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Film School Dumping Kinos for LEDs


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How do they compare for size, weight, and noise?

 

As you can see by the pictures below of various 1200W ballasts, the Arri compact mag ballast is pretty compact but nowhere nears as small and lightweight as the two electronic ballasts. Mag ballasts also have a tendency to hum so they are best located outside the room in which you are shooting.

 

waveform_test_setup_comp.jpg

 

Left: Honda EU6500is (L) Honda EX5500 ® Center: Test Set-Up w/60A Full Power Transformer. Right: P2L PFC 1200W Elec. Ballast (L), Arri Non-PFC 1200W Elec. Ballast ©, Arri 1200W Magnetic Ballast ®

 

As you can see by the picture of the generators on the left, the Honda EU6500is is considerably smaller and lighter than the old Honda EX5500. I am going out on location for a couple of days, so I won't be able to respond to any more questions until Monday. As much as I love chatting with you guys, I gotta do that work thing to pay the bills.

 

- Guy Holt, Gaffer, ScreenLight & Grip, Lighting and Grip Rental and Sales in Boston.

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I agree a hundred percent. We are no longer in our parent’s linear world. The power generation and electrical distribution systems developed then were much simpler. But, unfortunately they were not designed to deal with the abundance of non-linear loads like electronic HMI and Kino Flo ballasts that make up lighting packages today. It’s a problem that has only recently begun because of the increasing use of non-linear lighting loads. The problem is being further compounded by the increasing prevalence on set of sophisticated electronic production equipment like HD cameras, computers, hard drives, and monitors which are not only sensitive to harmonic distortion, but are themselves sources of harmonic distortion. 



 

For instance, the self-excited AVR systems of conventional generators were not designed to operate with leading power factor loads. In AVR systems, the AC voltage generated is controlled by DC excitation of the electro-magnets of the generator's Rotor. The amount of DC excitation required is a function of generator load; or, put another way, the excitation required to maintain constant voltage increases with load. The type of load also affects the amount of excitation required. Lagging power factor loads (magnetic ballasts) require more excitation than a unity power factor load (Quartz Lights.) Leading power factor loads (electronic ballasts) require less excitation than unity power factor loads. 

Rudimentary AVR systems like those in portable generators are ill equipped to deal with leading power factor loads like electronic ballasts because the harmonic currents they generate create flux in the armature coils of the Stator that reacts additively with the Exciter flux in the field poles of the Rotor to increase saturation and produce a higher terminal voltage than called for a given load. Consequently, the AVR system responds erroneously to control voltage by reducing excitation. The end result is that the regulator goes to its minimum excitation capability while the additive excitation of the armature flux from the leading power factor causes the terminal voltage to continue to rise and not be controlled by the voltage regulator. 



 

Erroneous regulation of voltage is just one example of the more severe effect that leading power factor loads have on conventional AVR generators than do lagging power factor loads. In researching my newsletter article I compared the characteristic voltage waveform distortion created by different lighting loads on different generators, and found that leading power factor loads also have a more severe effect on other production equipment operating on the same power.

Use this link for my newsletter article that explains the electrical engineering principles behind these issues and how to resolve them.

 

 

- Guy Holt, Gaffer, ScreenLight & Grip, Lighting and Grip Rental and Sales in Boston

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OK, maybe one way to make all this power factor complexity go away is to go back to DC -- solar panels and batteries, zero Hertz. Sure, we'd have do get along without transformers. But with everything small and distributed instead of big and centralized, would that be so bad?

 

 

 

 

-- J.S.

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I just hope they plan to get enough LED's to create large sources, by modifying them to create large 2' x 4' or 4 x 4' litepanels. Otherwise you're stuck with smaller spotty LED's that won't give you much coverage for a scene's wide shots.

