The brilliant spotlight manufacturer Robert Juliat presents Arthur, an 800 watt LED followspot, which performs neck and neck with its 2500 W HMI-lamp counterpart, Aramis. Yes, ladies and gentlemen, I did say the equivalent light output of a 2500 HMI… Very few people would have believed this 10 years ago. Well, here we are…
In keeping with its established tradition, the French manufacturer couldn’t help but design an extremely attractive and impressive spotlight, the exterior of which just exudes quality…
You can recognize it as a Robert Juliat followspot, like a cannon ready to fire, 1.66 m long, equipped with controls and a bar that serves as a “handrail” for the operator to control the 69 kg unit. We are talking about a spot that consumes 800 watts and therefore less than 5 amps on a 230 V single-phase line (no more P17 32 A and the big dedicated cables!), and which only draws power when it is being used!
This beauty features a smart flight case
One of the small sides of the flight case is equipped with a hatch that allows you to slide out the GT 4000 stand. You can take it out before the spotlight, and put it away after having put the spot back in the case. No more of those maneuvers that involved putting the spotlight on the ground before grabbing the stand and deploying it… It’s just very practical. The spot is stored flat in its flight case, with the right arm of the yoke perfectly accessible.
Arthur in its flight case.
Also, this flight case is 60 cm wide, very practical when loading a truck. It is equipped with runners on one of the small sides that allow you to tip it without fear of damage, and handles on the bottom to get a hold on it from any position, even when it is stuck at the bottom of a stack of cases.
A small internal compartment also allows you to store some accessories (but obviously not the once-obligatory spare lamp!) and other power cables. In short, we really appreciate it! This flight case is really cool all around.
The hatch for the GT4000 stand in the flight case.
Arthur comes with the famous GT4000 stand, made by Robert Juliat. It was improved a short time ago, in particular the extension stops, which now offer a more secure and direct locking in relation to the hinge.
It is also possible to order it with an optional ball-bearing gimbal (especially useful for very heavy lights like Lancelot), for ultra-smooth movement.
The rear panel with the connectors.
On the back of the spotlight is the connection panel, with the True 1 socket for the internal power supply and an output to feed power to other units (up to two more) or accessories on the same line.
There are also XLR5 input/output connections for DMX, two RJ45 ports for networking (there is an internal switch), and two USB ports for software updates. An LED marked “Wireless” also suggests a future possibility to integrate a wireless data module.
Also on the rear, we find the forked bracket that holds the handrail, with two large holes to serve as lugs for large safety cables. One can easily install one or two large shackles or other rigging.
Under the rear of the unit, two hanging straps are used to secure the power and data cables so that they do not dangle in the air behind the spotlight.
On the operator’s side, there is the display with the associated keys for navigating through the menu, there are the two lens control handles (zoom and focus), the “roller” that controls the dimmer, the two levers for the auxiliary filters, and the iris control located just behind the yoke.
On the inside
A look at the inside of the rear section.
The top of the housing can be opened by means of a dozen BTR screws, giving us a view of all the elements of the rear section.
Several modules are positioned on vertical rails, like slots, which are plugged directly into large connectors secured by two screws.
At the bottom of the spotlight are three “cassette” modules: the power supply, drivers and control electronics. The LED source is also housed in a cassette that allows us to see its large condenser output lens. Eight fans and a heat sink with a heat pipe provide cooling.
Then comes the 72 mm fully-closing iris module, the same one found on many Robert Juliat classics, including the Korigan. The iris is controlled by the well known rotating handle.
The source module with its ventilation and its output lens.
The light passes through the two classic zoom and focus lenses. The two sliding controls for these, on the side, provide a linear and perfectly smooth motion and they can be locked by tightening the dedicated knobs. You can adjust the beam from 5.5° to 15°.
Between these two sets of lenses are the slot for the gobo holder, and two auxiliary filters: a frost and a 1/2-CTO in dichroic glass. The latter of these is optional and made by Rosco.
The auxiliary dichroic filters: frost and 1/2-CTO.
