Philips three-tube colour television camera

A Schneider Variogon 1:2/17–170 mm zoom lens inside a fibreglass shell.  The shell stops anything from fouling the mechanics of the lens, and has a small lens hood clipped onto the front of it.  Unfortunately it's suffered a few cracks and bits have flaked off over the years; so, like everything in a studio, it's been bodged back together with gaffer tape.  Underneath are a couple of mechanical cable drives for the zoom and focus controls, an electrical connector for the iris motor, and at the back you can see levers which are used to rotate the bayonet locking rings that holds the lens, and range extenders, in place.  The lens is around two feet long with all the extenders attached.

The lens can be detached, and range extenders can be inserted between the lens and the camera head.  I have three 2× extenders, that can be used together or individually.  When stacked together, I can use the camera to take full screen pictures of the moon.  Though the quality of the optics degrades when used that way, and you lose a lot of light through all the lenses.  I'm not sure if stacking them makes a 6× extender, or an 8× extender (2×2×2), though I suspect the latter.  Which would, either turn the zoom lens into a 102–1020 mm lens, or a 136–1360 mm lens.  I don't know if the maths works that simply, and I can't recall the specifics of stacking extenders.

On a studio camera, the operator stands behind the camera and operates it entirely from that position.  As such, they can't reach the lens, and need something to control it from the rear.  This camera uses mechanical cable linkages (a cable rotates inside a sheath) between the lens and the controllers.  This is the focus controller, it looks a bit like motorcycle accelerator.  Rotating it moves the focussing elements of the lens.

The zoom controller has a different design.  It's made so that you can easily wind it through it's whole range without having to change your grip for each rotation.  Both the focus and zoom controllers are geared, and require several rotations to run the lens through its full range.  Rotating it moves the zooming elements of the lens.  The gear ratio is fixed, you can't change it.

A downwards tiltable, but not upwards, nor rotatable, monochrome viewfinder, with the usual contrast and brightness controls, and a peaking switch that crispens the picture to aid with focussing.  The design's shockingly bad, considering the flaws are glaringly obvious and unneccessary (not being able to tilt up, nor rotate, and being back-heavy—it's unbalanced and needs firmly locking into position).  Below are buttons to select what's displayed out of, the red signal, green signal, blue signal, luminance signal (panchromatic summing of the red, green and blue signals), negative green (for summing with the red or blue signals when registering the camera), and an external video input (e.g. for monitoring an effects feed from the mixer).  Next to them are the intercom controls, with volume levels for listening to program audio, engineering and producer talkback, a microphone mute switch, a call button, and two headset sockets (e.g. one for the operator, and one for a grip—an additional camera operator who moves a camera, gripping whatever it's mounted on, and pulling or pushing it around).  They're wierd sockets, I've never seen anything like them, and had to bodge in extra connectors to be able to plug headsets in.

Controls for operating the iris, gain, pedestal, black and white balance, from the back of the camera, without a multi-core studio cable.  Either this module is inserted into the camera for stand-alone use, or it's replaced with the multi-core cable connector module for studio system use (see the last picture on this page).  When the camera is used with this controller, the operator has to remove the side panels for registration alignment, and to switch on colour bars.  Even when using the remote controls (see below), the lack of complete controls on the remote units means that camera alignments need to be tweaked at both ends (e.g. for some stupid reason, Philips didn't provide remote genlock phasing controls; technical directors are lumbered with telling a cameraman to tweak controls over the intercom while they watch a waveform monitor, making what ought to be a five second job overly complicated).

Engineering controls for remotely adjusting the electronics in the camera (iris, pedestal/black level, black balance, white balance, colour temperature switch, gain, registration).  Also includes an “on-air” tally light, intercom, a local/remote changeover switch for controlling the camera from this controller or another one connected through it (see the CCU panels below), and colour bars, greyscale, or normal video output selectors.

