Video Camera History

I also wrote from scratch, a capsule history of video cameras, that focuses on their operation. http://en.wikipedia.org/wiki/Professional_video_camera#History

Professional television camera history has two main lines: the gradual shrinking of the camera as it became more versatile and self contained; and a progression of sensors from large insensitive tubes to smaller, much more sensitive tubes and finally to very small, very sensitive solid state chip imagers. Cameras that contained their own recording mechanisms did not appear until the early 1980s.

Early studio television camera -- Gray box on right is the lens, gray box on top is the Viewfinder, sides are lowered to show internal electronics.

At the beginning, these cameras were very large devices, almost always in two sections. The camera section held the lens and tube pre-amps and other necessary electronics, and was connected with a large diameter multi-core cable to the rest of the camera electronics, usually mounted in a rack. The rack would be in a separate room in the studio, or in a remote truck. The camera head alone could not generate a video picture signal on its own. The video signal was output from the rack unit to the rest of the studio for switching and transmission. By the fifties, electronic miniaturization had progressed to the point where some monochrome cameras could operate stand alone and even be handheld. But the studio configuration remained, with the large cable bundle transmitting the signals back to the CCU (Camera Control Unit). The CCU in turn was used to align and operate the camera's functions, such as exposure, system timing, and video and black levels.

The first color cameras (1950s in America, early sixties in Europe), notably the RCA TK-40/41 series, were much more complex with their three (and in some models even four) pickup tubes, and the size and weight drastically increased. Handheld color cameras did not come into general use until the early 1970s, and the first ones were two pieces, a camera head shoulder unit that held the lens and tube section, and a backpack unit. The Ikegami HL-33 was the first of this type, but was followed a up by one piece cameras. These one piece cameras, (The HL-77 from Ikegami and the TK76 from RCA) made possible, in combination with portable 3/4" U-matic VCRs, the introduction of Electronic News Gathering (ENG), which very rapidly replaced the 16mm film cameras that had been the dominant method for capturing news events. This established the standard operation in the field of a two person news crew, one operating the camera, and one carrying the shoulder strapped U-matic recorder and a boom microphone. The control layout for the camera's most important functions was also established with these cameras, and continues to define an ENG camera to this day.

In the early 80s, the first cameras with on board cameras were brought to the market. The far more successful of these used the Betacam recording system. At first these cameras used pickup tubes, and the recorders were of the removable type. Models with CCD imagers came on the scene in the mid-80s. These brought multiple benefits. They were much more stable and less prone to drift than tube cameras, and didn't require a warm up or calibration time at the beginning of the day. They also were not prone to image burn in or streaking caused by bright lights. The early models did not have the resolution or color quality of their tube counterparts, but successive models quickly pulled ahead of tube technology. Eventually, cameras with the recorder permanently mated to the camera head became the norm for ENG.

Studio camera technology did not stand still during this period. The camera electronics shrunk, and CCD imagers replaced the pickup tubes. The thick multi-core cables connecting the camera head to the CCU were replaced in the late seventies with triax connections, a slender video cable that carried multiple video signals, intercom audio, and control circuits, and could be run for a mile or more. As the camera innards shrunk, the electronics no longer dictated the size of the enclosure. But the box shape remained, as it was necessary to hold the large studio lenses, teleprompters, studio viewfinder, and other paraphernalia needed for studio and sports production. Electronic Field Production cameras were often mounted in studio configurations inside a mounting cage. This cage supported the additional studio accessories.

In the late 90s, as HDTV broadcasting commenced, HDTV cameras suitable for news and general purpose work were introduced. Though they delivered much better image quality, their overall operation was identical to their standard def predecessors. New methods of recording for ENG cameras were introduced to supplant tape. Ikegami and Avid introduced EditCam in 1996, based on interchangeable hard drives. Panasonic introduced P2 cameras. These recorded a DVCPro signal on interchangeable flash card media. Several other databased recording systems were introduced, notably XDCam from Sony, and as of 2009, it remains to be seen what will become the predominant method of camera media for professional use in the 2010s.

ENG Video Camera Definition

What's the difference between the big shoulder cameras pros use, and small handheld camcorders? Here's a piece I edited on Wikipedia that I liked so much, I thought I'd reprint it here.

Though by definition, ENG (Electronic News Gathering) video cameras were originally designed for use by news camera operators, these have become the dominant style of professional video camera for most uses, from shooting dramas to documentaries, from music videos to corporate training. While they have some similarities to the smaller consumer camcorder, the following differences should be noted:

