Getting Proper Exposure
If you want to get noticed by an employer, then your work needs to look professional. Images that are over-exposed or under-exposed simply don't cut it. That's why we take exposure seriously when we evaluate your photography. Therefore, we're devoting this section to provide tips and explanations to help you make your shots look great, and to help you succeed in getting a job!
First, here's an important and very simple rule of thumb:
What you see in the viewfinder is what you're going to get!
It's as simple as that - what you see in the viewfinder should look equivalent to the way you see it with the naked eye. But to get the right exposure, you need to understand how to use your camera. In other words, know the tools of your trade! We welcome you to ask if you don't understand something, but a good starting place to find the answers is right here.
We've come up with a checklist that should help you get the exposure right on your camera every time. Memorise the checklist in the order you see here:
ND filter Gain Shutter Speed Iris
First, is your camera in MANUAL or AUTO mode? Sure, AUTO adjusts the exposure automatically, but it can adjust when you don't want it to. The picture might become suddenly lighter or darker while you're in the middle of an interview - and that could ruin your shot! We recommend that you get comfortable using the camera in MANUAL mode and use AUTO depending on the conditions of your shoot when you can't always manually adjust the exposure.
Second, determine the lighting conditions. Are you outdoors under sunny skies, or indoors under incandescent lights? Then, when your camera is in MANUAL MODE, check the position of your ND filter (is it On or Off), check the position of the Gain (is it on L, M or H), check the Shutter Speed, and then finally the Iris. The more you use this checklist, the better your shots will look. More explanations about these functions can be found below.
A few things to remember. Lighting is key to getting your exposure right. But if you have too little lighting, you will always end up with an image that is underexposed. Therefore, you need to anticipate when it will become necessary to use additional lights. If you know that you're shooting a sit-down interview indoors, then it's highly likely you might need at least one additional light. Any professional-looking interview is one that is always lit properly. Sure it requires extra effort, but such effort shows exemplary work on your part, which is what employers, and your instructors, are looking for and what you need to get an A in this class.
Here's that checklist again, but with more explanation. One more time, use the checklist in this order:
ND filter Gain Shutter Speed Iris
Neutral Density (ND) Filter - Is it ON or OFF?
Think of the ND filter as a pair of sunglasses for your camera. You put sunglasses on when you're outdoors under sunny skies and take them off when you're indoors. Likewise with the ND filter. The ND filter reduces the intensity of bright light, and gives you a greater range of f-stops to control the exposure.
Gain: Is it ON or OFF?
The Gain always seems confusing to students for some reason. That's probably because it seems like Gain adds more light to the image. But in fact, Gain has nothing to do with allowing more light to enter the lens. Rather, Gain affects the strength of the video signal; by turning up the Gain, the image will show more detail. This is equivalent to changing the gain in your audio speakers, which is simply increasing or decreasing the volume. That's why Gain is expressed in decibel units (dB), which is a unit of signal strength whether it's video or audio. But too much gain will add 'noise' to the signal. In audio, too much gain (or volume) can distort the audio, making it sound over-modulated; in video, too much gain adds 'snow' to the image, making it look grainy. This is what we mean by noise.
The only reason for you to use Gain is under low-light conditions when you can't get enough light to enter the lens - that is, when the aperture is open all the way and the image is still too dark. You definitely don't need to use Gain when the lighting is more than adequate, especially outdoors under sunny skies.
OK, so now that you know what it is, check to see the position of the Gain on your camera. For starts, the Gain should be OFF - in the L position. Look for the value of the Gain in your viewfinder. If the Gain is in L (or OFF), then you should be able to read it in the viewfinder as 0dB. When set in the M or H positions, then the value for Gain might read 3dB, 6dB, 9dB, etc., depending on how it was preset in the camera's menu. If the Gain is left ON (in the M or H settings), and the lighting is more than adequate (under sunny skies), then you might end up nearly closing down the aperture to reduce the amount of light that enters the lens; the image will be over-exposed no matter what you do. Remember, you only want to use Gain under low-light conditions and only when you've opened the aperture as much as possible. Therefore, when adjusting for exposure, always start with the Gain OFF before you adjust your IRIS.
Shutter Speed
This is another function of the lens that often leaves students confused. The important thing to know about Shutter Speed is this:
The faster the shutter speed, the less light can enter the lens - and the darker the image.
Aperture and Shutter Speed work together to get proper exposure. The Shutter Speed determines how long the shutter is left open. The speed is measured in fractions of a second, e.g., 1/60th, 1/125th, and so on. The shutter speed is a way to control the appearance of moving objects - fast shutter speeds have a way of 'freezing' objects that are moving fast, such as spinning helicopter rotors; slow shutter speeds can blur objects in motion. You can use shutter speeds creatively, when shooting sports to see players more clearly when they run, or when they toss a ball. But remember, the faster the shutter speed, the darker the image. You need to compensate by adjusting the iris. When using fast shutter speeds, it's helpful to use more light.
Check the Shutter Speed in the viewfinder and make sure it's set no slower than 1/60 and no faster than 1/100. Less than 1/60th of a second and you get motion blur; greater than 1/100th and you might notice that you won't be able to get enough light in the lens when you adjust the Iris. So set the Shutter Speed accordingly before you adjust the Iris.
Finally, adjust the Iris
The Iris allows you to control the size of the aperture, which is measured in f-stops. Photographers follow this rule:
The smaller the f-stop, the larger the aperture, allowing more light to enter the lens
Conversely, the greater the f-stop number, the smaller the aperture and the less that light can enter. The Iris is the last setting to make from your checklist. Adjust the Iris until the image in the viewfinder looks similar to the way you see it with the naked eye.
Finally, under low-light conditions, once you've
adjusted the Iris and still can't get enough light in the lens, that's
when you can start tweaking the Gain. But be careful... too much gain
will add noise to the image. If you find that the only way to see detail in your image is to add more Gain, then you really need to use additional lighting.
A Word About Zebra Stripes
In many professional cameras, 'zebra stripes' is a setting that can be used to determine if the image is overexposed. The zebra stripes are not recorded into the picture. But if your image is overwhelmed with zebra stripes, then you can bet the image is greatly over-exposed. Therefore, make adjustments to reduce the appearance of the stripes. Some bright areas of the image, such as desk lights or clouds, might still appear with zebra stripes. You don't have to get rid of all the stripes to get an image that is properly exposed. But you don't want these stripes crossing over people's faces.
Getting the Exposure Right
Sequences
Finding depth in your shots
Panasonic DVX200 Camera Instructions
