Guest Entry – Is a Hand Held Light Meter Really Necessary?
Written by: Tiffany Joyce
This guest post is kindly provided to us by Steve Russell. You can contact Steve at firstname.lastname@example.org.
Is a Hand Held Light Meter Really Necessary?
By: Steve Russell
Recently Tiffany Joyce posted an article about determining correct exposure by reading histograms. She opened the article by questioning the need for the use of a hand held light meter. While I understand and agree with the point she was making, my reaction was more along the line of, “Wait a minute, I have a hand held light meter and find it useful under certain circumstances.” It’s not my most important piece of equipment, but when I need it, I’m really happy to have it.
After reading her article, I contacted Tiffany and during a back and forth exchange of thoughts and ideas through email we decided that I should write this article on the subject of hand held light meters, so here goes.
I would estimate that roughly 90% to 95% of the people that own cameras don’t need a hand held light meter. The features and functions built into the camera generally provide what the person taking the photograph needs to obtain an acceptable image. When the camera doesn’t expose the image properly the average person taking the photograph typically doesn’t know why and merely deletes the image. However, the other 5% to 10% that step up and purchase a DSLR, usually learn more about photography in general and demand more from their photographic efforts.
A photographer only has two variables to work with – light and time. Time is linear and mathematical. We understand time from early childhood and even the most inexperienced beginning photographer can quickly grasp the importance and operation of time in photography. Light, however, is a much more difficult concept and its understanding is critical to successful photography.
Different sources of light have different color temperatures. High color temperature light sources (like the natural outdoors light on an overcast day) are on the blue end of the light scale. Low color temperature light sources (like a candle flame or an incandescent light) are on the red end of the light scale. Since this isn’t an article on the color temperature of light or white balance settings I won’t go into greater detail but wanted to use this to emphasize the importance of fully understanding light.
A hand held light meter is normally used to measure incidence or ambient light – in other words, the light falling on the subject. The metering system in a camera measures reflective light, or the light being reflected off the subject into the camera. Most of the time there isn’t a measurable difference in the two readings – hand held light meter vs. in-camera meter. However, there are times where you will encounter difficult lighting situations and an incidence light metered reading would provide a more accurate exposure setting. In these cases a light meter can be quite useful.
Both metering tools provide a reading that is the correct exposure for 18% gray. In simple terms that means that both the meter and the camera are color and shade blind and try to read everything as gray. As a result, when you take a picture of a snow covered field the camera reads the snow as gray, underexposes the shot and renders the snow as gray in the resulting photograph. The hand held meter returns an exposure that properly exposes 18% gray as 18% gray and would properly expose the snow as white. This is because, unlike the in-camera meter, the hand held meter is reading the light falling on the subject, not the light reflected by the snow.
As Tiffany pointed out, reading and adjusting the histogram will solve the problem. However, I can pull my light meter out of my pocket, take a reading and take a photo faster than I can take a photo, switch to the histogram on my camera, adjust the exposure, recompose the picture in the view finder and take second photo.
The problem is reversed with black subjects. Let’s say you want to take a photo of an American Bison or a black bear. The head is black, the nose is black and the eyes are black. Remember that the in-camera meter will read the black as 18% gray and the photo will be overexposed. Again, the incidence light will give a correct reading
Now, put the two extremes together in a single photo and where do you acquire the exposure? While you have a number of choices, if you’re in the same lighting as your subject, the hand held light meter will give you the correct exposure. Or using Tiffany’s example of the professional wedding photographer who can hold the meter next to the group, the hand held provides the correct exposure without having to worry about white dresses, black tuxes and different skin colors. Again the histogram works, but the time spent reading a histogram could cause you to miss the perfect photo.
While writing this article, I got to this point and asked, “What if I’m wrong? What if all the advancements in technology, software and algorithms have actually compensated for these exposure issues?” A good question with a relatively easy answer. Why not test my beliefs on this subject. Unfortunately, I couldn’t find any snow and since I live in Florida I can’t even find snow in January. To substitute for the snow, I decided to photograph a white building in direct sunlight.
For the first photo I used the manual setting on my camera because I wasn’t using a tripod and wanted to use a fast shutter speed of 1/500 seconds and an ISO of 100. The first photo was taken using the reading of f8 from my hand held light meter. Note that the building is white without being overexposed or blown out. Also the door is red and looks like it was painted by someone that would rather be in an air conditioned room.
The second photo was taken with the camera set on Tv (shutter priority) at 1/500 seconds and an ISO of 100. The in-camera meter adjusted the aperture to f16 and I took the photo. Note that now the building appears gray in the photo, not the white my eye was seeing when I looked at the building.
There is also a situation where I believe a hand held meter is an absolute requirement for good photography. I’ve discussed this situation with a number of professional photographers and they all completely agreed. In a studio setting when you are using strobes, if you want to capture the best photos with the optimum lighting, you have to hold the meter near your subject (or where the subject will be) and fire the strobes to take a flash reading. Without using the hand held light meter, it will take a lot of trial and error to get the picture correct. I recognize that a photographer that works in the studio day-in and day-out probably knows that if the lights are in a certain position an f-stop of 5.6 is required and if the lights are moved to position B an f-stop of 8 would be required. However, for those of us that either use a make-shift studio or, in my case, a friend’s studio, the light meter saves a lot of time and disappointment.
As a footnote, in the middle of writing this article, my twenty-five year old Minolta light meter died. After a lot of research and discussion with other photographers, I purchased a Sekonic L-358 light meter as seen in the photo below. The new meter is the one I used to take the photos accompanying this article.
Photo credits (all): Steve Russell
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