* ENG cameras are larger and heavier, and usually supported by a shoulder stock on the cameraman's shoulder, taking the weight off of the hand, which is freed to operate the lens zoom control. The weight of the cameras also helps dampen small movements.
* 3 CCDs are used instead of one, one for each primary color
* They have interchangeable lenses.
* All settings, white balance, focus, and iris can be manually adjusted, and automatics can be completely disabled.
* The lens is focused manually and directly, without intermediate servo controls. However the lens zoom and focus can be operated with remote controls in a studio configuration.
* Professional connectors - BNC for video and XLR for audio. There are at least two XLR audio inputs.
* A complete timecode section is available, allowing time code presets; and multiple cameras can be timecode-synchronized with a cable.
* "Bars and tone" will be available in-camera (the color bars are SMPTE (Society of Motion Picture and Television Engineers) Bars, a reference signal that simplifies calibration of monitors and setting levels when duplicating and transmitting the picture.
* Recording is to a professional medium like some variant of Betacam or DVCPRO or Direct to disk recording or flash memory. If as in the latter two, it's a data recording, much higher data rates (or less compression) are used than in consumer devices.
* The camera is mounted on tripods and other supports with a quick release plate.
* A rotating behind the lens filter wheel, for selecting an 85A and neutral density filters.
* Controls that need quick access are on hard physical switches, not in menu selections.
* Gain Select, White/Black balance, color bar select, and record start controls are all in the same general place on the camera, irregardless of the camera manufacturer.
* Audio is adjusted manually, with easily accessed physical knobs.

Ten Tips for Better Web Videos

The great thing about all the new camcorders out there is you don't have to be expert in the underlying tech to get a great result. Here are some simple tips to maximize the performance out of these small wonders.

First—Get Close - Television isn't quite the close-up medium it used to be, what with the popularity of big screens everywhere. But web video sure is. Get Close! Not chin to forehead close, but upper torso or head and shoulders close. People want to see you, not the junk in the background. If your camera has a zoom, backing the camera up and zooming in, is much more flattering to your features than placing the lens close to your face.

Second — Avoid Backlighting - Windows make horrible backgrounds. Daylight can be 800 times brighter than indoor light, and your camera can't cope. So your subject won't look like a silhouette set your camera so the daylight is coming from the side or behind the camera, but the window isn't visible in the picture.

Third — Minimize Noise - Good sound makes video look better! Web videos sound echo-ey and noisy, because the microphone is on the camera, and not close to the person's mouth. Check to see if your camcorder has an external microphone input. An inexpensive microphone from a Radio Shack or an electronics store that has a good camcorder dept. will work much better than the mike on the camera. A lapel mike like the one shown here is perfect.

Fourth—Use a Tripod - Steady does it! When using a camcorder, avoid hand-holding. Web compression software works better on a steady image, and a stable shot looks more professional all around. You can use a tripod, or even place the camera on a steady flat surface. On top of a box on a table works fine. The camera should be at the same height as your face. If cameras seem to make people look ten pounds heavier, shooting from below doubles that effect!

Fifth—Brighten Up! - The low light ability of modern cameras is astonishing. But if the picture looks grainy or blurry you may need more light. Or you may have plenty of light, say from overhead fluorescents, but everything looks flat. Indirect soft light coming in from a window to the side and to the front of the face, almost always gives a very pleasing look. (But not direct sunlight falling on the face -- and with care not to let the window itself show in the picture!)



Sixth—Move With Caution - The zoom lens is not a garden hose. Moving the camera around and zooming in and out will just give the audience motion sickness and be very hard to edit later. Hold -- roll tape -- pause tape, frame the next shot. If you’re not able to use a tripod, hand-held can work, thanks to cameras with anti-shake features. It's easier to handhold if you stick with a wide angle, brace against a wall or doorjamb.

Seventh—Lots of Variety - Insert shots! Close-ups and cut-aways are the meaty bites of the video stew. Get lots of detail shots of whatever you are describing verbally. Not only are they informative, insert shots break up the monotony of the single talking head shot. They’re invaluable as cut-aways when you need to shorten the video, and cover over the jarring jump in the edit. Hold each shot for ten seconds. It’s a lot easier to edit a shot shorter, than it is to make it longer.

Eighth—The Camera Sees Differently Than You Do - Don’t get the blues. Watch out for your scene looking overly red or too blue. It’s the result of mixing different kinds of light, such as sunlight with tungsten or fluorescent bulbs. Stick to one light source, so your camera's automatic function can balance to that. If you’re still having trouble, check your camera manual, looking for the section on how to set the white balance. Usually it’s a menu item, with Sun, cloudy, bulb or fluorescent tube icons representing different color casts.

Ninth—Not Everyone Can Be Woody Allen - If you're the one in front of the camera it's hard to do a good job behind the camera. Work with an associate who can both operate the camera, and give you feedback on your performance. Rehearse on tape, watch the result together, see what works, drop what doesn't.

Tenth—The Word Comes First - Write out what you plan to say, even if you're not going to read it word-for-word on camera. Writing it out organizes your thoughts, and helps maintain focus on the subject. Rehearse-out all those distracting "uhms" and "you-knows."

How many lights can I plug into this circuit?

You're on location, in a house built in the 1940s. But you're worried about blowing fuses or popping a circuit breaker with the bright and hot lights from the nice Arrilite kit you brought.

You need a way to tell in advance, how to know when the next light you plug in will blow the circuit. You're not an electrician, you heard there was a formula, by some Ohm guy, but you have no idea what it is.

