Camera Work: Buttons, Blasted Buttons

by Jim Stinson
April 1995

Okay, okay, I confess: my newest camcorder's facing its first birthday and I still can't work all the stupid buttons on it.

Oh, I understand what they do--no, honestly! I just haven't gotten around to figuring out which is which. I mean, I've been too busy cataloguing my lima bean collection and all.

Unless you're an aggressive technoid, your camcorder may also sport several controls whose purposes remain mysterious. But these buttons really do deliver functions worth using, so let's take a fast and painless tour of them. At best, you'll achieve better control of your equipment.

And at least you won't humiliate yourself when your spouse points to a button and asks what it's for.

From the Top
Let's start with three controls so basic that the camera works them automatically if you refuse to do so: focus, exposure, and white balance. By taking personal command of just these three functions, you can eliminate a great many causes of poor quality video.

First on the list is focus. If you've used a camcorder even once, you've experienced autofocus, the function that continuously adjusts the lens to keep the picture sharp. Almost every camcorder has a control that allows you to switch from autofocus to manual.

Why bother? Because the autofocus system, like the scarecrow in Oz, has no brain; it's pitifully easy to fool. Example: as you tape your daughter learning to ride a two-wheeler, she pedals past a light pole in the foreground. Because the pole is much closer to the camera, the autofocus system refocuses the lens on this totally unimportant element, and turns your daughter into a blur. By focusing on your daughter and then turning autofocus off, you can force the system to ignore the light pole and keep her sharp throughout the shot.

Autoexposure
The second automatic feature that everyone uses is exposure. The exposure system regulates the amount of light that gets into your camcorder, so the picture is neither too light nor too dark.

But autoexposure is just as easily fooled as autofocus. Because it can't tell which part of your picture is important, it can't figure out which part to expose properly. Pose someone against a dramatic blue sky and the system will expose the bright sky correctly, turning the darker (though more important) person into a black silhouette.

Different camera models address this problem with different types of controls. The simplest version is a button that's usually labeled "backlight." Pressing it forces the camcorder to let in more light than its auto system tells it to, to give better exposure to the darker foreground.

A more sophisticated control (often marked "iris") lets you dial a bit more light (or a bit less) while you eyeball the effect through the viewfinder. This gives you somewhat more flexible control.

Some top-drawer camcorders offer fully manual exposure. If you're a film photographer who knows all about f-stops and good stuff like that, you can set the aperture of the lens by hand for complete exposure control.

Before leaving the topic of exposure, we need to mention

the "gain" button. This feature (sometimes labeled "gain up") electronically amplifies a dark video image, brightening it enough to be displayed more clearly.

You don't want to press the gain up button except in very poor light because it produces a somewhat coarse and grainy picture. But sometimes it's a life saver. Recently, my students taped a play, a comic murder mystery in which most of the last scene was so dark that their camcorders couldn't see anything. By switching on gain up, however, they boosted the weak video signal enough to get a respectable image.

Balancing Act
Your camcorder's third major automated system is white balance. (I've seen this button labeled "W.B.," which is informative as all get-out.)

White balance is the control that matches your camcorder to the color of the light in which it's shooting. "White" daylight is actually slightly bluish, light bulbs are slightly reddish, and cool fluorescents are slightly a mess--with evil green predominating.

Your brain adjusts to changing tints of so-called white light automatically, but your camcorder depends on white balance to do the job. This control comes in three basic flavors:

Automatic white balance chugs along completely unattended, and some videomakers leave the control at that setting permanently.

Switchable white balance has settings for outdoor, indoor, and often fluorescent lights, offering a greater degree of user control.

Adjustable white balance customizes the camera's color perception for each environment by analyzing the incoming light and adjusting accordingly.

If you've ever taped outdoors with the white balance set for indoor (incandescent) light, the ghastly blue footage you ended up with should have already convinced you of the importance of the white balance button.

Open-and-Shutter Case
While on the subject of controlling light, we need to mention the shutter, which, on some camcorders, has a button of its very own.

Which is seriously strange, because camcorders don't have shutters. The word comes from film photography, in which mechanical shutters control the timing of each exposure. Camcorders have electronic circuits that do the same job, so their designers named that job "shutter speed" in a failed attempt to avoid confusion and tedious explanations like this one.

