Following up on their Esprite – and packing into it all the same technology – Robe has launched Forte, a more powerful spot/profile with an interchangeable 1,000 W white LED source that rivals the BMFL. We put it to the test in the studio at Impact Evénement and we also include, at the end of this article, a field report from our colleague Tristan Szylobryt, who used it on a video shoot.
This fixture is elegant. Slim and sleek, it weighs less than 40 kg (which is not bad for a mover in this category!) with a total height of 84 cm.
It’s a handsome, satin-finish anthracite colored baby. Two large lateral handles allow manipulation of the unit, the head of which can be locked on both the pan and tilt axes.
A large, 180 mm lens unleashes the beam! And what a nice beam it is! Forte delivers a beautiful, uniform white light of 6620 K with a flux that exceeds 34,000 lumens at 20°, and practically the same with a wide beam.
It almost reaches the performance level of the BMFL, thanks to its module of 121 LEDs of 10 W each, powered at 80% of their nominal power to ensure longevity.
The native CRI of the fixture is 69; it can be increased to 80 or 90 by using two filters on the color wheel (just so you know, an “HCR” version of the LED engine provides a native CRI of 94, with a 40% lower luminous flux).
With the unit on at full power, we measure the illuminance at the center every five minutes to plot the derating curve.
The light output stabilizes within five minutes with an attenuation of 7.5%, which testifies to the effective thermal management of the LED engine.
Tightest sharp-focus beam
At the minimum zoom setting that allows for sharp focus, 5.5°, we measure the center illuminance from a distance of 5 meters at 27,810 lux when cold (25,730 lx after derating), which corresponds to a luminous flux of 21,620 lumens (20,000 lm after derating). This is logically less than the BMFL which delivered 136,000 lux at 5 m with the hot spot of its 1700 W lamp, but the beam gains in homogeneity as shown by the ultra-flat luminous intensity curve.
At a 20° beam angle, the Forte matches the BMFL with 37,400 lumens when cold (34,600 lm after derating) versus the 36,130 lm of the BMFL.
The beam from the Forte is remarkably uniform, with less than a 30% difference in illuminance between the center and the sharp edge.
Widest sharp-focus beam
Forte emits almost same flux at 52° – the widest angle – as it does at 20°. We measure 36,750 lm cold (34,000 lm after derating), compared to 35,000 lm for the BMFL.
We appreciate the flat intensity curve of an ultra-uniform beam.
Forte features a Cyan/Magenta/Yellow color mixing system, supplemented by a linear CTO and two wheels with five colors each. The first wheel has very intense, saturated hues (red, green, blue, orange, congo).
The second color wheel includes a 4-color filter, a warm green, a lavender and the two filters that increase the CRI to 80 and to 90. The filters of the color wheels – large asymmetrical trapezoids – are very effective when combined in split colors, without altering the contours of the beam. Coupled with the gobos, this produces a really nice result, which already impressed me on the Esprite.
The colors of the CMY system are splendid and there is almost no perception of the entrance of the flags into the beam, regardless of the zoom or the position of the focus. As on the Esprite, the color module is integrated into the optical system that concentrates the flux of the sources. Technically, it is “walled” into the source module.
This allows us to obtain very uniform tones, as the filter flags are never even slightly in focus in the beam. The color mixing is exemplary even with rather complicated hues – those that generally reveal the defects. The CTO is a little pinkish; just right.
A DMX channel named “minus green” can virtually simulate the introduction of a filter that minimizes greenish colors when capturing video. It is an operation on the CMY system that adjusts the tones by removing a little cyan and yellow and/or by adding a little magenta to obtain the simulation of a minus-green filter.
The 12 glass gobos, arranged on two wheels, are all rotatable and indexable. The selection of the set is quite varied and the effects they produce are flexible enough in terms of graphic or aerial projection to satisfy all kinds of users (there is even the renowned embossed glass pattern!). Personally, I am kind of disappointed by the absence of a real solid cone and a bar, but I like the interrupted cone, which is very impressive when used facing the audience and which always has a nice effect, especially with mixtures of colors.
