Gerald F. Lieberman (I don't know who he
is either) is quoted as saying, "Television is proof that
sight has a definite odor." If your pictures stink, then
maybe you are not setting up your camera(s) or camcorders properly
Camera adjustments come in two steps:
1. Setting up the first camera right
2. Making the other cameras match it
Setting up the first camera -
These are the steps you will take when shooting with a single camera, EFP (Electronic Field Production) or ENG (Electronic News Gathering) style. If adjusted correctly, your camera will match shots taken by the same camera on other days as well as shots taken by other cameras. In theory, that is. In practice, nothing ever matches perfectly, which leads to a lot of tweaking and color correcting during the edit. Still, the best anyone can do with a single camera is to adjust it for optimum operation and hope Murphy doesn't find you in violation of one of his Laws.
Step 1 - Normalize you switches -
Before adjusting your camera, make sure the switches are in the proper places. A free-running camera should be on INTERNAL SYNC, with its GAIN set to 0 dB. BARS should be off, and the power should be switched to AC or battery, whichever is appropriate, and I'm sure you already know how your picture smells when your batteries are dead. (Incidentally, have you ever wondered why dead batteries don't attract flies?) Switch your camera's AUTO GAIN and AUTO IRIS ON. Make sure the the camera lens macro is switched OFF and no lens extenders or attachments are in place (except for a clear glass or ultraviolet filter). Switch SHUTTER SPEED to NORM.
Step 2 - Set the COLOR TEMPERATURE filter
for the appropriate lighting -
Most cameras have an internal color temperature wheel with several colored filters allowing the camera to adjust for:
a. 3200° K for shooting scenes under studio lamps or outside during a sunrise or sunset --- all "warm" light conditions.
b. 4500° K for fluorescent lamp lighting (greenish).
c. 6000° K For bright or hazy sunshine
d. 8000° K For shooting outdoors in cloudy or rainy weather or with a clear blue sky without direct sunshine.
Some prosumer cameras merely have a switch marked INDOOR/OUTDOOR or with a picture of a lightbulb and sunshine.
Step 3 - Adjust WHITE BALANCE -
Every time you power up your camera or change lighting conditions (like moving from indoors to outdoors or even from scene to scene sometimes) you have to "teach" the camera what color white is.
In the area you plan to shoot (and its light), place a white card in front of the color camera close enough to fill the camera's VIEWFINDER screen. If you don't have a white card, then aim the camera close-up at someone's white tee shirt. Try to find someone who has had a birthday recently; yellowed tee shirts will lean your colors towards blue.
Some cameras come equipped with a milky white camera lens cap which you can place over the lens and use as your white surface while aiming your camera at the lit set.
Press your camera's AUTO WHITE BALANCE button and hold it for the required amount of time (probably three seconds).
Step 4 - Set the AUTOMATIC BLACK BALANCE
No, BLACK BALANCE has nothing to do with jury selection in Los Angeles. Just as cameras have to be told what color white is, they have to be told what black is. On most cameras, you simply press the button and hold it for the required three seconds or so and you are done.
You are now ready for "action." Start your VCR and switch the camera to BARS, feeding ten seconds (SMPTE recommends 1 minute) of color bars to the tape. If your camera's encoder is a little off (something that is difficult to adjust in the field), the out-of-standard color bars will highlight the problem, making it easier to color correct this tape during editing.
If you're a real perfectionist, switch off the camera's BARS, uncap the lens, and aim it at a chip chart (a test chart with a scale of gray "chips" or color bars) illuminated by the light on the set, and record this for 10 seconds. This test takes camera optics and other factors into consideration. The resulting video sample can later be compared with standardized test signals, allowing adjustments to be made in post. DSC Laboratories in Ontario, in combination with the Canadian Broadcasting Corp. has developed a neat combination color bar and gray scale test chart slide, (called the COMBI-1) held in a portable light box illuminated by the light on the set. Aiming the camera at the slide and recording the results provides a precise reference signal useful when making color corrections later.
At last, call out your slate and let her roll. (What do you mean, everybody got bored and went home?)
DSP (Digital Signal Processing) cameras have a memory that can store all the settings you have made to your camera. Record these settings now. Next time you use the camera, you can go through a setup menu and select this setting and with one keystroke, reset the camera to the settings you stored. Each day you come back to use your camera, it will operate as if you had never put it down.
Misadjusting the camera on purpose -
Sometimes television is art, sometimes truth, and sometimes it takes some art to create the appearance of truth. The properly adjusted camera viewing a properly lit scene, should create true-to-life realistic pictures. In theory, that is. The real world doesn't come properly lit and the cameraperson has to cheat in all sorts of ways to make the real world register within the limits of his machinery.
If it's too dark, you may have to boost the camera's GAIN to add contrast to the picture. You will also add graininess and to the picture and your color will be muddy. If the scene is very bright, the camera can usually handle it by automatically closing the iris. Sometimes the scene is still too bright or the videographer doesn't want to shoot with the almost infinite depth-of-field found at f22. The solution here is to attach one or more neutral density filters to darken the scene or increase the camera's electronic shutter speed. The former solution yields a more natural effect than the latter.
