Alan Hoida road tests the Unitron MSX Portable Video Studio and is impressed by its versatility.

So far in this series, we've been discussing ways in which we can make a demo-video using a single camera and editing down the shots.

However, you may need to record a band's live gig, and in that situation there's no time for re-takes and no miming to playback. In order to get changes of angle you'd need at least two cameras and recorders and some means of synchronising the two. The shots can then be edited down as usual. Using professional equipment and synchronised timecode recording, this isn't a problem, but if you're using 'domestic' equipment it's fraught with difficulties.

An alternative method is to do a 'live' studio mix, using cameras which synchronise into a vision mixing console. The pictures are then mixed on the spot and recorded onto whichever format of video system you choose to use. The great advantage here is that you can then introduce no end of effects into your mix via the mixing console. Your master recording is also just 'first generation', as no editing has been involved. But the great disadvantage is that on a live gig, your skill and judgement will really be put to the test as there's no going back for retakes.

As expected, there's a catch.

The professional equipment is very expensive and 'domestic' equipment just isn't designed with synchronisation for mixing in mind. However, it's possible to upgrade 'domestic' cameras and companies like Unitron are doing just that.

Before I go any further it may be of use to those of you readers who are new to video if I explain the basics of vision mixing. You may ask, why it's not possible to plug in two cameras and switch either one into a recorder? Well you could, but each time you switched, you would get a picture disturbance due to the loss of synchronisation.

In order to switch cleanly between one video source and another, both sources must be synchronised so that both are scanning at exactly the same place at the same time. This 'genlock' is achieved by using one camera as the reference source, and feeding the synchronising signal to the other camera (or cameras) via the mixing console.

The Unitron MSX System

What Unitron offer is a complete kit, enabling a 2-camera, portable mini studio to be set up at a live gig or in the rehearsal studio.

At the heart of the system is the MSX console which is a compact desk top controller providing both audio and video mixing facilities. The video facilities available include a variety of wipes, dissolves, colour fields and key effects.

The cameras used are top range 'domestic' type, single tube cameras, which have been specially adapted to provide genlock, tally and talkback.

The complete kit contains the MSX console with full preview and programme monitoring, two cameras and tripods, three talkback headsets, two microphones and desk stands and all the necessary cabling. Extras include a flightcase and even a lighting kit. Several variations of the kit are offered, all based on the MSX console, but offering fewer accessories for those with a lower budget or those who may wish to modify their own cameras, using a conversion kit.

Unitron seem to be into doing 'specials' for their customers, and so you should have no problem in getting exactly the right set-up you want.

The Cameras

At present Unitron are using the JVC GXN70 camera body. The modification is so neatly carried out that I think the camera both looks and balances better with it.

The GNX70 is at the top of the camera range and is certainly capable of very good results from it's single 2/3" Newvicon-type tube. The lens is an f1.4, 8:1 power zoom, with automatic or manual iris, and auto focus is by infra-red with manual override. A neutral density filter can be switched in and a similar switch will set filters to compensate for daylight/tungsten lighting. White balance can either be set to a standard or can be set more accurately by pointing the camera at a white card and pressing the appropriate button. Before a recording session starts both cameras should be set up side by side and a running check made through all these adjustments so that their outputs will be properly matched. There is a knob on the back of the MSX black conversion box on Camera 2 only. Turning this knob will enable a fine phase balance to be achieved between the two cameras. I found in practice that fine tuning of this knob was essential to get a fully colour-saturated picture out of both of the cameras.

The adjustable viewfinder houses a 1" B/W CRT and a series of illuminating letters give indication of exposure, tally, focus and white balance.

The handgrip contains the controls which are used when the camera is connected directly to a video recorder and most of these are not in use when connected to the MSX console. The controls which do not connect are the zoom switch, the auto focus and the display switch, which activates the titling, date and stop watch functions of the camera. By sliding back the cover of the left hand side of the camera body, the display keyboard is revealed, and using this, you can display full alpha/numeric titling superimposed over the image coming through the lens. By capping the lens, the titling appears on a black background. A memory will store up to 8 pages of titles and a date and stopwatch function can be switched in.

The titles can be coloured red, green, blue or white and the entire image can be phased to negative. This enables titling against a white background and also gives a very strange effect when the picture is turned to negative, particularly when added to other effects via the mixer console.

Both the subject and the cameraperson are given clear indication of which camera signal is recorded via the mixer. A red tally lamp is fitted to the front of the camera viewfinder and a red letter 'R' illuminates inside the viewfinder. This is most useful as the subject will then know which camera to perform to if necessary and the camera-person will know when he or she is 'on air' and direct the camera movements accordingly.