The animation wheel (with cleverly spaced striations that work beautifully) has the advantage of being able to turn in either direction, which is a big plus. I love it! There is an optional “hot-spot” filter that can replace a gobo to create a sort of hot spot. This filter is designed to equalize a field of light created by several Forte units overlapping each other, by preventing that the overlapped edges become more luminous than the centers of the beams.
Frosts and prisms
Forte features two frost filters: a light 1° frost and a more aggressive 5° diffusion. These are not combinable. The first one is progressive, the second one can be, too, but it requires setting the DMX channel of the frost to 50% in the memory before its insertion (technically, from 0 to 100%, the DMX channel of the frost goes like this: open / frost 1 progressively / open / frost 2 progressively). Robe can supply other frosts (0.5°, 10°, 20°, 30°…) as an option, which can be easily used to replace those supplied with the unit.
The two prisms – a circular 4-facet and a linear 4-facet – are both rotatable and can be combined to multiply their effect.
An interesting point: there is little compromise regarding focus and zoom when using the prisms and frosts, as they are mounted with their motors on the optical modules. The movement of the lenses has little impact on their possible deployment (except for in the very short range where they meet).
Focus / zoom / iris
The zoom has a very extensive range from 5.5° to 51°. This is at the upper end of what seems to be the general standard on this type of high-end fixture.
The focus allows you to focus the beam, and all the effects projected at any distance, but it will not go as far as to sharply focus the filters on the color wheels (the 4-color or split-colors) because they are so far from the focal point (this is the drawback in exchange for the super quality of the color mixing). The close spacing between the gobo wheels allows for some absolutely brilliant morphing effects.
There is one thing to be aware of, though. Forte needs to be in sharp focus at all times. If you defocus it a little, there is a slight drop in perceptible flux. This is a phenomenon that seems to be due to Robe’s choice of optics.
On the same subject, again a bit surprising, when you narrow the beam down to the limit, an adjustment of the focus (in addition to the single adjustment of the zoom) reduces the diameter of the beam even further. In other words, to get to the tightest sharply-focused beam angle of 5.5°, you have to use the zoom and then the focus, even if it seems to be perfectly in focus, and you gain 10° in “clamping capacity” of fixture’s zoom.
The dimmer has two response modes: Linear and Square Law. The Square Law mode, the curve of which we have plotted, allows for smooth and progressive fades. The electronics manage the sources perfectly. The strobe functions are just as effective and can reach very high frequencies.
Forte’s framing module is effective. The sharpness is essentially on two planes, but the other two planes are not far off. The compromise that we usually have on the sharpness of fully closing shutters seems to me to be better in this case than on some other models.
The speed of the deployment of the shutters is excellent, as is the precision of the repositioning. The entire framing module can be rotated 60° in either direction, giving a total of 120° of adjustment, which is enough to cover any desired orientation.
Movements of the head and general operation
Mechanically, the Forte is a very sophisticated unit. The movements of the yoke are perfect. The slow movements are, just like the fast ones, very fine, precise and smooth, while the maximum movement speed is satisfactory for a fixture of this size.
Although the movements are very quiet, the ventilation noise measured in “automatic” mode is perceptible and it will be preferable for users looking for more silence – for example in theaters or opera houses – to configure Forte in “Quiet” mode, at the cost of a small reduction in light output.
The fixture is quite conventional in its overall design. The injected plastic cowlings are very well made, with the usual 100% Robe craftsmanship. We love it. The uniqueness lies in the back of the head, with the LED module very accessible and easily removable. Only one type of screw (Phillips) is used for the whole fixture.
Disassembling the head
The two cowls of the head can be removed by means of two captive, 1/4-turn screws. They are secured by a small safety cable. The modules are easily removable.
Everything can be removed except the color module, for the reason explained above.
Six fans are responsible for cooling the source module, three that draw air in and three that extract it.
The LED source module can be easily removed via six Phillips-head screws. It is a massive assembly consisting mainly of a large heat sink and heat pipe, to which is mounted the LED circuit board.
On the side, a small card records the status information of the module. It is NFC-enabled (like a bank card in contactless mode), to retrieve all the data from the fixture using a smartphone.
