Jump to content


Photo

Best fixtures for Phantom setup

phantom HD Gold

  • Please log in to reply
20 replies to this topic

#1 Kenny Evans

Kenny Evans

    New

  • Basic Members
  • Pip
  • 5 posts

Posted 23 October 2013 - 10:44 AM

Hi,

 

Been a lurker many years but need some advice on lighting fixtures. 

 

We have a Phantom HD Gold in our studio which lives in there all the time. Up until now we've been using a mixture of Kino, Dedo and Colortran fresnels to light scenes using different phases in the studio to negate flicker with the tungsten. Most of the stuff we do is small table top stuff but we now want to be able to light our entire studio cove (5 metres high 10 metres across) and have some money to achieve this. When we've had bigger shoots, lights have always been hired in on a job specific basis.

 

We have a single 32 amp socket with appropriate connector and 3 dimmer banks orated at 40 amps each running 16 amp connectors with DMX control. I have about £15k to spend and have been looking at getting up to around 6-8k with possibly a single 4k key on the dedicated 32amp socket and then maybe 2-3 additional 2k's on the other connections. I've been looking at Arri D40's and M18's with HMI/Ballast but wanted peoples thoughts on what might be a better more economical route giving us the most for our money and maybe taking in current LED technology. We were also looking at a new Dedo which was touted as around 2k output but doesn't appear to have been released yet. Not sure of the model name but saw it at a trade show some months back.

 

Any input or suggestions appreciated.


  • 0

#2 Phil Rhodes

Phil Rhodes
  • Sustaining Members
  • 11944 posts
  • Other

Posted 23 October 2013 - 11:50 AM

I recently wrote an article about LED efficiency (in both the cost and electrical sense) for Red Shark News.

 

The recap is this: LED is not much more efficient than either HMI or fluorescent in even the best case. LED of any quality is also much more expensive per photon than HMI (Zylight F8 90W LED = US$2400ish, Arri 575 HMI = US$5500ish for four to six times the light).

 

The upsides of LED are physical robustness, hot restarting (which may interest you if you don't want to have your studio be dazzlingly high-frame-rate bright between takes), and yes, flicker free operation - assuming the guy who designed the drivers was awake and facing in the right direction. Colour rendering is worse than HMI.

 

Current best photons for the money is fluorescent, although obviously it's a bit limiting. Current best photons for the power is probably HMI. 

 

This is very rapidly changing, both because the tech is changing and because LED is currently at early adopter prices. The conclusions may be different in a year or eighteen months.

 

P


  • 0

#3 Kenny Evans

Kenny Evans

    New

  • Basic Members
  • Pip
  • 5 posts

Posted 24 October 2013 - 04:21 AM

We already have a fairly large array of Kino's, about 22 fixtures, but they are pretty useless in most ultra slow applications because of their fall off, no focus ability and size.


  • 0

#4 Guy Holt

Guy Holt
  • Basic Members
  • PipPipPipPip
  • 535 posts
  • Gaffer
  • Boston

Posted 27 October 2013 - 11:29 AM

We already have a fairly large array of Kino's, about 22 fixtures, but they are pretty useless in most ultra slow applications because of their fall off, no focus ability and size.

 

The problem I find with a lot of the alternative light sources (LED, LEP, etc) is that they are not available is the same wide array of form factors (cyc, far cyc, open face, single par, nine-light par, fresnel) as good old tungsten lights. The obvious light configuration for lighting a studio cyc would be a spacelite – two spacelites will evenly light a 40’ wide cyc wall, cove, and the floor out to the action area, and even provide a soft kicker for talent as well. Yet where LED spacelites are available they are outrageously expensive compared to the tungsten variety.  

 

chromakey4lg.jpeg

 

IMO, Kenny would do best to invest in a couple of Mole 12kw spacelites. 12kw verses the standard 6kw for the higher output he will need for high-speed  work.  Like the 6kw versions, they are wired in six 2kw circuits, with a soco connector. A soco break-in will enable him  to distribute two circuits on each phase leg and thereby eliminate the flicker he would normally get from the small 1kw tungsten filament. So that he doesn’t have to use his smaller Colortran Fresnels in clusters of three (one on each phase leg) to eliminate flicker, I would also suggest he convert the power supplying the fresnels to DC.  Any tungsten lamp can operate DC as well as AC, and operating a 2k Fresnel DC will give him the compact size he wants, as well as collimated light that can be  focused and will not drop off the way his Kinos do.

 

CPS_Cultivate_Studio_HS_Prod.jpg

 

In response to a DP’s recent posting on the CML, where he was looking for some way to power a chandelier flicker-free for a high-speed commercial shoot shoot (pictured above), I built him a 120V AC to 120V DC power converter so that he could power the chandelier and other practicals flicker free at high speeds. He shot with it several weeks ago and reported that it “performed beautifully” and at  “2,000fps was rock solid.” 