Excessive backlight occurs when someone stands in a doorway or window and the camera adjusts its iris to make beautiful pictures of trees and clouds with a silhouette of your talent in the foreground. If your performer is important, then hit the BACKLIGHT switch or manually open your iris a stop or two so that the background gets overexposed and your performer exposes himself just fine. Hitting the performer with a little key light (just the light beam, not the fixture) may help too. Remember that outdoor light may be 6,000 to 8,000 degrees in color temperature while your camera light or portable light is probably 3200°K and will need the help of a blue filter to match the blueness of the outdoor light.
If you expect to be panning your camera across scenes with bright windows or dark alleys, you may wish to switch your AUTO IRIS to MANUAL and adjust it for your beginning and end scenes. This way, the whole image won't darken and brighten in autoadjustment as you pan. A typical faux pas occurs where you pan from one couple across an open doorway to another. As the camera grabs a bit of the door's daylight, the rest of your image turns into shadows and silhouettes and will stay that way until the door is totally out of the picture.
Afro-American brides with white veils and wedding dresses do the same thing to a camera; it adjusts for the white of the gown while sacrificing the face. Again, switch to manual iris and crank it open until the face looks good. Conversely, when shooting an auditorium scene where a spotlight illuminates a performer and the rest of the stage is dark, AUTO IRIS may yield a white blob moving around on a dark stage. Again, switch the iris to manual, and this time, stop it down to higher f numbers, darkening the stage completely while perfectly portraying the performer.
And then there is painting with the camera. With the use of filters and misadjustments, you can create an environment that never existed, an image that is half real and half manufactured. Various colored filters can add warmth (coral, yellow, pink), coolness (blue), soft and misty (low contrast and haze filters), blue-sky-with-puffy clouds (polarizing filter), and hazy, sunset, or dark skies (graduated filter).
If you don't happen to have a colored filter handy, you can still "fake it" by white balancing your camera on a nonwhite surface of the opposite color. For instance, to create a warm reddish candlelight or sunset glow to your image, white balance on a pastel turquoise shirt or through part of an aqua gel at a white sheet. Conversely, to create a cold or nighttime effect, white balance on that yellowed tee shirt.
Recent TV cameras have dial up menus that appear in the viewfinders allowing you to strobe through various options, raising or lowering the camera's pedestal (brightness control), gain (contrast), or boosting or reducing any of the camera's three primary colors or combinations of colors. Indeed you can "paint" with the camera. Just don't expect to match the shot with anything afterwards; it's hard to reproduce something totally out of standard.
The above isn't completely true. Digitally controlled (DSP) cameras allow you to "paint by numbers," setting every parameter of the camera digitally and then storing the data in memory. Later, when you want to recall the same settings, no matter how whacky, just recall the memory setting and the camera will pick up where it left off. This is a very handy feature when a camera is used for several different jobs at once, each job requiring a special "tweak" to satisfy the whims or artistry of particular clients. After spending hours softening the picture to hide wrinkles, adjusting colors to enhance the look of foods, it is nice to push a button, store the effort, then shut down for lunch or go home knowing that the push of a button will recall the settings without further ado.
Similar to the camera with digital controls is the PC-based time base corrector (TBC) with digital proc amp and colorizer controls with memories. Say you've shot a tape in the field (maybe it forgot to duck when you took aim) and when you played it back, the talent didn't appear bright enough or was off color (and you weren't shooting Andrew Dice Clay), you could run the signal through your TBC, and make brightness and color corrections, storing the adjustment settings in memory. After editing that scene, you may edit other scenes from other tapes using other proc amp settings. When you come back to another shot from this errant tape, you would call up the memorized setting and it would correct the color etc. in one stroke. Some nonlinear editors (NLEs) also have this feature. Elite Video (www.elitevideo.com 800-468-1996) sells the $650 BVP-4 Video Processor that does most of these tasks.
So much for EFP (Electronic Far-afield Production). Elsewhere on this website we'll address the art of matching studio TV cameras, in theory and in practice. There are many people nowadays that are monitoring their homes with security video cameras, and these use pretty basic settings since the appearance is not as important.
BOX 1 - DSP - Digital Signal Processing Remember the debates we used to have about which were better, chips or tubes? Chips won, and for probably the same reasons, DSP is taking over camera technology.
Digital Signal Processing involves converting a camera's image signal into ones-and-zeroes, then manipulating those digits to modify or improve the image, then converting the binary stream back into an analog TV signal. Meanwhile, camera setup parameters can be set without knobtwiddling or screwdrivers, and then digitally stored, for later recall. Advantages of DSP:
1. Permits excellent picture quality.
2. Setup is relatively easy, quick, and requires less test gear (generators, charts).
3. Control is consistent and drift free.
4. Fewer moving and organic components improves reliability. Digital circuit components degrade less than organic (ie capacitors, potentiometers, and coils) parts over time.
5. Fewer organic parts results in a smaller, lighter, more power stingy package.
6. Controls can be centralized (not necessarily on the camera or "all over" the camera.
7. Settings can be memorized and accurately recalled.
8. Digital components are less affected by shock, temperature, humidity, pollution, and vibration than their analog counterparts.
9. Matched cameras can be maintained with little technical help.
10. Chroma detail is improved, along with better transitions between colors.
11. Digital mathematical algorithms in the camera permit special setups, such as dark detail enhancement, which would take a lot of analog knobtwiddling to invoke or turn off. 12. More digital algorithms suppress cross-color interference (where fine details create false colors).
If you are debating over whether to buy
a used non-DSP camera and a new DSP model, perhaps some of the
above advantages will sway you over to spending the extra bucks
on a DSP model.
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