Module 20

    

Updated: 01/02/2016

module 20      

 

 

 

The Camera

Viewfinder

 

We are gradually sneaking up on the operation of the total video camera. But, before we can really use one like a professional, there are a few more things we need to cover, starting with -- 


Viewfinder Types

The viewfinder of a camcorder can be a CRT, tube-type (like those used in camera viewfinderthe original TV sets), or (more commonly today) a flat panel (LCD or LCoS) display similar to those in laptop computers.

Unlike studio cameras that typically use at least seven-inch displays, the viewfinders for camcorders must be much smaller. They typically use a miniature video screen viewed through a magnifying eyepiece.

Since camcorder viewfinder images are rather small for high-definition needs, various focus assist devices are available. One technique is the electronic magnification of a small area of the image that can be used to tweak camera focus.

 

Accommodating Left

And Right-Eyed People

With cameras that use side-mounted viewfinders, the viewfinder can often be flipped from one side of the camera to the other for operators who prefer to use their left or right eyes.

When the viewfinder is flipped the image can end up being upside-down, unless a reversal switch is flipped. (This also explains why an image might inexplicably be upside down when you first look in a viewfinder.) flat panel viewfinder

Holding your eye to one of these viewfinders for a long period of time can be tiring.

Cameras employing flat panel viewfinders (which you can view from a distance) can help. This type of viewfinder (pictured here) is also helpful in shooting at very low or high angles.

Flat panel viewfinders can also be used to compose shots that you, yourself, want to be in.  You can simply mount the camera on a tripod and (on many cameras) turn the viewfinder around so you can see it. This approach is useful in "one-man band" situations -- primarily news reports -- where the on-camera talent must set up the shot, roll the camera, and then appear in the recording.

The main disadvantage of the flat panel display is that the images lose contrast and brightness when viewed in bright light.  This can make the camera hard to focus.

Once you get used to their operation, viewfinder goggles thatvirtual reality viewfinder resemble virtual  reality goggles allow even greater flexibility. 

Since the viewfinder is connected to the camera by a long cable, you can easily hold the camera over your head, as shown here, place it flat on the ground, or even shoot backwards with the camera mounted on your shoulder.

The main disadvantage of this type of viewfinder is that, if the goggles cover both of your eyes, you can't see what's going on around you.

For critical, professional work the best "viewfinder" is an external monitor, preferably, a bright, high-resolution color monitor. Even though this type of standalone monitor requires extra power and limits your mobility, it's the only accurate way to check subtle lighting effects and critically evaluate focus and depth of field. 

 

Camera Safe Areas

Because of overscanning and other types of image loss between the camera and the home receiver, an area around the sides of the TV camera image is cut off.
safe areasTo compensate for this, directors must assume that about ten percent of the viewfinder picture may not be visible on  home receivers.

This area (framed by the red lines in the photo) is referred to by various names including safe area and essential area.

Some directors confine all written material to an "even safer" area, the safe title area (the area inside the blue frame in the above image).

Although flat-panel TV displays don't evidence overscanning as much as TV sets that use picture tubes, it's still a good idea not to include important information (such as writing) in the outer edges of the TV frame. ( ▲HDTV overscanning note.)

 

Shoot-and-Protect

As we noted in Module 9, HDTV/DTV uses the 16:9 aspect ratio shown above, and standard TV (SDTV) a narrower 4:3 aspect ratio.

" Most producers are now shooting their shows in the 16:9 format. But, since a large percent of home viewers still have sets with 4:3 aspect ratios, productions need to be shot so they can be used in either format. "


shoot-and-protect masks

As we've previously noted, the term shoot-and-protect refers to shooting scenes in 16:9 while "protecting" the 4:3 area--making sure that it still contains all the essential information. To do this a 4:3 grid (shown in red here) can be superimposed over the 16:9 viewfinder image.

 

Adjusting the Viewfinder Image

Viewfinders need to accurately represent the nature and quality of the video coming from the camera.

Although flat screen viewfinders generally remain accurate, viewfinders that are based in miniature picture tubes (CRTs) can drift over time, resulting in an inaccurate picture.