 

If they're set on LED's, I'd make this point and make sure they replace the Kino's with light sources of similar source SIZE :)

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I just hope they plan to get enough LED's to create large sources, by modifying them to create large 2' x 4' or 4 x 4' litepanels. Otherwise you're stuck with smaller spotty LED's that won't give you much coverage for a scene's wide shots. If they're set on LED's, I'd make this point ...

 

And the point that a rig like the one Phil pictures above will draw nearly twice the load as you would think (10 Amps verses 5.33 Amps) because of their poor Power Factor and that their Leading Power Factor will have an adverse effect on conventional AVR generators and other equipment operating on the same power for the reasons discussed above.

 

- Guy Holt, Gaffer, ScreenLight & Grip, Lighting and Grip Rental & Sales in Boston

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I don't understand that at all. A single 1x1 litepanel is not a low cost piece of hardware, despite its intrinsic simplicity. You'd have thought they'd at least have shipped them with decent power supplies. I'm appalled, if they really do have poor power factor.

 

Although - I wouldn't be surprised to hear they'd draw about 10A from a 110V line, on the basis that it's 720W (16x45W) on paper.

 

P

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I wouldn't be surprised to hear they'd draw about 10A from a 110V line, on the basis that it's 720W (16x45W) on paper.

 

Ignoring its’ Power Factor, a more accurate paper calculation for the 16 fixture Litepanel bank Phil refers to above would be 640W (16 x 40W) since according to the manufacturer, the AC-to-DC power supply that Litepanel uses for their 1x1 fixtures generates 24V DC and according to the Litepanel website the load of a 1x1 is 40W at 24V (its 45 Watts at 12V.) With a PF of .54 its’ actual load is 1185 Watts which is how I came up with the draw of 10A at 120V (it would be closer to 11 Amps at 110V.)

 

I don't understand that at all. A single 1x1 litepanel is not a low cost piece of hardware, despite its intrinsic simplicity. You'd have thought they'd at least have shipped them with decent power supplies. I'm appalled, if they really do have poor power factor.

 

Again, I don’t know the exact manufacturing cost to incorporating PFC circuitry in LED AC-to-DC power supplies, but apparently it is enough of a cost consideration to lead Litepanels to not incorporate it into the AC power supplies they use for the Litepanel 1x1s.

 

LED_1x1_Power_Supply_alt.jpg

Litepanel 1x1s use the Cincom TR70A24 SMPSs Type AC-to-DC Converter

 

For the 1x1s they use the Cincom TR70A24 SMPSs Type AC-to-DC Converter (pictured above) which, to their credit, is by not means a cheap power supply. It boasts line regulation specifications of +/- 1%, load regulation of +/- 2%, and an efficiency of 84%. With specs like these you won’t see the flicker that you sometimes see in cheaper LED fixtures where the manufacturer doesn’t bother using a fully regulated DC output, but instead opts for poorly rectified AC.

 

LED_1by_Har_Distri.jpg

Distribution of harmonics generated by the power supply of the Litepanel 1x1 LED Fixtures. Note: predominance of the 3rd, 5th,

7th, and 9th harmonics that don't cancel on neutral returns.

 

However, the Cincom TR70A24 also has a Leading Power Factor of .54 and a Total Harmonic Distortion (THD) of 68.1% (see chart above.) As such, it generates a very distorted current that is significantly phase-shifted with respect to the sinusoidal voltage waveform (see oscilloscope graph below), and when used in quantity on a conventional portable generator, can have an adverse effect on its power quality (see oscilloscope shot below), similar to that of the CFL bulbs in the You-Tube video I mentioned earlier.

 

LED_Non_PFC_Waveforms.jpg

Voltage and Current waveforms generated by SMPS type AC-to-DC Converter used to drive AC LEDs.