The two lenses and the gobo holder.
The “boomerang” color magazine.
To obtain a soft edge, it is better to use the frost than to defocus, which can cause a slight warping of the edges, spoiling its round shape.
The two auxiliary filters are controlled on the side of the spotlight using two dedicated and labeled handles.
For color changes, Arthur is equipped with a standard “boomerang” gel magazine for six gelatin filters, which can be swung up and in from under the housing.
As an option, there is a color changer with lateral handles that allows the overlapping of filters, whereas the standard “boomerang” system ejects a filter as soon as another one is inserted.
On the menu this evening…
While it can be used in the traditional way, like any other followspot, Arthur offers advanced options for a more precise and future-oriented operation than most models on the market. The menu provides complete diagnostics of the unit: the status of the source, temperature, operating time, but also the general status of the fixture, ventilation speed, electrical and electronic parameters, because this spot is equipped with sensors for complete monitoring and maintenance.
The menu display and control keys.
In addition to the conventional DMX address settings, there are RDM and network parameters. Robert Juliat has put a lot of work into the control of its fixtures, particularly the RDM, which provides reliable and practical functionality.
Arthur (like all of the latest generation of Robert Juliat lights) can be controlled and parameterized remotely thanks to the RDM via the DMX cable. The quality of your libraries and your consoles will do the rest.
In the settings, you have access to the configuration of your followspot as a “local tool” so that it meets the needs of the operator: you can set the brightness of the display, whether the screen is automatically turned off after a few seconds, you can set the default condition of the spotlight in the case of DMX signal loss or upon startup (you can choose to keep the last settings, go to blackout, or revert to another programming).
You can, of course, configure the response of the dimmer control (the direction of rotation of the roller control to raise and lower the intensity), you can calibrate it, you can select the dimming curve (linear or square) as well as its response time.
A plot of the dimming curve in Square mode from 0 to 10%.
A plot of the dimming curve in Square mode from 0 to 100%.
Arthur’s output can also be limited by selecting a maximum intensity level. Imagine, for example, a room smaller than the one in which your show is usually staged. Simply set the maximum output level to 50% or 75%, and the spot will proportionally adapt the power to this new maximum value. This is interesting because the operator or console settings do not need to be changed. The frequency of the power supply to the LEDs can be adjusted to avoid flickering in video shots.
This spotlight is already very quiet in normal mode, but it offers two additional DMX-controlled cooling modes, one of which is “silent” (35 dB). This may not sound very important for a rock or pop concert, but it is really appreciated in an opera house or a theater. Obviously, you will have to accept some compromise in terms of luminous output, even if it is quite minimal.
When the unit is powered on (via the switch), the spotlight is ready to go after a “reset” of about ten seconds. The light that it emits is a cold white that we measured at 5425 K, with a CRI of 90 enough to satisfy even the most demanding requirements. It’s neat, sharp, precise. There’s no centering to do, no fiddling around, it is ultra-clean.
A plot of the derating curve.
We start by plotting the derating curve. This means that, at full power, we measure the attenuation of the fixture’s illuminance as a function of the warm-up time. Arthur’s light stabilizes in five minutes with a slight attenuation of 8%. Now we can begin the photometric measurements, this time at a distance of 10 m from our calibrated target, which is possible in the vast showroom at Impact Evénement.
Tightest sharp-focus beam
At a distance of 10 m from the target, the beam has a diameter of 1.02 m, which gives us a divergence angle of 5.85°. The illuminance at the center before derating is 28,300 lux (30,800 lx before derating) and from that we calculate a flux of 17,800 lumens (19,500 lm cold).
Reduced to 5 m, the distance we usually use for our tests, the illuminance values become 113,200 lux (123,200 lx cold). The flux values remain constant.
Widest sharp-focus beam
Here we measure a diameter of 2.4 m, which corresponds to an angle of 13.7°. The illuminance at the center is 5760 lux after derating (6270 lx when cold) and the flux reaches 25,170 lm (27,400 when cold). These measurements confirm the exceptional power of this spotlight, and the exemplary uniformity of its beam.