The data it provides includes “adaptive” operating hours. This information takes into account the “theoretical” age of the components depending on their use, because an LED that has been used for an hour at full power will not be subjected to the same level of wear and tear as an LED that has been used at full power for three minutes and the rest of the time at 20%, for example… So, very smart!
Immediately downstream from the source module, there is the lens/color module assembly, which is integrated into the frame of the fixture.
It consists first of a lens composed of 121 micro-lenses for collimating the beams, positioned as closely as possible to the LEDs.
Next comes the progressive color mixing system (CMY+CTO), followed by another condensing lens and, finally, the two color wheels.
Accessing the CMY flags is complicated but, since they are not exposed to air flow and, consequently, not to dust, there is no risk of them getting dirty. This is always a plus. Service on the modules will be limited to eventual repairs, and therefore carried out in the shop.
The first removable module contains the gobos. In the conventional manner, the two gobo wheels proudly display their six cylinders with interchangeable gobos measuring 30.8 mm in diameter, held by the familiar spring clip. The animation wheel is also included here.
The next module houses the framing shutters and the iris. The shutters and their connecting arms are on one side of the rotating frame, while on the other side is the iris. Just before the output lens, the zoom and focus lens carriages roll on sealed ball bearings on their rails, rather than on simple parallel slides.
Their movement is smooth and fluid, with absolute straightness. It is a robust and reliable industrial-grade apparatus. The prisms and frosts are mounted on each carriage. The prisms are mounted on cylinders, with a remote motor allowing for their rotation in either direction, with transmission via a small, smooth belt.
The frost filters are mounted on small magnetic plates and are therefore easily interchangeable. On this module there is also a small sensor that analyses the light emitted by the fixture internally, for the purpose of standardizing the flux of a rig that combines new and older fixtures.
All of them will be tuned according to the weakest fixture. It’s easy: you just need to connect the fixtures on the same line and control this function through the dedicated DMX channel. This can be very useful if you need absolute consistency on a whole group of fixtures. You can also use this sensor to request an instant light intensity measurement via this DMX channel, at any time.
The yoke and the base of FORTE
The covers of the yoke arms can be removed by means of four captive Phillips-head screws. On one side, there is the tilt mechanism with its belt, the tensioner and the pulley, as well as the motor positioned flat in the central section of the yoke. By simply removing a small sheet metal plate, the tilt belt can be replaced very easily, if necessary. The tilt lock is also located on this side.
Interestingly, as on many Robe fixtures (though not everyone knows this), the screws in this lock are specifically designed to “break” in the event of a major impact to the head, in order to limit damage. If this were to happen, you would simply have to replace the screws. Okay, if a grand piano were to fall from the 10th floor onto the unit, it wouldn’t make much of a difference, but in some cases it could save the fixture from a major repair. Nice touch!
On the other side, in the center of the other arm, a circuit board controls the pan and tilt motors, the ventilation, and also provides the link between the base and the electronics located in the head. At the top, the small wiring harness from the base runs to the head through the center of the tilt axis.
At the bottom, the pan motor drives the rotation of the central axis via a belt. Access to this is more complex, requiring the disassembly of the bottom of the head. In the base we find the two power supplies of the fixture, which draws a maximum of 1,250 W. One of them provides 70% of the power needs of the LED engine, while the other one provides the remaining 30%, as well as the power for the electronics of the fixture.
The connection panel features a True1 socket for the power supply, XLR5 input and output – duplicated on XLR3 connectors – for DMX connection, and an RJ45 socket for the network connection. On the other side of the base, there is the color touchscreen display and its control keys (even though the screen is touchscreen, it’s still convenient and reassuring to have keys). A USB port is used to upload software updates to the fixture.
The menu is quite conventional, it is the famous “Robe Navigation System 2” from ROBE. The interface is bright and easy to read. You’ll find all the classic configuration functions, setup and implementation of DMX patches and network addresses, as well as plenty of options: dimmer curves, fan modes, calibration, LED power supply frequency settings, etc.
Underneath the base, there are the omega brackets to suspend the fixture. The Forte can be rigged in three different orientations. Either straight,at 90° in either direction, or at an angle of about 30 degrees. A central lug provides an attachment for a safety cable. We are disappointed that the omega brackets supplied with Forte do not allow the mounting point to be offset, but Robe offers this accessory as an option. This is already quite good.