Because the image in a camera's viewfinder is actually the image from a miniature TV screen, it's subject to dogcam.jpgbrightness and contrast variations.

In addition, with tube-type viewfinders there may also be an electrical focus problem and the occasional lack of proper image centering.

Adjusting the viewfinder image does not affect the video coming from the camera itself; but adjustments to the camera video will affect the viewfinder image.

To make sure that the contrast and brightness of the viewfinder are set correctly, the camera's built-in, electronically generated color bars (if they are available in the camera you are using) can be switched on and checked in the viewfinder.

The viewfinder brightness and contrast controls can then be adjusted until a full, continuous range of tones from pure white to solid black are visible.

If the camera doesn't have a built-in test pattern, the quality of the camera video should first be verified with the help of a test pattern and a reliable external video monitor before the viewfinder controls are adjusted.

Checking Viewfinder Accuracy

It's often a good idea to check the camera viewfinder make sure  that it accurately corresponds in all respects to what the camera is "seeing."

It is not unusual for the accuracy of a viewfinder image to "drift" over time.* CRT type viewfinders are especially prone to this. Problems with viewfinders may have to be adjusted with the help of an engineer or technician.

>>Wearing glasses while using a side-mounted CRT camcorder viewfinder can present problems -- especially in seeing all four corners of the image at the same time.

Many side-mounted eyepiece-type camcorders have a control in the eyepiece to correct for variations in eyesight. This is referred to as diopter correction.

If adjustable correction isn't built in, eyepieces can sometimes be purchased for the viewfinder that can eliminate the need for basic types of eyeglasses. 

 

Camera Status Indicators

To help you keep track of everything you need to know while shooting, video camera manufacturers have added an array of status indicators to viewfinders. (And you thought only things like designer jeans were status indicators!)  

First, there are miniature colored lights around the edges of the video image. Red, yellow, and green are common colors. Sometimes they even blink to get your attention. status indicators

Next, are the indicators that are superimposed over the viewfinder video. Boxes, bars, and lines are common configurations.

Some of the viewfinder messages may be superimposed over the image in plain English (or the language of your choice).

Finally, some camcorders have small speakers built into the sides that announce (again, in the language of your choice) such things as "low battery," or "remaining recording time: five minutes."

>>Because every manufacturer uses a slightly different approach, you need to study the camera guide to determine what a camera is trying to tell you. The time spent becoming familiar with the meaning of these indicators will more than pay for itself in avoiding disappointments and failures.

Viewfinder status indicators can include the following: (The most common indicators are in bold.)

  • a tally light indicating that the camera is recording or "on the air"
  • a low battery warning
  • minutes remaining on recording medium
  • SMPTE time code numbers
  • low light; insufficient exposure notice
  • low-light boost (gain selector switch) circuit in operation
  • indoor/outdoor filter in place
  • zoom lens setting indicating how much further you can zoom in or out
  • auto/manual iris status
  • f-stop setting
  • shutter speed setting 
  • audio level meter showing left and right channels
  • a zebra pattern for setting video levels
  • superimposed masks for the safe area and the 4:3 and 16:9 aspect ratios
  • the presence of customized camera setup profiles to accommodate specific types of subject matter or desired image effects
  • camera warm-up diagnostics

In the next module we'll take up camera prompters.


*Some things are learned the hard way. In shooting a major assignment for a TV station with a camera I wasn't familiar with I shot more than an hour of video only to later find out that the viewfinder had major centering problems. There was no way of knowing that what I had seen in the viewfinder was quite different than what would end up on the screen.  




       Interactive Test      

       TO NEXT MODULE        Search Site         Video Projects         Revision Information           
          
  Issues Forum         Author's Blog/email         Associated Readings         Bibliography             
 
   Index for Modules           To Home Page          Tell a Friend        Tests/Crosswords/Matching       

   © 1996 - 2016, All Rights Reserved.
Use limited to direct, unmodified access from CyberCollege® or the InternetCampus®.

Bottom Bar