 

Power Factors for the power supplies used in the Litepanel line of LED fixtures range from 0.54 (Litepanel 1x1s), to 0.85 (Litepanel Sola Fresnels) where Zylight’s IS3 Intelligent Studio LED Light has a PF of .98 (but it costs $2,580 verses $1549.00 for a 1x1 Litepanel.) So obviously, for some reason Litepanels has decided not to incorporate it into their power supplies for the fixtures they market in this country. Perhaps because it is an unnecessary additional expense since Power Factor Correction (PFC) is not mandated in this country, as it is in Europe for any electrical device that draws more than 75W, or simply they felt it was not an issue where the typical application of the units involves only one or two fixtures.

 

CFL_FlatTop_Waveform.jpg

The type of voltage waveform distortion that can be generated in conventional AVR generators by SMPS type AC-to-DC Converter used to drive AC LEDs.

 

However, as illustrated in the You-Tube video above, if used in quantity on a conventional portable generator, they can lead to the type of voltage waveform distortion in the oscilloscope shot above and so have an adverse effect on both the generator and other equipment operating on the same power (Use this link - http://www.screenlightandgrip.com/html/ema...generators.html - for a detailed description of the adverse effects that LEDs can have on portable generators.)

 

Guy Holt, Gaffer, ScreenLight & Grip, Lighting and Grip Rental & Sales in Boston

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Hi there. Allthough mentioned briefly in the other posts, most people here seem to be writing PHDs in lighting technology!? WHY HAS ALMOST NOBODY MENTIONED THE FACT THAT WE SEE WITH OUR EYES, NOT VOLTMETERS AMD CHROMA-METERS!! At the end of the day, what matters in CINEMATOGRAPHY is the look, feel, colour and texture of the results. Clearly Kino Flo and Compact fluorescence bulbs look much better on skin, and has the glow a light source should have when lighting faces. LEDs are so unnatural in appearance and colour spectrum, even the expensive ones that claim to have a high CRI rating, and 'true' colour, CLEARLY don't. Allthough my chroma-meter shows me the strange mix of colours present, Really you just need to look to see that. LED panels project light in almost a laser like way, and reflects off textured skin in the most un-appealing way possible. With old school 'fire based' tungsten lights and CFLs the light comes from a bright core and glows outwards from the center. This is the type of light our brains are hard wired to recognise (the sun), and it softens skin tones and roughness. GUYS JUST USE YOUR EYES, AND PUT THE CALCULATOR DOWN NOW!! Lighting is not just about projection and low power consumption, it is an artform that is vital to photography and painting alike. You don't get fine artists painting with fashionable organic sustainable toothpaste, because the results wouldn't be the same. Whatever anybody here states, you just have to look at the hardness and torch like direction of LEDs, and most importantly their UNRELIABLE DISCOLOURED, SYNTHETIC TEXTURE to know that LED panels are years away from esthetically replacing Kinos and CFL bulbs. The idea is good, and it will be progress one day, but please don't listen to loads of scientists and technicians, listen to the artists and audience who feel what they look at, they don't care what the device was made of, just the results it's displays. IF YOU DECIDE TO COMPLETELY LIGHT YOUR FILM WITH LEDS AND SHOOT IT IN UNFILTERED HD, GOOD LUCK, CAUSE ITS GOING TO LOOK TERRIBLE AND THE LEAD ACTRESS WILL HATE YOU FOREVER. YOUR CLOSE-UPS WILL LOOK LIKE A SKIN ANALYSIS SHOT, AND YOUR HARD SHADOWS WILL LOOK LIKE YOU NEVER LEARNT THE BASICS OF LIGHTING TO START WITH. YOU MAY THINK YOUR KIT IS COOL, BUT THATS NOT THE POINT OF CINEMATOGRAPHY. By the time you have added diff, warm gels, and filled in the hard nose shadows, you could have just used a globe or couple of 'normal' bounced lights anyway. LEDS ARE CURRENTLY IN THE EARLY STAGE THAT HARSH GREEN FLUORESCENCE WERE 15 YEARS AGO. NOW KINOS ARE SOO MUCH BETTER, SO WHY STEP BACKWARD AND USE INFERIOR LEDS, JUST BECAUSE ITS FASHIONABLE AND THE NEW GADGET TO HAVE ON SET. A good cinematographer with any pride, should use what looks the nicest on camera, and what flatters their talent. If that means working around practicle issues, well that's part if our job. Your school is trying to future proof their investment in kit, but will be making a large esthetic sacrafice in the process. What next, light it completely in post and ignore actual photography skills ?!?! Kinos are still lightweight, low power and fairly versatile, so why give you something less to work with and most importantly train/learn with? In this age of video the art of cinematography is being pushed aside for self-shooting, low budget, undiciplined, unplanned lazy shooting that is almost completely reliant on post production and software to make it look professional. If they give you just LEDs aswell, well you are held back from the start. IN RECENT YEARS I HAVE NOTICED THAT ALL THE NEW DoP SHOWREELS I SEE ARE GLOSSED UP WITH GRAPHICS AND POSTPRODUCTION, BUT THE ACTUAL RAW CONTENT, COMPOSITION, LIGHTING AND USE OF COLOUR IS ABSOLUTELY RUBBISH AND UNCONSIDERED. IF THE PLAYSTATION GENERATION IS TAUGHT FILM MAKING BY GADGETS AND PROGRAMMIMG, WELL THEN THIS INDUSTRY IS GOING DOWN, AND WE HAVE SEEN THE END OF PHOTOGRAPHY AS WE KNOW IT. USE YOUR EYES TO MAKE DECISIONS, NOT CALCULATIONS AND TRENDS!