 

CPS_30A_Power_Converter_SM.jpg

 

The one I built for him could handle up to a 1000W tungsten load, but I have since scaled up the design to handle a Jr. with CXZ lamp. The larger converter (pictured here) will accept input AC voltages from 90-140V, and 190 – 250V and put out a constant 120V DC. It can operate at both 50 and 60 Hz. It also has a series LED display to indicate the total load put on it between multiple tungsten Fresnels and incandescent practicals.

 

And, as you can see in the picture above, it is a lot smaller and lighter and more easily concealed on a set than ten 12V deep cycle marine batteries, wired in series, which has been the traditional approach to powering tungsten lights with DC on stages.

 

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


  • 0

#5 Stuart Allman

Stuart Allman
  • Basic Members
  • PipPipPip
  • 179 posts
  • Cinematographer
  • San Diego, CA

Posted 28 October 2013 - 02:22 PM

Kenny,

 

Have you had an opportunity to evaluate Hive plasma lights?  They come in fixtures similar to a tungsten unit and don't flicker at any frame rate.  The lights are daylight balanced (5600K) and do not dim without going severely blue (12000K-ish), but supposedly offer better color rendering than HMI at 100% output.  Unfortunately the fixtures tend to be boutique priced last time I checked, but they might fit into your particular budget (just not mine).  Hope this helps.

 

S.

-------------------------

illuma.blogspot.com


  • 0

#6 Phil Rhodes

Phil Rhodes
  • Sustaining Members
  • 11944 posts
  • Other

Posted 28 October 2013 - 03:18 PM

I think that's the LEP that Guy mentioned.


  • 0

#7 Stuart Allman

Stuart Allman
  • Basic Members
  • PipPipPip
  • 179 posts
  • Cinematographer
  • San Diego, CA

Posted 28 October 2013 - 04:00 PM

I was wondering what he meant by LEP.  I've never seen that acronym used before with regards to plasma lights.

 

S.

-----------------------------

illuma.blogspot.com


  • 0

#8 Phil Rhodes

Phil Rhodes
  • Sustaining Members
  • 11944 posts
  • Other

Posted 28 October 2013 - 05:17 PM

Luxim, who make the drivers for all current LEP products, call it light-emitting plasma.

 

Although I'm a bit cautious about their website which shows tungsten, LED, discharge and LEP lighting on a sort of matrix with two axes of "output" and "innovation".

 

I don't particularly care how innovative something is so long as it works!


  • 0

#9 Kenny Evans

Kenny Evans

    New

  • Basic Members
  • Pip
  • 5 posts

Posted 31 October 2013 - 06:34 AM

Thanks for all the replies. I've been digging around further and I'm thinking of a combination of everything we have plus 4 extra fixtures might be enough. I've been looking into the space lighting fixtures but my only problem with those is that you often get stuck with a certain look in that the light for the cyc is what lights the subjects and with so much flying around there's little latitude for modelling of any kind, especially at full length. We're going to demo some D40's and M18's and see how they fare. As we rarely shoot full length people at more than about 600 fps this may be sufficient with a fast lens of f2 or less.


  • 0

#10 Kenny Evans

Kenny Evans

    New

  • Basic Members
  • Pip
  • 5 posts

Posted 31 October 2013 - 09:09 AM

I've been speaking to an industry contact today who has suggested we look into Hive lights and the Lab Light systems. One is about 30k and gives you a ten second burst, perfect for our setup at 1000 fps plus as we only get around 4-6 seconds at that frame rate. 2 of these may give us what we need to light the cyc and provide key which we could bounce for fill etc. I'm going to test them soon so I'll let you know how it goes!


  • 0

#11 Shelly Johnson ASC

Shelly Johnson ASC
  • Sustaining Members
  • 34 posts
  • Cinematographer
  • California

Posted 31 October 2013 - 10:46 PM

Hi Kenny,

 

Here's an old-school type of reply. When dealing with the tungsten strobing on Phantom (I believe certain tungsten lights tend to strobe at frame rates of 300FPS and above, with severe strobing at 1,000-2,000FPS). It seems like the smaller the globe, the more noticeable the strobing. For instance, a 1K or 750 Source 4 strobes more than a 10K or 20K at higher frame rates. Certain Kinos will strobe less, but thats a bit of a roll of the dice... and as you mentioned, the output isn't overly useful at high frame rates. The use of a space-light will likely produce severe strobing since that light is comprised of (usually) 6 1K quartz globes. Almost anything below a 2K tungsten lamp is subject to strobing at high frame rates. 

 

My solution has always been to use lamps with larger globes, then diffuse, bounce, reflect... whatever... to shape the light as needed. Seems like this old tried-and-true method will get the best results with the fewest headaches.