Many camcorders have shutter speeds of from 1/100 to 1/12,000 of a second. Although the camcorder always records a field of video on tape every 1/60 of a second, high-speed shutter shortens the amount of time the CCD has to gather each image. With the reaction time shortened, each image the sensor records has less motion and hence less blur. Fast- moving subjects become sharper. To see where you need to sharpen the picture, imagine a golf swing.

Videotaped at the normal 1/60 of a second shutter speed and played back frame-by- frame, you can't really see the club at all. You just get about eight frames of blur. But if you tape that same shot at 1/1000 of a second shutter speed or higher, each frame will reveal a sharp, distinct golf club. When you play back in slow motion, you can easily analyze the golfer's form. On the negative side, very high shutter speeds may create a strobing effect when playing back at normal speed.

As for increasing the shutter speed to reduce the amount of light your camcorder has to work with, you can use this to your advantage in two ways:

To improve picture quality in bright light. Camcorders are not at their best in very bright conditions. Colors can "bloom" and smear. Upping the shutter speed reduces the light to a more manageable level.

To reduce depth of field. Depth of field is the amount of real estate, stretching away from the camera, that appears in sharp focus. At very small outdoor apertures (lens openings), this sharp area is extremely deep, and distant background elements sometimes compete with the subject for the viewer's interest. Increasing shutter speed to 1/1000 second or more reduces the light so much that the lens must open to the wider apertures, reducing the depth of field. Thrown out of focus, background features are far less distracting.

To avoid scaring you off, some manufacturers hide shutter speed control in so-called "programmed" exposures that you set by name instead of speed. "Sports" selects a very fast speed to stop action. "Outdoor" increases speed moderately for better picture quality. "Portrait" increases the iris opening while raising shutter speed, the resulting decreased depth of field throwing background elements out of focus. As you can see, you can't discuss exposure without talking about the camcorder's lens, so that's the next bunch of buttons we'll look at.

Lens Control
Only a few high-end consumer camcorders let you set the lens opening manually, but even the cheapest models feature the control everyone can locate: the zoom--whether it's a pair of buttons or a rocker-arm switch.

Push the front part of the control and you zoom in to a tighter picture; push the back part and you zoom out to a wider one. With some cameras, the harder you press, the faster you zoom. Simple!

And here's something simpler yet, and better: the manual zoom control. The manual zoom control is a rarely-used feature found on most larger camcorders; it offers two big advantages over motorized zooming:

It's very fast. Often you need to zoom when you're not taping, to find a composition or to manually focus the lens (you always do that at full telephoto, don't you?). For these chores, the stately pace of a motorized zoom wastes your time and tries your patience.

It burns up battery power. Zoom motors are notorious for draining power and shortening battery life. The manual control uses finger power instead.

Besides, the more experienced you grow, the less zooming you'll do while taping. Professionals rarely zoom mid-shot, and use taste when they do. They appreciate the silky smoothness of a motor zoom at times, but more often use the manual zoom in their work. So when you shop for your next camcorder, don't forget to look for that modest but essential control, manual zoom.

Before leaving the topic, we need to mention digital zoom, a feature found on many better-grade camcorders. Digital zoom electronically increases the ability of the camcorder to magnify the incoming image.

Here's how digital zoom works: within its range of focal lengths (such as 5-60 millimeters), your lens optically enlarges the image by changing the distances between the many hunks of glass inside your lens barrel. The extreme telephoto position provides enough magnification for most situations, but not all. If you're shooting your daughter's soccer game or the moose at the far end of a meadow, you just can't get close enough.

That's where digital zoom comes in. Instead of magnifying the image optically at the lens, it does this electronically at the chip. As you digitally zoom in past the optical limit of your lens, circuits fill the entire frame with smaller and smaller portions of the image- sensing area.

The good news is that digital zooming can extend your range remarkably (some models claim 100-to-1 zoom ratios). The bad news is that image quality degrades very quickly as you zoom. Why? Because a video image is made of tiny dots. In order to fill the frame with just a portion of the full image, you have to enlarge those component dots. It's like magnifying a magazine photograph: after a certain point, the picture breaks down into separate blobs.

And beware: some digital zoom features are manually switchable--but not in my camera. If I hold the zoom-in switch down too long, the camera switches automatically to digital and keeps right on zooming. True, the zoom ratio does have a readout in the viewfinder, but viewfinder information is hard to process, as we'll see further on.