CCU panels for remotely adjusting the electronics in the camera (iris, pedestal/black level, black balance, white balance, gain, registration).  Also includes an “on-air” tally light, and a switch on the iris/pedestal control (by pressing it down) that can be used for switching the camera to a preview monitor.  The large iris/pedestal control knob slides back and forth for adjusting the iris between two preset levels (preset by the small knobs at each end of travel).  This lets an operator easily adjust between a maximum and minimum as needed by the job, without going all the way from fully open to fully closed.  At the base of the grip is a knob that rotates for controlling the pedestal (master black / video set-up level).  Unfortunately, the black and white balance controls have got noisy and grotty with age, they require a bit of coaxing to get them to do what you want.  For some odd reason there's no headset socket, you'd need to tap into the intercom with something else.  The adjacent picture shows panels for operating two television cameras, that's why there's two of everything.

On the left-hand side of the camera are the video signal amplifiers and controls.  This where the image signals from the camera are turned into useful video signals, the levels amplified and controlled so that the separate red, green, and blue, video signals are at the appropriate levels with each other to produce a proper colour picture.

The circuit board hinges back to reveal the cavity where the camera tubes are (1″ Plumbicons, I think), in the middle of the camera body, behind a black metal shield.  An educated guess would say it provides some shielding against signal interference as well as light leak.

The shield can be removed, revealing the video pre-amplifier board between the three tubes (blue on top, green in the middle, and red at the bottom).  The tubes are arranged around a prism block that's used for dividing the incoming image between the three camera tubes.

Between two of the tubes you can see three capacitors.  These aren't the originals (they got cooked over the years).  They're the main power supply filter capacitors, they're temperature sensitive, and are stupidly placed right above something that gets hot, as well as being strapped to something that gets hot.

Swinging the circuit board back, you can see that with the exception of a modification for the iris circuitry, the board uses ordinary discrete components, there are no special parts.  All the wiring goes back into the camera alongside the hinge, the camera is fully functional with the board swung out.  A lot of that wiring is for the remote control of the video signal settings (black and white balance, and the iris).

Then, on the right-hand side of the camera is the scanning circuitry, and the beam switches (the three small black bits at top of the metallic rectangle), allowing you to turn each gun's beam off individually.

This board also hinges back, revealing the other side of the camera tubes (behind another black shield), and the back of where the encoder cards and multi-core connector are housed (they slot into this frame).

Removing the shield shows the three camera tubes, blue at the top, green in the middle, and red at the bottom.  They each have worm drives that rotate the tubes, and focus them by adjusting the distance between the tube and the prism block (and, therefore, the distance between them and the lens).

Unfortunately the tubes don't lock into place, and vibrations move them out of alignment, particularly the red tube at the bottom.  I don't know if that's typical for this model of camera, or just this particular one.

This is a closer view of the blue tube, showing the connector at the top, the rotation knob in parallel with the tube (pointing to 11 O'Clock), and the focus knob below it at the end of the black plastic section (pointing to 2 O'Clock).  Left of that is the other side of the power filter capacitors, and below them you can see the focus knob on the green tube.

At the back of the camera, under the viewfinder, there's four removeable modules.  The first one holds either the multi-core camera cable connector, with colour bars and greyscale ramp switches, an apparently unusable video connector, and a mains out flylead to the power socket underneath.  Or this can be swapped for a module with local controls for the iris, gain, pedestal, and black & white balance controls.  Next to that is a PAL colour encoder module, with a composite video output connector.  Next to that is the colour sub-carrier generator, with a control for adjusting the phasing between the camera output and the genlock input (either the one on this module, or through the multi-core).  And lastly is a CCIR sync module, with a control to adjust the horizontal phasing between the camera output and the genlock source.  Underneath, and unshown, is the mains power input socket, power switch, fuse, and a combined tally and intercom connector.

Just about everything connects through the base rack unit (so called, because it's a base unit that's installed into a rack of other equipment, usually).  The camera connects to it via a very thick multi-core cable.  All other studio equipment connects to it (intercom, tallies, video signals, etc.).  The first camera control unit connects to it, with another multi-core, and other controllers connect through the first one.

In a studio system, each camera is aligned to a standard, or special configuration, so that all of their pictures go together nicely, with no unwanted changes in tint or exposure, etc.  This is best done with remotely adjustable cameras, with all the remotes under the control of a technical director or vision controller (those are job titles, not more technical equipment).  Using measuring equipment (waveform monitors, vectorscopes, and a reliable video monitor), they'll adjust everything to work properly.