Kino 4 bank vs Diva

[Phil Parmet]

Divas are great light and small, but yeah watch out for the magenta shift when you dim them down. I've found the color shift so serious that I rarely use the dimmer function.

 

[Eileen Ryan]

One of the pluses of the diva was the honeycomb grids. I wanted to be able to control the light too. But I found lighttools.com and it's exactly what I wanted, albeit a tad expensive.

If you want to be able to control the light, you should definitely consider the Parabeam Fixtures. Kino Flo makes available for the ParaBeam 400 and 200 fixtures a number of innovative accessories that enhance their production capabilities. Accessories include barndoors, a gel frame, a diffusion panel, and Honeycomb Louvers. Honeycomb Louvers are available in 90, 60 and 45 degrees. Swapping louvers provides beam control similar to that of swapping lenses on an HMI Par. The Diffusion Panel, on the other hand, slightly softens the beam structure in the open face mode.

In the end, which light will serve you better, depends on how you plan to use it. The ParaBeam 400 fixtures, have computer aided designed (CAD) parabolic reflectors that focus the light output at about 16 feet (5 meters). If you compare the photometric tables of the Parabeam 400 and the Diva 400, you will notice that at 16’ the Parabeam 400 puts out almost three times the light level (28FC) than the Diva 400 (10FC) even though they both use the same tubes. Where the Parabeam 400 focuses the light output of the lamps where it is needed most for lighting dramatic scenes - at a medium distance – the Parabeam makes for a better key source for HD Digital Cinema than the Diva 400.

The flip side, is that the Parabeam 400 will be harder and less flattering to your talent as a key source in an interview set up. Given its large size, a 4’ – 4 Bank Kino makes for a more flattering key source in interview set ups than the Parabeam 400.

But, where a 4’ – 4 Bank Kino generates a very broad soft light that tends to drop off rapidly they generally do not have the “throw” to serve as a key source in dramatic sets ups. In dramatic setups in close quarters the 4’ – 4 Bank Kino makes a very good fill source.

So, as you can see, it really depends on how you plan to use it. One advantage to the Parabeam 400 is that you can use the accessory diffusion panel or put diffusion on it to make it softer, where you can not make a 4’ – 4 Bank Kino harder or make it throw further.

Another, advantage to the Parabeam 400 is that it draws half the power (2 Amps) than a 4’ – 4 Bank Kino (4 Amps). While this two amp difference is not a major consideration when using house power, it can make a difference when your power is coming from a portable generator. Where power is limited, the less power a light uses, the more lights you can power from the generator. For example, I recently worked on an independent short, shot on the Red, where we used Parabeam 400s as our keys. Given the light sensitivity of the Red Camera, the more focused light of the Parabeam 400s was all that we needed for our keys even at a distance. The power we saved by not using tungsten instruments for our keys, enabled us to power more lights on the generator than we could otherwise. By using a step down transformer on a Honda EU6500is we were able to power a lighting package that consisted of a 2.5kw, 1200, & 800 HMI Pars, a couple of Parabeam 200s, and a Flat Head 80, in addition to the two Parabeam 400s. Again, given the light sensitivity of the Red Camera this was all the light we needed to light a large night exterior (go to www.screenlightandgrip.com/html/hdfilmstrip4lg.html for details on this production.)

Eileen Ryan, New England Gaffer

 

[DS Williams]

I agree that the Parabeam may be something to look into. It has 4x the through of the 4Banks. But, different tools for different jobs.

 

[Guy Bryan Holt]

Kino 4 Bank vs Diva 400

Kino 4 Bank vs Diva 400

I'm deciding between the two. Can anyone tell me their experience between the two?

An advantage to the Diva 400 is that it draws less than half of the power (2 Amps) than a 4’ – 4 Bank Kino (4.6 Amps). While this nearly 3 amp difference is not a major consideration when using house power, it can make a difference when your power is coming from a portable generator because you can use two Diva 400s for the same power as a 4’ – 4 Bank Kino. Kino Flo is able to obtain such efficiency in their Diva fixtures by incorporating Power Factor Correction circuitry into their ballasts. As it does in HMI ballasts, this advanced electronics contributes to a more economical use of power than Kino Flo’s conventional electronic ballasts and reduces the return of harmonic currents into the power stream. With a Power Factor Rating of over .9, the Diva 400 fixtures are especially well suited for use on small portable generators.