For the Record
While we're out here on the camcorder hand grip next to the zoom control, we should say something about the record buttons. "Record" itself is too self-evident to linger over, but you should know about its companion controls, "record review" and "edit search" (most cameras will have either one or the other).

These controls allow you to review your shots as you go. That's nice in theory, but in practice it has industrial-strength drawbacks. First, it drains battery power. More importantly, it offers a dandy chance to blow away footage by taping over it because you didn't roll down to blank tape before resuming. (Happens to my students all the time.)

While on the subject of recording, some camcorders have another ingenious button: one that disables the little red "recording" light--very useful when you don't want to spook your subjects.

SFX
Many consumer camcorders include buttons that create so-called "DVEs," or Digital Video Effects. The most common are fade out/in and wipe/dissolve. Fancier models add strobe, mosaic, and paint.

My advice: avoid cameras festooned with these toys, for two reasons. First, they're all too easy to hit by accident. You're taping your baby's unrepeatable first steps when your finger slips and turns the little tike into a pattern of squares. Camcorder designers struggle to place the buttons in easily accessible positions. The big problem is that this makes them easy to access by accident as well as on purpose.

Second, when you make an effect in the camera, you're stuck with it. If you realize later, in editing your program, that you faded out too soon, tough tofu, Jack; you can never extend that shot.

Nowadays, all these effects and more are available in black boxes selling for under $200 on the street. It makes much more sense to add these dandy visuals in editing. That way, if you mess something up, you can always do it over.

The exception to all this is the date button. It lets you mark your footage with visible date and time. This is a very useful feature, if you record the date for 20 seconds, disable the date function, and only then start recording program material. Visible date numerals grow irritating if left on through part or all of the program. So remember to look for them in the viewfinder and turn them off.

A Tube with a View
Speaking of viewfinders, these tiny TV sets have buttons of their own. Just like their 27-inch siblings, they have controls for brightness, contrast and (if color) saturation.

Adjusting these little devils can be tricky. The best way to do it is to patch your camcorder to a big and well-adjusted color monitor. Check to see that your camera is delivering a good picture to the big screen and then adjust the viewfinder controls to match.

And here's a finder control that many people miss: the diopter adjustment. When you pick up a pair of binoculars, you probably focus for one eye and then adjust the second eyepiece to focus for your other eye.

A camcorder viewfinder has the same control, usually a ring around the finder barrel or else a slider below it. By adjusting the diopter control, you can shoot without your glasses and still see a sharp picture.

Camera and VCR
We call our video cameras "cam-corders" because they're VCRs as well as a cameras, with all the usual VCR buttons. You don't need to review what stop, play, and pause mean, so we'll omit those buttons here.

But there is one switch that does confuse people: the one that toggles the unit between camera and VCR modes. This control often hides within a door or panel that covers the VCR buttons. Open it and you have a VCR; close it and you have a camera.

Ah, but leave it partially open by accident and you have a zilch: nothing on the machine will work. Nine times out of ten, when a student brings me a live but catatonic camera, the VCR button cover has been bumped.

A Blizzard of Info
With all these buttons and dials and sliders and knobs and rings and rockers carrying on all over your camcorder, how do you know what they're doing?

The upside is that most of them tell you; the downside is that they often do so in the viewfinder--the same viewfinder through which you are squinting in a valiant attempt to see what you're taping.

Different camera models display different types of information; the long-winded story in my camera's finder includes day and date, white balance, zoom position (2x, 4x, etc.), battery condition, tape counter, gain up, autofocus enabled, and shutter speed.

To address this information traffic jam, and to reduce the number of actual buttons on ever-shrinking camcorders, some manufacturers are turning to menu-driven settings on external LCD screens. The idea, of course, comes from personal computers: a single mouse button can select a zillion different functions, depending on where you are on some sub-sub-menu, and where you point and click.

Though this can clean up the camera body and reduce the competition for the finder screen, stepping through the process can be as annoying as responding to a computerized phone system. You know the type: "Hello! You've reached 911. If you're having a heart attack, please press 1 now. If you're being mugged, press 2. If you're already dead, please wait for an operator..."

Fact is, there isn't an easy solution. As your experience increases, you rightly demand ever more sophisticated control of your camcorder. Which means ever-increasing decisions, displays...and buttons.

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