No matter -- There is a simple way to figure this out, and keep out of hot water (and in the light) with the homeowner.

It seems confusing, because the electrical draw of your light fixtures is expressed in Watts, while circuit capacity is marked in Amps. Ohm's Law is an electrical formula that electricians use to make this conversion, but in practical application, you don't really need to use a calculator for this sort of simple situation.

Let's start by looking at the situation in the house. A circuit is a single line of electrical supply, that is usually shared by several outlets or lights in the home. Each outlet is NOT a circuit! Instead, multiple outlets are shared by one circuit. Also, normally, all the outlets or lights in a room are not dedicated to a single circuit. They are usually spread across several rooms. In a two story house, the lights will usually be on circuits shared between floors. This seems illogical, until you realize what happens if the circuits were divided by floor. If that circuit blows, all the lights on that floor go out, and no one can see, until they can find the a flashlight, and get to the circuit breaker.

Fortunately, discovering the capacity of a circuit in a home is easy. First, find the circuit breaker panel. (The following refers solely to 120 Volt electrical service as commonly found in North America.) It might be in a utility closet or it might be on the back porch. If the home has a garage, it is often found there. Upon opening the panel, you'll normally find two rows of black switches, the circuit breakers. These have two digit numbers printed on them, normally a a 15 or a 20. That number is the number of Amps the circuit can safe handle, before the breaker trips off, cutting off the power. If the circuit breaker didn't do this, the wiring in the walls would overheat, and start a fire. This is a special effect we normally want to discourage -- and there are better ways to meet firemen.

If the house is older, built before the 1960s, and never been re-wired, it may have fuses. These are very often only 10 amps. NEVER replace a 10 amp fuse with a higher number fuse, this is very unsafe! If you're blowing fuses, it's for a reason. More current is being drawn than the circuit can safely handle without overheating.

The next puzzle is to figure out which outlets in the house are assigned to which circuits. If you're very fortunate, sometime in the past, someone else already figured this out for you, and filled in the blanks in the circuit description on the circuit breaker panel door. Sadly, we often find that we're the first persons to bother filling in this card. If that's the case, you have little choice but to experiment, and turn breakers off and on to determine which plugs they control. Before you start, make sure there is nothing plugged in or turned on that might be harmed by the loss, or sudden resumption of power. Home electronics, computers etc. Now you could have another crew member walk around the house with a light, plugging it in to every outlet, yelling out when the light is extinguished, as you flip breakers in turn. A slightly more elegant solution is to use a cheap AC outlet powered radio instead of a light. That'll preserve your vocal cords. It also works well if you don't have an assistant--although with a lot more steps as you walk back each time to move the radio's plug. But you needed some exercise anyways, right?

You'll notice too that in addition to the breakers marked 15 and 20, there are other breakers, with higher numbers, and ganged together as one switch. You don't need to test those, they're for high power items that are hardwired, or not plugged into standard outlets, such as clothes dryers, ovens and heaters. If you're lucky, all the outlet breakers will be 20 amp circuits, and the 15 amp breakers are just assigned to ceiling lights. As it is, you may discover that all the outlets in the house are assigned to as few as two or three breakers.

Now that you know what outlets are available on each circuit, all that's left is to figure out how many of your lights you can plug in to each circuit, staying safe, and not popping a breaker!

I use this simple rule of thumb-- Each amp is "equal" to 100 watts of 120 volt power. Now this isn't correct-- but this rule of thumb leaves a nice safety factor, as it's not really a good idea to load a circuit all the way up to its maximum amperage limit.

So if you plug in a 600 watt light, that takes up 6 of the amps on a 20 amp circuit. And if you plug in two more 600 watt lights, the total is 1800 watts, or 18 amps; you're still under the limit, and won't pop a breaker. But if you start with a 1000 watt light, you only are safe for one more 600 watt light -- another 600 watt light would be 2200 watts, and that's over 20 amps, using our rule of thumb with a built in safety factor. But you could plug in another 400 watt light. If you need more than this, you should find a stinger (AC extension cable) and move on to the next circuit.

A word of caution-- Always keep an eye open for what else might be plugged into the circuit. They need to be taken into account too. So if there's a computer that needs to be left on, on the circuit you need for a light, you have to accommodate it's load also. If the computer draws 500 watts, and it's a 20 amp circuit, then you only have 1500 watts available on that circuit. I really really recommend against sharing lights and a computer on a circuit though.

Watch out for these appliances, that draw much more power than most people realize: Hair dryers and curlers, laser printers, coffee pots etc. Laser printers are particularly sneaky, as they don't draw much power till they print, then suddenly you will see a 600 watt surge, and your lights go out!

Most all of this applies also to offices and commercial bldgs-- These often have sub breaker panels on individual floors. Be vigilant about not overloading circuits that might be shared among rooms, or down a hall. You don't want to shut down someone's computer when they're trying to meet a deadline! A gotcha you'll find in offices is a coffee pot on the other side of a wall in a break room you don't know about, but is on the same circuit you've plugged a 1000 watt chimera into!