Good luck with it, and fight the power! ;)

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.. most people here seem to be writing PHDs in lighting technology!? WHY HAS ALMOST NOBODY MENTIONED THE FACT THAT WE SEE WITH OUR EYES, NOT VOLTMETERS AMD CHROMA-METERS!! At the end of the day, what matters in CINEMATOGRAPHY is the look, feel, colour and texture of the results.

 

While I agree with you 100%, you also have to master your medium before you can create great works of art. You can be sure that the great painters through out history didn’t simply buy their pigments off the shelf of an artists supply store but instead mastered fundamental chemistry to create their own pigments. The same is true of our medium: if you don’t have a thorough understanding of your tools you will not be able to execute your artistic vision. For instance, if you are unaware, that the Leading Power Factor of lights that use Switch Mode Power Supplies (Electronic HMI, Fluorescent, & CFL ballasts, and LED power supplies) can cause them to use excessive amounts of power for the wattage of light they generate and to kick harmonics back into the power stream that can have a severe adverse effect on not only the generator, but also other electronic equipment operating on the same power, then you may never have the opportunity to create that great work of cinema because your HMIs wouldn’t hold their strike, your LEDs flickered, your Tungsten lights were excessively orange, your camera batteries wouldn’t charge, and your back up hard-drives locked up. For better or worse, cinematography is a technical medium. If you don’t master the technology, you will never have the control over the medium required to make great art.

 

- Guy Holt, Gaffer, ScreenLight & Grip, Lighting rental & sales in Boston

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Do you happen to know what wattages Arri are going to build for the L series?

 

Word from NAB is that the L-Series LED Fresnels being introduced by Arri this week are a line of three 200W heads. They consist of the L7-D, L7-T and L7-C. All share the same basic housing and the same 7" Fresnel lens, and all have output comparable in intensity to a conventional 1K Fresnel. They differ in terms of color temperature, with the D model outputting a daylight-equivalent 5600 K, the T model a tungsten-equivalent 3200 K, and the top-of-the-range C model offering total color control. All offer a CRI and CQS greater than 90 so skin tones, costumes and scenery will finally appear lifelike under LED light.

Arri_LSeries_PS.jpg

 

There are two alternative cooling systems: one passive and the other active. The passive cooling system was designed for broadcast studios. It incorporates no moving parts or fans and is therefore completely silent. The active cooling system was designed to provide a more compact and lightweight option for location work. It uses an extremely quiet (<20 dB) fan and weighs 10lbs less than the studio version.