All fluorescent fixtures are a good choice for operation on small portable generators in the limited sense that they use a quarter of the power of a comparable tungsten soft light. However, the ballasts of the older style Kino Flo fixtures, like the 4’ – 4 bank Kinos, that use the T-12 tubes (the Single, Double, and 4 Bank Fixtures, the Wall-o-Lite, Flathead 80, and the Image 20, 40, & 80 fixtures) are not power factor corrected and return harmonic currents into the power stream. When used in quantity, as in studio chroma key productions, they can constitute a source of considerable harmonic noise in the power stream. For this reason, Kino Flo cautions users, on their website: “Kino Flo ballasts are generally not power factor corrected. They will draw double the current on the neutral from what is being drawn on the two hot legs. On large installations it may be necessary to double your neutral run so as not to exceed your cable capacity.”( FAQ “Why is the neutral drawing more than the hot leg” at http://www.kinoflo.com/FYI/FAQs.htm#2) For a detailed explanation for why harmonic currents cause unusually high neutral returns see my article on the use of portable generators in motion picture production available on our website.

When you plug a single 4’ - 4 Bank Kino into a wall outlet you need not be concerned about harmonic currents. As is the case with non-PFC HMI ballasts discussed elsewhere in this forum, the impedance of the electrical path from the power plant is so low, the distortion of the original voltage waveform so small (1-3%), and the plant capacity so large in comparison to the load of the one light, that the inherently noisy load of the 4’- 4 Bank Kino will not affect the voltage at the distribution bus.

Left: Grid Power w/ no load and a THD of less then 3%. Center: Conventional Generator w/ no load and a THD of 17-19%. Right: Inverter Generator w/ no load and a THD of 2.5%.​

It is, however, an all together different situation when plugging Kino Flo T-12 fixtures into conventional portable generators. As a comparison of the oscilloscope shots above and below indicate, the return of harmonic currents by conventional Kino Flo T-12 ballasts can generate voltage distortion in the power stream. Given the large sub-transient impedance of conventional portable generators, and the fact that the original supply voltage waveform of conventional generators is appreciably distorted (a THD of 17-19%) to begin with , you have a situation where the return of any harmonic currents by a non-PFC electronic ballast (HMI or Kino) will result in significant waveform distortion of the voltage in the distribution system.

Left: Grid Power w/ Kino Flo Wall-o-Lite. Center: Conventional AVR Power w/ Kino Flo Wall-o-Lite. Right: Inverter Power w/ Kino Flo Wall-o-Lite.​

Given the effect of just one 10–tube Kino Flo Wall-o-Lite with non-pfc electronic ballasts on a 5500W conventional generators, what would be the accumulative effect of a typical lighting load on a generator? To see, I ran a package consisting of two Arri 1200 HMI Par Pluses with standard Arri non-PFC electronic ballasts in addition to the Kino Flo Wall-o-Lite on the Honda EX5500 (a conventional generator). And, for the sake of comparison, I ran the same package but with power factor corrected electronic ballasts on our modified EU6500is (an inverter generator.) The difference between the resulting waveforms is startling. But, where I am out of space, I will have to pick up with the benefit of having power factor correction in the Diva Ballast.


Guy Holt, Gaffer, ScreenLight & Grip , Boston[/QUOTE]

 

[Guy Bryan Holt]

Given the effect of just one 10–tube Kino Flo Wall-o-Lite with non-pfc electronic ballasts on a 5500W conventional generators, what would be the accumulative effect of a typical lighting load on a generator?

Continued from above

To see, I ran a package consisting of two Arri 1200 HMI Par Pluses with standard Arri non-PFC electronic ballasts in addition to the Kino Flo Wall-o-Lite on the Honda EX5500 (a conventional generator). And, for the sake of comparison, I ran the same package but with power factor corrected electronic ballasts on our modified EU6500is (an inverter generator.) The difference between the resulting waveforms is startling.

The adverse effects of the severe harmonic noise exhibited below left, can take the form of overheating and failing equipment, efficiency losses, circuit breaker trips, excessive current on the neutral return, and instability of the generator’s voltage and frequency. For these reasons it has never been possible to reliably operate more than a couple of 1200W HMIs on a conventional 6500W portable gas generator. Harmonic noise of this magnitude can also damage HD digital cinema production equipment, create ground loops, and possibly create radio frequency (RF) interference. For a detailed explanation for why this is, see my article on the use of portable generators in motion picture production available on our website.