The cameras each send their signals via a single ½" diameter cable which connects via a locking, 10-pin connector on the rear of the conversion box.

Both cameras sit very snugly on the shoulder using the fitted extending shoulder brace. Two tripods are also supplied which have rather a clever mechanism that enables them to be manipulated smoothly. Even without any fluid mechanism (which is very expensive), they enable a remarkably smooth pan and tilt. The tripod head incorporates a spirit level, to aid levelling the tripod, and a reasonably long pan bar is fitted, which gives very good control over camera movements.

Vision Mixing

The MSX mixing console is very neatly finished in brown and beige enamel and a lot of thought has gone into the design and layout. All the controls are clearly marked and routing paths are also marked between the controls to aid the logic of the operations. This is quite important as, until one has gained the experience, it's only too easy to lose the route of your signal and get the wrong effect - very embarrassing on a live recording.

Basically, the MXR is a 2-channel mixer and there are three inputs to each channel. Illuminating press buttons on Channel B provide for Camera 1, Camera 2, or a key source. Similar buttons on Channel A provide for Camera 1, Camera 2, or an Internal Colour Field. What you are in fact doing is switching between whatever source is selected on Channel A to whatever source is selected on Channel B and vice versa.

Wipes between channels are achieved by two permanently linked sliders, and mixes between channels are achieved by a single slider.

I've summarised the basic effects which are available on the MXR, but further permutations are available between the effects themselves. As you can appreciate, only 'hands on' experimentation can do justice to these more specialised effects. So much is down to personal taste and inventiveness.

A mix between channels is done by simply drawing down the mix slider. The picture on one channel will gradually dissolve into the picture on the other. Likewise, drawing down the wipe sliders will replace the picture on one channel with the picture on the other, according to a pre-determined pattern. This pattern is selected by a rotary effects switch. There are several wipe patterns available: horizontal, vertical, corner to corner, centre rectangular and St. George's Cross. All the wipe effects are 'hard edged' and occur cleanly without any sign of 'tearing'.

An input for external effects is available and Unitron tell me that they're developing an add-on effects box to use with this input. Anticipated effects are a 'soft wipe', a 'variable box' and maybe a 'circle'.

Then we come to Colour Field Effects.

A Colour Field is an electronically generated colour. The single colour is selected by a rotary knob and a smaller rotary knob varies the luminance of the selected colour. Several colours are available: blue, magenta, red, green, cyan and yellow.

Let's take an example of using the colour field. You could select either camera on Channel B and select a colour field on Channel A and by selecting a rectangular box wipe, a coloured frame can then be wiped onto the Camera image.

Key Effects

A 'key' is the term used to describe the effect whereby the highlights of one picture are used to cut a hole in another which may then be filled with colour. The three key effects are selected by a rotary switch. On 'Normal Colour' the key image is coloured by the colour selected on the Colour Field Control. On 'Matte' the key image is rendered in black and white, the luminance being varied by a 'Key Luminance Switch'. On 'Complementary Colour' the key image is colourised in two complementary colours; the background as selected by the Colour Field Control and the key image in the Complementary Colour. The new variations available therefore become: yellow/blue, red/green and cyan/yellow.

An example of the use of a key effect could be to have a face on Camera 1 with plenty of highlight area. This area could then be colourised, or turned to Matte.

The console also contains it's own black burst generator which enables a fade to, or from black, by a single slider control. Useful.

"I would suggest that if buying the complete kit, you ask for some modifications to suit the particular needs of making demo pop videos."

Monitoring

The top range Unitron kit comes with four Panasonic Quintrix 8" TC 801G Colour Monitors. This may seem excessive but I think that four are necessary to maintain full control.

The bottom two monitors show the outputs from Camera 1 and Camera 2 respectively. The top left monitor gives a preview of any effect you may wish to rehearse before committing it to the programme output. The top right monitor shows the programme output from the mixer.

In practice, this means that on a live recording you can view the output from Camera 1 for example, which you're recording, whilst practising a Key Wipe to Camera 2. When the right moment arrives the wipe can be committed to the programme.