We can perfectly understand how nice and refreshing it will be to get rid of the endless problems of aging lamps, lamps with varying color values… in short, there are only advantages. A little bonus is that it can provide a strobe effect that can be controlled via DMX or the network.
As for the handling of the fixture, we asked Julien Tremblay – a followspot operator who is accustomed to working with these powerful spotlights on large national tours and events of all sizes – to give us his impressions of Arthur.
Julien Tremblay : “I regularly use 2.5 kW spots of different generations on tour. The size of Arthur reminds me of the Aramis and all the controls are very similar to the ones we are familiar with on the other models of this brand. For the operator, using it is therefore completely straightforward, comparable to a classic lamp-based model, and even simpler, since there is no ballast to manage.
“Of course there is the interface and its many functions, but it doesn’t interfere in any way with normal operation. You plug it in, turn up the dimmer and it shines! The advanced management functions will probably be a big plus for more advanced uses and will provide benefits in many situations. Arthur offers significant incentives for replacing aging lamp-based models.”
Julien Tremblay using Arthur.
Usage, DMX and network
Arthur can be controlled using six different modes (using 1, 2, 5, 6, 6, and 8 channels), from the simplest (dimmer) to the most advanced (dimmer / dimmer fine / master / master fine / strobe / strobe rate / dimmer response time / control mode).
The parameters received from a lighting console can be integrated into the programming of a show, offering the possibility of a more or less shared control between the spot operator and the lighting console. The first obvious example: perfectly controlled blackouts and fade-outs on the entire lighting kit, including followspots…
This can also be used for instant control of the intensity by the director of photography without having to give instructions over the intercom and without disturbing the operator who is busy with following the talent. These priorities are guaranteed by the separate management of the “Master” and “Dimmer” channels.
It can be a joint effort, where the console operator and the spot operator share control in perfect coordination, to the point where the console operator has total control over the light, leaving only the work of moving the spotlight and the optical adjustments to the spot operator. It is also possible in the fixture’s menu to disable the operation of the manual dimmer control, to avoid any unfortunate initiatives…
In case of a console crash or an unforeseen problem, the operator can take control by selecting a function in the menu or, in an emergency, by simply disconnecting the DMX plug. The fixture will then signal that it is no longer receiving DMX, and the operator can immediately take control simply by pressing ENTER.
For dimming control, the spotlight responds mainly on two channels: a master, and a dimmer. The master is an absolute control of the maximum light output of the fixture. It is independent of the input from the operator, as long as it is lower than the maximum value defined by the master channel. It should be noted that the response of the dimmer is then proportional over its entire travel, within the range of 0 to 100% of the value set by the master.
It is also possible to program from the console the response modes of the dimmer controlled by the operator, with fade times tailored to very fine and very gradual dimming (up to four seconds of fade). We can then create very slow fade-outs and fade-ins without the stress of making smooth finger movements, or even simply match the fade of the Arthur to the inertia of the halogen spotlights. On the other hand, it allows for more rapid effects for immediate blackouts.
Obviously, Arthur can also integrate with the Spot-Me tracking system (voir l’article de SoundLightUp sur le Spot-me).
The Telrad viewfinder and its magnetic support and base.
Robert Juliat offers a nice Telrad viewfinder with a magnetic mount and two articulations to adapt to any model of followspot, even rounded ones.
It also has aluminum clips for Merlin, and a riser with a small sling, in short, the whole package!
Once again, Robert Juliat demonstrates their unparalleled expertise in followspots, with a high-powered LED unit. If we add the numerous advantages of this modern technology, in terms of operational efficiency, capabilities, versatility of use and ease of maintenance of this modular design, we can already predict that Arthur will quickly take its place in the inventories of most lighting vendors and in theaters.
And, to make things even sweeter, its favorable price positioning (a little less expensive than the lamp-based equivalent!) will make it possible to contemplate this investment rationally. It’s a real gem!