ArriL7_Active_Cooling.jpg

 

The location fixture carries an IP54 rating for weather resistance which means that it is protected from falling rain and splashing water, and that the internal electronics, optics and LEDs are protected from dust, dirt and humidity – making it a very robust fixture that will stand up to the rigors of location production.

ArriL7_watertest.jpg

 

All the L7s feature Power Factor Correction with a near unity Power Factor of .91. Which means that the 200W fixtures will draw no more than 1.98A at 120V (220W) and cause virtually no Harmonic Distortion. Since it creates virtually no line noise, you will be able to power nine 200W L7s on the 20A circuit of a portable generator without a problem. And since the L7-T has an output comparable to a 1k Quartz Fresnel, and the L7-D has an output comparable to a 575W HMI Fresnel, the L7 series takes what you can do with a portable generator to a new level. For example, with the enhanced 7500W output of our modified Honda EU6500is, you will be able to operate a lighting package consisting of a 30 L7s. I think you would have to agree that is an incredible step-up in production capability.

ArriL7_upgrade.jpg

 

At a price around $2’500, the L7s are one of the more expensive LED fixtures out there. But, to assure that they are not quickly rendered obsolete by the rapid advances being made in LED chip efficiency, they are designed to be an expansible platform that can incorporate future developments in LED technology. Not only, do the heads allow for the incorporation of more efficient LED chips when they become available, but the light engine is also fully upgradeable, ensuring that the fixtures can take advantage of technology advances as they happen.
 To accommodate future control protocols (such as ANC), their firmware is also upgradeable through the USB port on the rear of each unit.
 They will also be compatible with planned future optic accessories that will expand the L-Series versatility. Able to incorporate future developments in LED technology, the expansible platform of the L7s ensures that they will have a long useable life and so will assure a return on investment in them. Given the rapid pace of LED Chip development, I can’t think of another LED fixture that won’t be obsolete in a year or two.

 

With the same clear and defined shadow rendering, excellent field homogeneity, and smooth continuous flood to spot focus of Arri's ST-1 1kw Quartz Fresnel, these first production models of the L-Series LED Fresnels may well be the first true LED Fresnel lights (use this link for more details.) For more detailed information on the Power Quality generated by LED power supplies and to see a demonstration video of the new Arri L-Series LED Fresnels, use this link to an article I wrote for our company newsletter on the use of portable generators in motion picture lighting. In it I cover some of the basic electrical engineering principles behind LED drivers, the harmonic distortion they can generate, and how it can adversely affect generators. The article and the demonstration video are available online at http://www.screenlightandgrip.com/html/emailnewsletter_generators.html.

 

Guy Holt, Gaffer, ScreenLight & Grip, Lightng & Grip Rental in Boston

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While I agree with you 100%, you also have to master your medium before you can create great works of art. You can be sure that the great painters through out history didn’t simply buy their pigments off the shelf of an artists supply store but instead mastered fundamental chemistry to create their own pigments. The same is true of our medium: if you don’t have a thorough understanding of your tools you will not be able to execute your artistic vision. For instance, if you are unaware, that the Leading Power Factor of lights that use Switch Mode Power Supplies (Electronic HMI, Fluorescent, & CFL ballasts, and LED power supplies) can cause them to use excessive amounts of power for the wattage of light they generate and to kick harmonics back into the power stream that can have a severe adverse effect on not only the generator, but also other electronic equipment operating on the same power, then you may never have the opportunity to create that great work of cinema because your HMIs wouldn’t hold their strike, your LEDs flickered, your Tungsten lights were excessively orange, your camera batteries wouldn’t charge, and your back up hard-drives locked up. For better or worse, cinematography is a technical medium. If you don’t master the technology, you will never have the control over the medium required to make great art.