Linked gear: The i-FORTE!
Forte is a product that is decidedly focused on the use of new technologies and connectivity of all kinds! You can interact with the unit via your iPhone or Android smartphone.
Just bring your phone close to the base, right in the middle of the left handle, to establish a wireless NFC connection with your fixtures using the “ROBE COM” application.
This system allows you to transfer data to the fixtures, prepare and transfer a patch, a configuration, etc. It will be particularly useful for preparing a whole kit of fixtures without taking them out of the flight cases, simply by “scanning” them one after the other in a few moments. Very practical!
The unit can be controlled via DMX using a single 54-channel mode, or via Art-Net, MA-Net, sACN… there is a wide range of options.
Forte is a real pleasure to use. It is a very attractive unit that has some strong assets to satisfy lighting designers of all kinds. Very powerful, it can reach the level of the BMFL, but with a low power consumption of 1250 W, compared to 2000 W. It has multiple advantages that will allow it to take a prominent place in the inventories of lighting companies.
In a market where technological progress is making every piece of equipment obsolete more and more quickly, Forte is obviously positioned among the units that can be considered as a safe bet in the long term. A very nice product.
What we like:
- The colors
- The nice beam
- The connectivity
What we didn’t like:
- The supplied omega brackets can’t be offset mounted
More information on the Robe website
The field test
For giving me a little space in this article, I’d like to thank Jocelyn, whose passionate writing is unmistakable. I’ll take the opportunity, in a few lines, to share my feedback on the Forte, which is certainly a future best-seller for Robe Lighting.
As always with Robe, their ergonomic logic allows you to start a project with complete peace of mind, without even testing the fixture! For this one-shot gig, the designer, Julien Ferreiro, and I were able to get a ready-to-use Cast-Software and GDTF library, so that we could prepare everything in advance on Wysiwyg and grandMA3.
As usual, Robe’s website allowed us to analyze all the characteristics of the fixture and to download exhaustive documentation.
In virtual implementation, the fixture seems to inherit elements from both the BMFL and the Esprite; when pre-encoded, all the attributes fall naturally under my fingers.
In real life, for those familiar with the Robe range, the Forte can be configured and installed in a flash. So sure, it weighs what it weighs, but it’s well balanced and with the single flight cases with multiple handles, there are no worries – as long as you’re working with two people.
Since it wields the abundant power of the BMFL – without being too overbearing because the beam is very uniform – and with a smooth dimmer, a wide zoom range and a large output lens, I used my four Forte units as four principal directions of light, structuring the rest of the rig around them. While it does deliver powerful and beautiful light, the uniformity of the beam takes away a little of its bite, and it’s not as incisive as a tight-beam MegaPointe, but that’s obviously not its intended purpose.
After using the Esprite, I found continuity with the two rotating gobo wheels, using the first one to decorate my stage, and the second one (which I used less) for geometrical beams in the haze. I also found all the colorimetry improvements, with a deep CTO, the two CRI filters (rather pink to the eye, and quite draining on the flux), as well as a channel dedicated to minus/plus green.
Definitely a plus for this video shoot. The CMY mixing offers precise colors, rich in nuances, which I mostly used in cool or pinkish tones.
As for the effects – which I didn’t abuse much, for once – I found two prisms, one linear and one radial, which I would have preferred more open, personally. The frosts are very smooth, as well as the focusing, a real work of art. The animation wheel and the strobes are also efficient, although they were not used much this time, because the context of the concert did not require them much.
Between the setup, the rehearsals and the recording, the day was decidedly short for testing everything. I recognize that I had to work very quickly to finalize my scenes, and in retrospect I applaud the immense quality of the Forte: its power, combining balance and precision, which for some may lack imagination, but it proves to be frighteningly efficient and easy to use.
I would like to take this opportunity to give a warm mention to Vincent Bouquet and Franck Veber from Robe Lighting France, for their support and availability on this project. I can’t wait for the festivals to start again, so that this new flagship of the Czech company can shine!