 

My thoughts on using newer lamps, such as LEDs, Plasma Sources Hive or SoftSun, are that they are lamps that already have inconsistencies with regard to color and phasing. I've had difficulty (as has everybody) with strobing LEDs at 24FPS, let alone highspeed applications. The Phantom already has a limited eye when it comes to contrast and color rendition, so there is already less of a fudge-factor than you'd have with, say, an Alexa (under normal speed conditions). I've always had luck choosing sources that had full and predictable color fidelity (good ol' tungsten). Often, integrating daylight is a great idea, with the sensor's native color temp closer to daylight... and I've used solid state HMIs with The Phantom without strobing, but feel I was lucky. Technically speaking, the HMIs should have strobed, so maybe some testing if you use those. Obviously you're limited with dimming abilities of HMI sources.

 

Large tungsten lights seem to answer what the camera is asking for, in my experience.

 

I'd be curious to hear what you ultimately use! If there is another technique out there, I'd love to know.

 

Best regards,

 

Shelly


  • 0

#12 Guy Holt

Guy Holt
  • Basic Members
  • PipPipPipPip
  • 535 posts
  • Gaffer
  • Boston

Posted 01 November 2013 - 12:57 PM

The use of a space-light will likely produce severe strobing since that light is comprised of (usually) 6 1K quartz globes. Almost anything below a 2K tungsten lamp is subject to strobing at high frame rates. ...I'd be curious to hear ...  If there is another technique out there, I'd love to know.

 

 

A tried and true approach to using spacelites without flicker is to distribute their individual circuits over the three phases of the electrical service to the stage. The reason small incandescent globes flicker is that the heating and cooling of their tungsten filaments every half cycle of the AC waveform results in uneven exposure at high frame rates.  If instead of operating the six circuits of a spacelite on a single phase leg so that all of the tungsten filaments are getting brighter and dimmer in unison, you distribute two circuits on each of the three power phases, the filaments on one phase leg will be getting brighter as another is getting dimmer because of the 120 degree phase shift between the electrical phases. The net effect is constant output from the spacelite after the output of the three phases blend together inside the silk. A soco break-in makes it very easy to distribute two circuits  of either a 6k or 12k spacelite on each phase leg and thereby eliminate the flicker one would normally get from the small 1kw tungsten filament. And, if Kenny is worried about the spacelite serving as a kicker or back light for his talent when he doesn’t  want it to, a 4x4 solid is all that is needed to cut it off areas of the set.

 

A new technique for eliminating the flicker from small tungsten filaments is to convert the power to DC.  Any tungsten lamp can operate DC as well as AC. Operating a 1 or 2k Fresnel DC will give Kenny the compact size he wants, as well as collimated light that can be focused and will not drop off the way his Kinos do.

 

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


  • 0

#13 Shelly Johnson ASC

Shelly Johnson ASC
  • Sustaining Members
  • 34 posts
  • Cinematographer
  • California

Posted 01 November 2013 - 06:52 PM

Regarding Guy's comments,

 

Correct on all counts. Great tips there. I've never thought about the DC thing. I'll try that one!

 

This is why a cinematographer needs a creative gaffer!


  • 0

#14 Phil Rhodes

Phil Rhodes
  • Sustaining Members
  • 11944 posts
  • Other

Posted 01 November 2013 - 08:15 PM

I'd be interested to know how the DC converter was achieved. There's effectively two technical approaches, but the ammeter appears to go into double digits and I'm not sure there's enough capacitors in the world to do it one of the two ways!


  • 0

#15 Stuart Allman

Stuart Allman
  • Basic Members
  • PipPipPip
  • 179 posts
  • Cinematographer
  • San Diego, CA

Posted 01 November 2013 - 08:55 PM

Speaking as an EE who moonlights as a camera person, 1-2kW isn't really that difficult of a design.  I was once involved in a 1.2kW design.  Now when you get to 10-20kW things get a bit out of my comfort zone.

 

However, as Shelly pointed out, it really depends on the bulbs mass/thermal time constant.  3-phase power might be the easiest way to go.  I once did some tests with the FS-700 and various tungsten fixtures just to see where things are truly noticeable.

 

http://videogearsand...rate-video.html


  • 0

#16 Rob Vogt

Rob Vogt
  • Basic Members
  • PipPipPipPip
  • 437 posts
  • Other
  • New York

Posted 01 November 2013 - 09:01 PM

Well I'd imagine you'd need quite the large power supply. http://www.cisco.com...c78-571946.html Would do the trick although there may be, and probably is, some more specialized stuff out there.


  • 0

#17 Guy Holt

Guy Holt
  • Basic Members
  • PipPipPipPip
  • 535 posts
  • Gaffer
  • Boston

Posted 02 November 2013 - 11:00 AM

Well I'd imagine you'd need quite the large power supply. http://www.cisco.com...c78-571946.html Would do the trick ....