 

- Guy Holt, Gaffer, ScreenLight & Grip, Lighting rental & sales in Boston

 

Totally agree Guy! I wasn't very clear in my message. I totally agree that a great idea and vision is worthless, if you don't know your tools and limitations, what I was trying to say is that sometimes with new technology and kit, young film students almost forget the craft they are meant to be expressing/learning and focus entirely on gadgetry, specs and trends. It's like with Iphone slates, whats the point, if you have a perfectly good professional slate?? We all like our toys and gadgets, but just don't replace what works with something that doesnt match up. That is a tragic step backwards within the industry.

 

You points are very relevant, and I would never underestimate the importance of safety and knowing what you are loading the circuits with. Otherwise life and reputation are at stake, and you could easily destroy some expensive kit.

 

It just makes me angry when I teach Cinematography and Lighting masterclasses to students around the world, who are all fixated with the specs and measurements, rather than what they see. Many of my early teachers like Freddy Francis BSC, would often confiscate lightmeters and zone system tables etc, and make the students just stand back and use their eyes. Once he had his basic exposure set, everything should fall into place relevantly, when it comes to contrast, colour and any planned grading or loss of quiality down the line.

 

With a bit of experience, it becomes very easy to incorporate most adjustments you may have in mind for the grade etc. Any DoP could tell you, that you can measure a LED light to be 3200K for example, but your eyes will say otherwise when you look at it. It's like blindly setting the whitebalance on camera to 'daylight', well quite often it may be technically correct, but to the human eye/brain it is clearly too blue. So what do you go with, your eyes (and the audiences eyes) or the number in the camera menu. You can tell the audience all day long that a specific shot was meant to be warm and high contrast according to your gadgets, but that doesn't really change the end look and result you are stuck with.

 

Especially nowadays with HD monitors almost displaying the end result on location. It is even easier to paint with light now, and if they did that whilst using LEDs, they would quickly remove them altogether. The day when fashion and beauty photography uses LED lights for their beautiful glow and attractive look, well that might be the day to consider LEDs as a serious contender in the film/media industry. As a lightweight camera light, or a means to fill in a car scene, great, as an alternative to all the tried and tested existing lights, no way Jose!

 

In the case of this student in Mexico, it sounds like the school have been SOLD the idea of low power LEDs and been told how great they are, when actually any DoP with some experience could tell you that LED lighting, as it stands today, is nowhere near as attractive on skin as tungsten or high CRI rated modern fluorescence.

 

My painting analogy was also misleading, because I have always built my own lights if needed, and really push the limits of what is available kit wise (and budget wise), my point was that you can't replace existing tools and mediums, with new ones that aren't up to scratch, purely because they are new and being talked about. It's very much like HD Cinema. In the right hands, and used wisely and with experience, it can look amazing and beautiful. In the hands of someone trying to be fancy by using HD video for the sake of it, it will end up looking quite bad and artificial, and not visually flattering to the audience. Combine that with dodgy looking LED lighting, and you have a recipe for a very fashionable esthetic disaster. ( In my opinion like parts of 'Public Enemy'. Even Johnny Depp looks awful and his skin looks absolutely terrible on the big screen, even the exteriors look spot lit by LED panels and look REALLY SYNTHETIC and super fake.)

 

Obviously inventing, testing and pioneering new technology and techniques excites all of us in this field of work, and it is vital to keep up with the current inventions,

but the new technologies must stand up to scrutiny and evolve by demand of the user, not by companies trying to be politically green, or trying to convince us their kit is best.

Very much like domestic energy saving bulbs. Nobody in their right mind would say they prefered the strangly green/yellow dull glow, that took 3 minutes to come on, when you enter a room. But because the users (public) said to the retailers 'this is no good, and doesn't replace the usual bulbs' they had to improve the technology, and are now pretty damn good.

 

I feel very strongly LEDs are the same, if we as users and customers don't refuse to use these inferior builds, well then they will be forced upon us and embedded in the industry. If we are brave enough to say, 'well actually they look pretty bad, and are unreliable', well then they might get improved much faster, as they have too much money invested.

