Posted 28 November 2009 - 08:57 AM
Posted 28 November 2009 - 08:39 PM
I have looked HARD at LED and i just can't seem to get past the cost at this time. So that brings me back to Kino. I have convinced myself that buying a Diva 400 is a good move because of the flexibility of the light. The 4' 4 bank is also in my sights for a number of reasons including the full body beam spread.
do a search of the boards. You'll find a whole of detail and pros and cons of the Diva and the other flo fixtures quite recently.
Posted 29 November 2009 - 08:18 PM
I'm want to upgrade/ round out my lighting package to include some Kino .... I have convinced myself that buying a Diva 400 is a good move because of the flexibility of the light. The 4' 4 bank is also in my sights for a number of reasons including the full body beam spread. There are some new products from Kino such as the Bar Fly 400 and the Vista single that also interest me. ... I live in Indiana and do not have the option to demo these at a local dealer. So i must relay on what i can read on the internet and great forums like this one for many of my purchasing decisions..... Just so you know, most of my lighting is on large corporate video projects as well as regional TV spots. Best Regards.... David
Since you do spot work and large corporate projects, you would probably be better served by a Kino Flo Parabeam 400 rather than either the Diva, BarFly, Vistabeam, or 4' 4 Bank T12 Kino fixture which are more suited to documentary production. Before I give you my reasons, in the interest of full disclosure, I should first say that in addition to being a gaffer, I own and operate a rental house that rents and sells the equipment I am abour to recommend. If what I am about to say sounds like I’m hyping the Kino Flo product line it is not because we rent and sell them exclusively. We are dealers and rental agents for just about all the major brands. As a professional Gaffer of a lot of tight budgeted historical documentaries for PBS’ American Experience and The History Channel (see my “credit-entials” on Imbd), I think it is worth noting that the Kino Flo Parabeam fixtures are a viable alternative to HMIs when used with the new inverter generators because they offer low budget independent filmmakers a more affordable alternative to HMI lighting.
My recommendations are also based upon extensive research I have done on the use of portable gas generators in motion picture production. For this research, I ran a series of tests in order to analyze the interaction of conventional AVR generators (a Honda EX5500 with Crystal Governor), as well as inverter generators (a Honda EU6500is), with the prevalent light sources available today. I have compiled the results of my tests in an article for my company newsletter and it is available on our website.
What distinguishes the Parabeam fixtures from the Diva fixtures (and all other fluorescent lights for that matter) is their throw, power efficiency, and the innovative accessories Kino Flo makes available for the fixtures 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 fluorescent light will serve you best, depends on how you plan to use it. By the description of what you shoot, it sounds like you would be best served by the ParaBeam 400 fixtures because they have computer aided designed (CAD) parabolic reflectors that focus the light output where it is needed most for lighting dramatic scenes - at a medium distance – making it a better key source for spot work than the Diva 400, Bar Fly 400, or 4’ 4 Bank Kinos. If you compare the photometric tables of the Parabeam 400 and the Diva 400 (which uses the same four lamps), 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. In fact a Parabeam 400 generates as much light at 16’ as the 4’ 8-Tube Kino Flathead 80 fixture, yet uses less than a quarter of the power – making it an ideal light to operate on a portable generator.
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. Another 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 Flathead harder or make it throw further.
Not only do the Parabeam fixtures have more throw, but they are also easily controlled – an essential requirement in a Key source. Parabeam fixtures are controlled by interchanging Kino Flos’ innovative Honeycomb Louvers. Louvers are available in 90, 60 and 45 degrees. Swapping louvers provides beam control similar to that of swapping lenses on an HMI Par. These features enhance the production capabilities of the Parabeam fixtures and make them suitable to serve as a key or backlight source where conventional fluorescent movie light fixtures will spill all over the set. These features make the Parabeam fixtures the best candidate of all fluorescent lights to replace incandescent soft lights in their roll as dramatic key sources. And, the power you save by not using tungsten instruments for keys and backlights, enables you to power more lights on the generator than you could otherwise.
Another, advantage to the Parabeam 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 Parabeam 400s for the same power as a 4’ – 4 Bank Kino. Kino Flo is able to obtain such efficiency in their Parabeam 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 Parabeam 400 fixtures are especially well suited for use on small portable generators which is an important consideration for spot work.
All Kino Flo 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 below 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. Center: Scope time base adjusted to bring elongated waveform back on screen. 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.
Wide 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).
Two Shot reverse keyed by a pair of Parabeam 400s
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 Parabeam 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 Kino Flo Parabeam ballasts interact with inverter generators, not to mention their versatility (they can operate both 5500K & 3200K lamps) and their efficiency (they consume 1/10 the power of comparable incandescent soft lights), Kino Flo Parabeam lights would appear to be the better source for the type of filming you do.
Guy Holt, Gaffer, ScreenLight & Grip, Boston
Posted 30 November 2009 - 12:17 AM
Thanks again, PS -your web site is great ! David
Posted 30 November 2009 - 10:44 AM
OK Let me put this out there. If you had to own 3 Kino flo lights [ exclude a 12 volt kit since i own one] what would you own. Again corporate work, interviews, regional spots, small Indy features. #1Parabeam400 #2____? #3______?
Personally, I would choose the following #1 Parabeam 400 #2 Parabeam 400 #3 4'- 4 Bank. As a rental house owner operator I would choose the same. You can always diffuse a Parabeam 400 to get the equivalent of a Diva 400 and BarFly 400. But you will never get the punch or control out a Diva 400 or BarFly 400 that you get out of a Parabeam 400. The 4'- 4 Bank is still a very popular light because of it's flexibility.
- Guy Holt, ScreenLight & Grip
Posted 06 December 2009 - 01:29 PM