Left: Conventional generator power w/ pkg. of non-PFC Elec. HMI Ballasts & Kino Flo Wall-o-Lite. Right: Inverter generator power w/ Pkg. of PFC Elec. Ballasts & Kino Flo Parabeam 400.​

Why are harmonics suddenly an issue in motion picture electrical distribution systems? First, one must appreciate that the power generation and electrical distribution systems developed for motion picture production were never designed to deal with an abundance of non-linear loads like electronic HMI and Kino Flo ballasts. It’s a problem that has only recently begun because of the increasing use of these types of non-linear lighting loads. The problem is being further compounded by the increasing prevalence on set of sophisticated electronic production equipment like computers, hard drives and HD monitors which are themselves sources of harmonic distortion. The increasing use of these microprocessor-based equipment in production has created an unprecedented demand for clean, reliable power on set at a time when the prevailing light sources are dumping more and more noise into the power stream.?

It is worth noting in the oscilloscope shots above that the distortion of the voltage waveform is considerably less in the case of the inverter Honda EU6500is generator (far right) than that of the conventional Honda EX5500 generator (left.) The reason for this is that, as discussed at length in my article, the original waveform of the power generated by the EU6500is (an inverter generator) has less harmonic distortion at the outset than that originally generated by a EX5500 (conventional generator.) For this reason, when your lighting package consists predominantly of non-linear light sources, like HMI and Fluorescent lights, it is important to have power factor correction (PFC) circuitry in the ballasts (HMI & Kino) and operate them on inverter generators like our modified Honda EU6500is. The combination of improved power factor and the nearly pure power waveform of inverter generators makes it possible to power larger lights, or more smaller lights, than has been possible before on a small portable gas generator.

Two Shot of Night exterior scene lit with our HD P&P Pkg​

For example, the substantial reduction in line noise that results from using power factor corrected Kino and HMI ballasts on the nearly pure power waveform of an inverter generator creates a new math when it comes to calculating the load you can put on a generator. In the past we had to de-rate portable gas generators because of the inherent short comings of conventional generators with AVR and Frequency governing systems when dealing with the harmonic noise of non-PFC electronic ballasts. The harmonic distortion created by non-PFC ballasts reacting poorly with the distorted power waveform of conventional AVR generators (as evident in the oscilloscope shots above) limited the number HMIs and Kinos you could power on a portable generator to 60% of their rated capacity (4200Watts on a 6500W Generator).

But now, that inverter generators have virtually no inherent harmonic distortion or sub-transient impedance and power factor correction (PFC) is available in both small HMI and Kino Flo Diva ballasts, this conventional wisdom regarding portable gas generators no longer holds true. Where before you could not operate more than a couple 1200W HMIs with non-PFC ballasts on a conventional generator because of the consequent harmonic distortion, now according to the new math of low line noise, you can load an inverter generator to capacity. And if the generator is our modified EU6500is inverter generator, you will be able to run a continuous load of up to 7500W as long as your HMI and Kino ballasts are Power Factor Corrected.

The PFC 2.5 & 1.2 HMI Pars, PFC 800w Joker HMI, Kino Flo Flat Head 80, 2 ParaBeam 400s, and a ParaBeam 200 of our HD P&P Pkg. powered by our modified Honda EU6500is through our 60A Full Power Transformer/Distro​

According to this new math, when you add up the incremental savings in power to be gained by using only PFC ballasts, and combine it with the pure waveform of inverter generators, you can run more lights on a portable gas generator than has been possible before. For example, the 7500W capacity of our modified Honda EU6500is Inverter Generator powered a lighting package for a recent Red shoot (see production stills above and below) that consisted of a PFC 2.5kw HMI Par, PFC 1200, & 800 HMI Pars, a couple of Kino Flo ParaBeam 400s, a couple of ParaBeam 200s, and a Flat Head 80. Given the light sensitivity of HD cameras, this is all the light needed to light even a large night exterior. (For more details on how this is accomplished I suggest you read my newsletter article on the use of portable generators in motion picture production. The article is available on our website.

A Distro System consisting of a 60A Full Power Transformer/Distro, 2-60A GPC (Bates) Splitters, 2-60A Woodhead Box distributes power from a modified Honda EU6500is. Even though the generator is 100' away to reduce noise, plug-in points remain conveniently close to set.​

Given how well their ballasts interact with inverter generators, Kino Flo Diva lights would appear to be the better than 4' - 4 Bank Fixtures for the production of narrative HD Cinema, commercial spot work, or any type of production that is likely use a portable generator.


Guy Holt, Gaffer, ScreenLight & Grip , Boston