top of page

  Teach yourself to use a Light Meter.


                                              By Eugene Struthers

Step by Step Light Meter Start-up guide.


(Based on the use of a Sekonic L358)

Why should you use a Light Meter.


When you shoot in a studio there is more light and reflections that is actually needed, it can then be tricky to get the correct exposure. The professionals don't get stressed out because they use a light meter. In almost all circumstances, they will use a handheld light meter. The camera's built-in meter just doesn't have the necessary capabilities to function correctly in studio lighting conditions. So you want to give it a helping hand, as it will make your job easier in the long run. Every photographer wants a device that will tell you exactly how to set your exposure, it will allow you more time to chat with the gorgeous model. Perhaps find out if she has a twin sister. The light meters that are available today, are simple and easy to use. They make our lives as photographers whether amateur or professional much more easier. Yes, you can take a photo, upload it onto your computer and spend the rest of the day using photoshop to correct and fix the exposure. Makes corrections harder, and time-consuming. It would be more logical to take a picture at the right exposure the first time with a handheld light meter. I use a Sekonic L-758DR Digital Master Light Meter. It takes the stress out of a studio shoot.


How do you use a light meter


There are a few simple steps you need to follow before using a light meter. First would be to understand what an ISO is. How your camera interprets your commands imposed upon it in relation to the end result you would like it to achieve. Firstly you will need to determine a required ISO setting. Enter the ISO given from the camera into the light meter. Let's say ISO 100 is shown on your LCD camera screen, now enter this into your light meter. Now extend the retractable white plastic round dome hemisphere in the front out, pointing it back towards your camera on its tripod. If you are working with a friendly model, ask her to hold the light meter below her chin, even better ask the model to push the trigger button on the side of the light meter while you take a shot to test the flash. The light meter will then instantaneously take a reading given off from the flash from your camera. This reading on the LCD screen of the light meter will then give you the exact correct aperture and shutter speed required to take a crystal clear exposure. Then while the model re-adjusts herself, you step back to your camera, dial in the results from the light meter in manual mode - and "Hells Bells" perfect exposure. After a few practices, you will develop a thorough understanding and come to realise that if you move or introduce more lighting another flash test with the light meter will be required. Changing the shutter speed and aperture as required to compensate.




ISO setting: First set your ISO to match the ISO on your Digital camera (ASA speed), Film. This is done by pressing the ISO 1 button and then turning the jog wheel on the side of the Sekonic L358.Once the wheel is turned you will see the ISO setting indicator change in the righthand corner of your LCD screen. Make it land on the same setting as the ISO of your camera.


Metering for available light: Put your camera on Manual mode, this will allow you to set the aperture and shutter speed making an independent change. If you left it on Auto mode, the camera setting will change according to the amount of light available in a given scene. This is difficult and can fool the camera to not see and acquire information which you need it to store and have in the image. This can be different contrasts in colour, bright dark backgrounds, with a model wearing black clothing etc. In the manual mode, you manipulate the camera's settings and the commands are constant. As a photographer, you want to pick an aperture to use and then measure how much light there is for the aperture. At this point, you may ask the model to just wear red lipstick for her next photo shoot. Just red lipstick and nothing else. I find that this helps with concentration. So while the model slips out of her bikini, you go into your camera bag and get out your handheld light meter. You pick the required aperture and then the camera will display the shutter speed to use with that aperture. This method is called using the Light Meter in "Aperture Priority Mode".


Now for the technical stuff


How to put the Sekonic L358 meter in "Available light" Aperture Priority. 


First, press the Mode button while turning the jog wheel. Keep turning the wheel until you see the "Sun symbol" (Top lefthand corner) encased in a box. Once it is placed in a box, this means that you have placed the meter setting to available light mode. As you turn the jog wheel while pressing the mode button, you will notice that the sun setting has two sub settings. These will be one in which "T" (Shutter speed) is displayed within a box and another where the "F" (Aperture) is also displayed in a box. While pressing the mode button with the sun symbol in a box, turn the jog wheel so that it lands on the "F". This indicates that you would like to have the meter on aperture priority mode. So basically you can dial in the aperture and the meter will suggest an appropriate shutter speed reading for the light you have set it too.