 

This would work if you wanted to operate your fixtures dimmed to less than 50% since its’ max output is 50V DC.  What I am proposing is that Kenny operate his Colortran Fresnels at 120V DC so that he doesn’t lose any output or suffer any color shift.

 

One of the biggest challenges in designing our converter was maintaining the DC Voltage output regardless of variations in the AC line voltage input. The effect of voltage drop on tungsten lights can be dramatic because their output falls off geometrically as the voltage decreases. For example a 1k lamp operating at 90% rated voltage (108V) produces about 68% of its normal light output - your 1kw lamp is now a 650W lamp. But, that is not all, as the light intensity decreases, so does the Kelvin color temperature of the emitted light.

 

CPS_30A_Power_Converter_guts_SM.jpg

 

For this reason, I have included in our power converter a 25-tap toroidal autoformer (see picture attached.)  Control circuitry monitors the incoming AC line voltage (120V, and 208V, 230V, 240V single phase) and automatically switches to the tap that will put out 120V DC  ±4% anywhere within AC voltage ranges of 88 to 134 and 170 to 264 volts. It will operate on both 50 and 60 Hz.  Our toroidal autoformer is not sensitive to small errors in line frequency, making it ideal for use with generators. The power converter features a switch grade breaker that offers 30A over-current protection. It’s power cord is wired with a 60A Bates plug, but it can also be used on a standard wall outlets with an Edison plug cord that has a 20A fuse in it.

 

CPS_30A_Power_Converter_LED_SM.jpg

 

The power converter has proven to operate small incandescent practicals and smaller quartz movie lights flicker free up to 2000fps (we have yet had the opportunity to test it at faster frame rates.) The rule of thumb has always been that any quartz fixture smaller than a 5k would flicker at such high speeds, but with this power converter you can now use quartz fixtures smaller than 5k flicker-free. The series LED amperage indicator (see picture above) enables you to monitor total load put on the power converter between multiple small tungsten Fresnels and incandescent practicals. And, it is a lot smaller and lighter and more easily concealed on a set than ten 12V deep cycle marine batteries.

 

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


  • 0

#18 Phil Rhodes

Phil Rhodes
  • Sustaining Members
  • 11944 posts
  • Other

Posted 02 November 2013 - 02:10 PM

Try it with twenty batteries, as you'd need here!

 

Is that a switching converter, after the voltage-normalisation transformer, or just a big conventional rectifier? I can see some lightweight control electronics at the bottom of the interior shot, but that might just be the metering.


  • 0

#19 Kenny Evans

Kenny Evans

    New

  • Basic Members
  • Pip
  • 5 posts

Posted 04 November 2013 - 06:09 AM

I've certainly seen that the bigger the lamp - the less the flicker but always put it down to the fact that such a large lamp doesn't actually dim enough between cycles to be noticeable.

 

Test driving some plasma/xenon spacelights hopefully this week.

 

Thanks for all the replies, much appreciated.


  • 0

#20 Rod Gammons

Rod Gammons

    New

  • Basic Members
  • Pip
  • 1 posts
  • Other

Posted 04 November 2013 - 01:08 PM

I designed a special Ringlight System for use with the Phantom. The Rotolight ANOVA V2.  It has a 19mm railmount option for taking the camera and light rig together on a 360 an and tilt setup. It gives you a choice of either 110 degree supersoft super wide lights for getting in close or 50 degree really punchy lights.  Either way you get completely flicker free (at ANY frame rate) CRI of 95 or better (skintone R15 =98).   It just won a Cinegear tech award, BKSTS award and was voted Lighting product of the year 2013 .

Each light in the rig draws less than 50 watts at full output delivers is the equivalent of up to 3.5kW (per light) . Electronically colour controllable from 3150K to 6300K.

mg_9474.jpg


  • 0



Broadcast Solutions Inc

Media Blackout - Custom Cables and AKS

FJS International, LLC

Opal

The Slider

Wooden Camera

Rig Wheels Passport

CineLab

Visual Products

Ritter Battery

Glidecam

rebotnix Technologies

Willys Widgets

Tai Audio

Gamma Ray Digital Inc

Abel Cine

CineTape

Paralinx LLC

Technodolly

Metropolis Post

Aerial Filmworks

Technodolly

CineLab

Paralinx LLC

Willys Widgets

Tai Audio

Broadcast Solutions Inc

FJS International, LLC

Gamma Ray Digital Inc

Ritter Battery

Rig Wheels Passport

Wooden Camera

The Slider

Abel Cine

Visual Products

Media Blackout - Custom Cables and AKS

CineTape

Opal

Metropolis Post

rebotnix Technologies

Glidecam

Aerial Filmworks