 

I was at a media technology fair in the UK recently, and even the companies making the LED panels stated in their presentation, that most of their current LEDs were so varying in colour and lifespan, that their only way 'around' it was to mix up the LEDs and hope nobody noticed the differnces between units. Well that is just rediculous to me, and is not the way to 'improve' and 'replace' exsisting kit.

 

Like you say, I agree that you MUST know your tools in order to achieve your ideas (obviously), but image technology doesn't always make things nicer visually, just better technically. Nowadays I hear students arguing about codecs and resolution, when they hardly look at the footage to judge it in the first place!

 

In the early days of HDCAM, I would hire cameras with pro-mist filters or similar, for a drama/commercial/music promo shoot, and the techies at the hire houses were horrified that I wanted to 'distort' this expensive HD image I was paying for. To me that is the sometimes BIG difference between a technically knowledgable artist, and a pure techie who happens to work around cameras. It's the lazy 'fix it in post' people I am appealing to, not someone like yourself who obviously understands the nuts and bolts of the industry and its components.

 

Your points are even more relevant nowadays, with so many mixed technologies being thrown together on one location or circuit, so I know your article is super relevant. I just wanted to bring the discussion back to the origins of the skills and esthetics in photography, rather than just number crunching, which to a young film-maker can be very scary and off putting. Thats why we hire guys like you, to make sure we dont blow anything up ;)

 

This discussion started because this young student is facing an education using completely inferior lights, purely due to trends and green poilitics. I wanted to make his case about the art, and not the specs, which is the essence of cinematography.

 

My organic toothpaste joke was meaning to say, that if a student paid to study classical fine art in a university, and was told they could only use this new, politically correct paste, well then they are not being taught the original techniques and craft they signed up for. It may be progress, and I believe we must raise the bar, but for heavens sake at least let the students learn with a variety of kit, so they get the fundemental experience needed, and then later can find their own niche or prefered kit.

 

All in all, I agree with you totally Guy, I just wanted this student to fight for the right to learn the esthetics and complex craft of cinematography, rather than turn it into a matter of one piece of kit against another. Allthough the question is about one type of kit against another, the repercussions and consequenses of a school or industry investing in the wrong kit, are huge in the long term of the craft.

 

-Louie-

 

 

 

 

Louie Blystad-Collins DoP

www.louiebcollins.com

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The other nice thing about the Arri L series, I found out yesterday, is that they have optically metered colour, so as the LED emitters age, the colour shouldn't drift much. Apparently that calibration happens at switchon, but can be invoked manually.

 

They are, or rather will be once released, about $3k apiece, which I thought was surprisingly reasonable for a new technology with "Arri" on it. They reckon the 200W is equivalent to a 1K tungsten fresnel, which is probably reasonable for a high end LED. Litepanels make slightly less believable claims that would require LEDs to be eight or more times more efficient.

 

Litepanels tell me that they are aware of the PFC issue, and that their newest units have far better power factor, over .91, but they were vague as to exactly which units this affects and I shall try to find out more.

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The L7-C can do both tungsten and daylight, it did in the pre-NAB demo that Arri had here. It must cost more, because it has that outboard control panel. But if it's not too much, and the output is similar, why would the T or D models be viable?

 

 

 

 

 

-- J.S.

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The L7-C can do both tungsten and daylight,... It must cost more, because it has that outboard control panel. But if it's not too much, and the output is similar, why would the T or D models be viable?

 

In a permanent install application in a studio there is no need for the color tuning feature of the L7-C so why pay the extra amount whatever it is. When you are looking at buying 30 heads for a studio build out, I am sure the difference adds up. Same is probably true of newsrooms that have windows to the outside - why pay for color tuning when all you will ever use is 5600. Look for a new thread on the LED Fresnels being exhibited at NAB this year that I am starting http://www.cinematography.com/index.php?showtopic=51247

 

- Guy Holt, Gaffer, ScreenLight & Grip, Lighting & Grip rental & sales in Boston.

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