Just remember these simple settings:-


1) Sun symbol in a box (in the upper lefthand corner).

2) Place the "F" symbol in a box as well.

3) Turn the jog wheel until you get the required aperture setting on the display.



Go outside into the open sunlight. Turn the jog wheel on your Sekonic L358 until it reaches F11. Retract the white dome lumisphere out and point it towards your light source, in this case, it will be the sun. Keep a steady hand and then press the trigger activation button on the side. The display screen will now indicate the correct shutter speed to use. Now input these two "Aperture" & "Shutter speed" into your camera. You are now ready to capture your first image. But please be aware of the available weather, as conditions can change very quickly and you may just need to take a new reading.


How to put the Sekonic L358 meter in "Available light" Shutter Priority Mode.


This mode is used mostly for circumstances when you don't mind what aperture the meter is automatically set too. Without stating the obvious this would be ideal for sports and action photography. Objects which are projected, people moving at high speeds. You want to shot at say 1/500 and let the meter advise you what aperture to set your camera to. This is using the meter in Shutter priority mode.



This is how you do it.


Similar to the "F" setting as discussed above. We now press the Mode button, while turning the jog wheel until the sun symbol (Upper left hand corner) is encased within a box. Now keep turning the jog wheel so that the box lands on the "T". This indicates that you would like to have the meter on shutter priority mode. By simply turning the jog wheel until you see the required shutter speed. Now aim your white dome lumisphere at the light source keep a steady hand and then press the trigger activation button on the side. The display screen will now indicate the correct aperture setting to use.So basically you can dial in the shutter speed and the meter will suggest an appropriate aperture reading for the light you have set it too.


Metering for Strobes


To make this simple and inexpensive, use a sync cord with one end attached to the flash/strobe and the other attached to the meter. Set your camera to 1/60 Shutter speed. Leave it on this for now. Most cameras will sync with strobes at this shutter speed.


Now for the technical stuff


How to put the Sekonic L358 in Flash mode


Press the Mode button, while turning the jog wheel until the box is around the lightning bolt symbol with the letter "C" figure. This letter C just means that the meter will trigger fire your strobe when a sync cord is attached to the meter and the strobe. The lightning bolt with the letter "T" is used for a wireless trigger and the lightning bolt on its own is used when you trigger the strobe manually without a sync cord. More on these two later. Lets first understand the concept of what we want to achieve before going too far ahead into the technical stuff which may cause confusion at this stage. Okay; back to the lightning bolt with the letter "C" figure. Once you have this you will have the meter in flash mode. Release the mode button and now input the sync speed. This is done by turning the jog wheel until the speed is displayed on the lefthand side of the LCD. It will appear on your display screen as 60 and not as a fraction 1/60.


Ready for a Test:-


Position your meter within the required shooting area. Retract the white lumisphere dome out. Pointing it out towards your main strobe. Press the trigger activation button on the side of the meter. Your strobe light should now fire. The meter will instantaneously pick up this flash reading and recommend a relevant aperture to use on the display screen. So now you have the ISO:-100, Shutter speed:-1/60, and aperture taken from the Meter LCD display. Let's say Aperture:-F11. You are now looking and feeling like a professional. But before I forget, you will want to apply one exception. You will have to remove the sync cord from the meter, and attach it to your camera's sync terminal. So that a connection is made between the strobe and your camera. It is now time for you to call the model onto the studio set. Simple and easy, isn't it?. You are ready. Your only concern now is where to have lunch. Okay; but you get the picture. Excuse the pun. No use complicating the situation if we now have the technology to make it easier for us and we can deliver excellent results. Yes I know we can use standard ISO, Shutter speed & Aperture settings when in a studio. But this can become more complicated once we introduce a second or third lighting source. Each at different power light strengths. This will just be too much information for your camera to handle. Uncomplicate your skills as a photographer, by puchasing a reliable "Light Meter".

                       Sekonic L-308S: Getting Started                                                        Sekonic L-358: Metering Strobe

         See you all

next month

bottom of page