHO a light/flash meter is the only way to go... My first ever light meter was the Leningrad 8 (shown on the right), this is now about 30 years old, uses no batteries and still gives correct readings... Next to it you will see my Gossen Variosix F which is also knocking on a bit and is superseded by the (youv'e guessed it) Gossen Variosix F2... Again it’s still giving accurate readings and in regular use for taking incident readings (light falling on the subject) and for flash readings...


My advice is “if you are going to buy a light meter you might as well buy a flash meter” as flash meters take incident readings with or without flash whereas basic incident meters do not take flash readings... For this reason all references to hand held meters will refer to flash meters... The exposure meter in your camera is only capable of recording reflected light, which in tricky lighting situations can be fooled because light shiny surfaces reflect large amounts of light and dark dull surfaces absorb it... A hand held light meter can record incident light readings with the diffusing dome on, reflected light with the dome removed and flash output with the dome on... Modern hand held meters are capable of taking readings in aperture (f), shutter speed (t) and Flash modes, you can also set the ISO to the cameras ISO setting and some even have a correction setting to compensate for any inaccuracies...

To use a hand held meter to take incident or flash readings I’ve found my best results have been achieved by placing the meter at the subjects position making sure I’m not in the path of the light and pointing it towards the light source... I can also make any compensation I feel necessary for the medium in which I’m shooting, like under exposing 1/3 of a stop for digital or slide film and over exposing between 1/3 of a stop and 1 full stop for print film to saturate the colours... For studio work I put the meter in flash mode and trigger the flashes to determine the suggested shutter speed and aperture... For example I will use the reading on the meter in the picture above, it reads f/5.6 @ 1/60th of a second at ISO 100, but if you look carefully you will see a figure 7 after the f/5.6 (some meters use a bare code and each bar indicates 1/10 of a stop) which means it is actually f/5.6 plus 7/10ths of a stop... The lens therefore should actually be set at f/6.7 for print film or even left at f/5.6 as print film can benefit from slight over exposure, or you could use f/8 for digital or slide film as digital or slide can benefit from slight under exposure... If your camera has a built in compensation dial you could set the aperture at f/5.6 and use that to dial in a 2/3 of a stop compensation... If the number after the actual f stop is 3 (or 3 bars) 1/3 of a stop compensation is required, if it’s 5 then 1/2 a stop, if its 6 then 2/3 of a stop is required and if its 9 then I would stop down to f/8 anyway...

One thing to remember when using a light meter is that it does not take into account any compensation for filters... So if you are using any filters except the standard skylight or UV which have a filter factor of zero you will need to adjust the camera’s settings accordingly by either using a longer shutter speed or a larger aperture...


Light Meter Advantages...

Below you will see two images taken with a Canon 5D using an 85mm lens in manual mode at 1 second, tripod mounted using a cable release and under exactly the same lighting conditions... I chose to change the aperture value rather than the shutter speed so if there was any blur due to movement it should be the same for both images... The lighting was one modeling light from a studio flash and the colour balance was set to tungsten on the camera with the ISO set at 100... Both images have been cropped and transfered to a new blank image so any deterioration during resizing will be applied equally to both images...

Camera's suggested exposure of f/3.5 Meter's suggested exposure of f/8

As you can plainly see, the image taken by the camera's reading is well over exposed and the one exposed at the meter's reading is spot on, WHY?...

Well, the camera's meter was set to Evaluative and calculated the exposure from the whole area taking into account the reflectiveness of the petals and the bright light source coming in from the lower left...

The incident reading from the meter was taken from the light falling on the flowers thus disregarding the petals reflectiveness and the brightest part of the image where the light source was... The difference was about 2½ stops in exposure giving a better rendition of the true colours and producing infinite better detail in the petals...