The preview is selected by a row of three illuminating buttons, selecting Camera 1, Camera 2, or Wipe, and the programme output is selected using a set of three illuminating buttons, selecting Camera 1, Camera 2, or Mix. To do a straight cut between Camera 1 and Camera 2, the appropriate word is pressed. To achieve any of the mixes, wipes, or effects, the mix button is pressed. A word of warning though; it's easy to slip up here. For example, if you have Camera 1 selected and next wish to wipe Camera 2, be sure that the wipe slider is in the 'up' position and that Camera 1 is selected on Channel B, and Camera 2 on Channel A. If the wrong Camera is on the channel, pressing the mix button will give a cut to Camera 2 and your wipe will go the wrong way!

The cameras came equipped with their own unidirectional microphones. These don't work when connected to the MXR mixer, so I'd not even bother to fit them on.

Unitron supply their own omnidirectional electret condenser microphones and stands, which are certainly much better than the camera mics. However, I don't see much use for these in our field, as we'll nearly always be recording from a PA mixer's direct line out or from a playback of recorded music. If you did want to record direct, you'd probably want to use your own microphones and mix down to a single output via your own mixer.

The MXR console has its own audio mixing unit, which, although it's very basic (three channels into one with LED indication on the master slider), is fine for our purpose. Mostly it will simply be used for getting the right recording level from our single line input.

Talkback

When recording live, it's essential that the director can communicate his direction to the camera operators, and Unitron supply three talkback headsets for this very purpose. The director can plug his into the MXR console and the line is fed via the camera cables to the camera operator's headset. These are connected via 3½mm jacks into the camera back. In practice, this enables all three to monitor the audio output from the mixer, the level being automatically limited whenever either of the three speak.

Here's an example of how this multiway talkback functions. The director would use the talkback as in the following example:

Director: Camera One recording now. (Tally on Cam 1 lights as Cam 1 Button is pressed on mixer programme output).
Director: Camera Two zoom in and move a bit to the left. (Cam 1 still on air).
Director: Camera Two recording. (Tally on Cam 2 goes on, tally on. Cam 1 goes out as Cam 2 button is pressed).
Director: Camera One pull back.
Camera One Operator: I can't. There's some big bloke in the way!

Inputs and Outputs

These are all on the rear of the MSX console and are divided into neat lined boxes.

Video
2 x 10-pin EIAJ connections for the two camera cables,
2 x BNC inputs for other camera or Time Base Correctors,
BNC output for black burst reference for other systems,
BNC output for Genlock Out.

Key + Effects
6-pin DIN External Effects Input,
3 x Inputs switchable between Mono
Caption Camera (5-pin DIN), Camera 1, or a video Typewriter (BNC),
Cermet rotary control for Key Level;
Reverse Key switchable between Highlight and Black Level.

Out
BNC Output for preview;
BNC Output for programme,
1/4" Jack Output for audio (6dB into 600Ω).

Audio In
2 x 1/4" Jack switchable between line/mic (input impedance 50KΩ for 600Ω or high impedance mic).

Recording
The output signal from the MXR console can be recorded onto any type of video recorder. If no editing is required and only one copy is needed, a VHS, Beta or Video 8 type domestic recorder is adequate. However, if you wish to make several copies, I would recommend recording onto a U-Matic format recorder.

Conclusions

I must admit that I found Unitron's inventiveness impressive. They've neatly succeeded in filling the gap between the limitations of domestic equipment and the cost of professional equipment. Their market up until now has been the small industrial unit, schools and colleges, and serious amateurs. Now they can add the semi-professional pop video maker to their lists. In the hands of a creative operator, the MSX system provides a most useful tool.

However, I would suggest that if buying the complete kit, you ask for some modifications to suit the particular needs of making demo pop videos. I doubt if you'll need the kit microphones, so you could leave those out. The MSX console comes with an enclosed pod which houses the two camera output monitors. The other two monitors sit on the top of this pod. If you don't intend to move the kit out of the studio this arrangement is fine, but it makes the unit very heavy. If you intend humping the studio around gigs and you're a weed like me, order the version which has an open tray for the bottom monitors. You can then easily move console and monitors separately without spinal injury.

The sliders are on the cheap side and the friction of the slide can make for uneven movement, particularly when using the double-linked wipe sliders. Unitron tell me that they can improve this situation by widening the slot in which the sliders move, thus reducing the friction. I expect that they're already doing this, but it might be an idea to mention the modification when ordering.

And Unitron have yet another goody up their sleeves: a special adaptation of a top range VHS Recorder which can enable you to edit between two recorders and the MSX console. I think a review of this little beastie could be in order at some future date as it sounds very useful.

The MSX system prices vary between £1,180 for a basic console to £6,770 for the full kit as reviewed.

Further details are available from: Unitron Products, (Contact Details).