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HMI lighting with Phantom Gold HD


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#1 Bobby Shore

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Posted 24 September 2010 - 01:16 PM

Hey,

The forum's been really helpful with this topic already, but I had a couple specific questions that maybe you guys could help me out with. I'm shooting a hockey movie, and to accent some of the faster paced action-y type footage, we want to shoot some high speed work (specifically for some of the hockey fights in the movie). All the locations we're shooting in have existing metal halide fixtures above the ice, so to match the color temp., I'd have to go HMI instead of tungsten. Everything I've read so far has seemed somewhat favorable to using HMI's at highspeeds, although it seems a little more hit or miss with a 60hz cycle, even with electronic ballasts (I"m shooting in canada)

Has anyone used the phantom on int.'s with only HMI lighting? I know the existing fixtures will prove to be an issue as well (which I plan on testing next week), but do the same rules apply at higher speeds in terms of shooting at derivative frame rates of 20fps to avoid flicker? I don't think I have the lighting budget to kill the existing lighting and supplement the entire arena with my own. Also, I know with tungsten lighting at highspeeds you want to stick with 5K and up, is it the same for HMI? Would a 1.2 potentially be more of an issue than a 4K, or 12K?

Thanks in advance!

Bobby Shore
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#2 JD Hartman

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Posted 24 September 2010 - 07:39 PM

HID fixtures aren't the same as HMI's. They'll have a lower color temp (as low as 3700) and depending on their age, may likely have magnetic ballasts. Have you confirmed that the rink has MH and not mercury vapor fixtures? Did you do a sound test at the rink, depending on the insulation class, some ballasts are quite noisy. If you supplement the existing lighting with HMI, be prepared to color correct them to match the arena's fixtures, based on the suggestions on the Rosco Labs website.
As a sidelight or supplementary fill light, a 1.2k HMI isn't going to do much except for the closeups. For a 2.5k or larger, now you have to consider how you will power these guys up.
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#3 Mitch Gross

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Posted 25 September 2010 - 11:44 PM

The house lights will almost definitely NOT work. They will flicker like mad and color shift as they do. With the size of an arena, the lights will be on different legs, which means phases, which means the color shifting flicker will roll in waves across the different areas. Trust me, been there / done that. Won't work.

HMI lighting that uses high frequency electronic ballasts will not "flicker," but they can be prone to another artifact. This would be Arc Wander, where the hot spot of the electrical arc that travels in the plasmatic glass within the glass envelope moves back and forth between the two cathodes. The effect is more of a shimmer than a flicker. If there is one big light it is quite obvious, but if many lights are mixed together or if the light is punched through diffusion then Arc Wander often cannot be seen. Mind you I know what to look for so it's obvious to me.

It doesn't really matter what size HMI you use in this regard.

Don't know what kind of frame rate you're going for, but you will definitely need a lot of light. Most people treat the Phantom HD Gold around an ISO 250 or so. Using a 360 degree shutter gains you a stop, but remember that every time you double the frame rate you half your exposure time.

Let me know if I can offer any additional assistance. As the North American distributor for Phantom products, it is our business to support them.
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#4 Bobby Shore

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Posted 26 September 2010 - 06:27 PM

The house lights will almost definitely NOT work. They will flicker like mad and color shift as they do. With the size of an arena, the lights will be on different legs, which means phases, which means the color shifting flicker will roll in waves across the different areas. Trust me, been there / done that. Won't work.

HMI lighting that uses high frequency electronic ballasts will not "flicker," but they can be prone to another artifact. This would be Arc Wander, where the hot spot of the electrical arc that travels in the plasmatic glass within the glass envelope moves back and forth between the two cathodes. The effect is more of a shimmer than a flicker. If there is one big light it is quite obvious, but if many lights are mixed together or if the light is punched through diffusion then Arc Wander often cannot be seen. Mind you I know what to look for so it's obvious to me.

It doesn't really matter what size HMI you use in this regard.

Don't know what kind of frame rate you're going for, but you will definitely need a lot of light. Most people treat the Phantom HD Gold around an ISO 250 or so. Using a 360 degree shutter gains you a stop, but remember that every time you double the frame rate you half your exposure time.

Let me know if I can offer any additional assistance. As the North American distributor for Phantom products, it is our business to support them.


Hey Mitch,

Thanks so much for the reply. For the houselights, even though I'll be testing this week, sounds like I'll have to kill them and just supplement everything with my own lighting. We have enough big guns that this won't be a problem, especially after having talked with the director and keeping everything high speed relatively tighter in value.

So 250 for the ISO? I've heard of people rating it up to 500 and the results turning out great, definitely will be part of the testing.

@JD, thanks for the info as well. The lights are definitely metal halide, but we;re shooting in a couple different rinks and they have varying degrees of newer/older heads, so it'll definitely be something to watch out for in terms of matching color temp to the HMI lighting. As for power, we'll be sorted so as to run bigger heads further away and diffused.

I'll keep you posted on the results of the test. Thanks!

Bobby
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#5 Mitch Gross

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Posted 26 September 2010 - 10:03 PM

Big question is how fast do you plan to roll? Nothing eats up the T-stops faster than rolling crazy fast frame rates. You will need a LOT of light if you plan on shooting 1000fps (that's 5.25 stops loss compared to 24fps).
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#6 Bobby Shore

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Posted 05 October 2010 - 11:15 AM

came across this last week... could prove useful:

high speed ballast

bobby
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#7 Bobby Shore

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Posted 19 November 2010 - 06:11 PM

so we did our piece with the phantom over the last week or so. only hmi lighting, mostly 18's through 12 by light grids, and a couple 6k and 4k's, also diffused, and some data flash units in the BG. shot with 360 deg. shutter, rated @ 400, and shot 360 fps, 600 fps, and 800 fps. without any noticeable flicker. kinda goes against everything I read/researched, always hearing that 360 fps was the highest you could go with hmi lighting. used regular electronic flicker free ballasts.

anyways, thought I'd share, wasn;t expecting it to work.
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#8 oscar jimenez

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Posted 15 April 2011 - 01:23 PM

Mitch,
Ive just used a phantom gold hd from a rental in south america, they warned us that we were not allowed to use hmi lightning at all, regardelss they were Flicker Free Electronic Ballasts or magnetic, so we had to change all our package for zillion tungsten units to fill the needed t stop x 1000 fps shooting large exteriors at night, you can imagine the kind of nightmare, we tried a 1200 Arri Flicker free HMI just to test and there was a lot of flicker, so is that possible that this camera cannot be used with HMI lights, now that we are living on the 21st century? we had another issue, with noise on black or dark areas, even though we were correctly exposed, and then a kind of vertical pattern on the image as well, that happened on the second shooting day, the footage looks terrible with that pattern over it, Please, for any future, certainly cannot use HMI lights with this camera, at 250 fps even had flicker with a 360 or 180 shutter!!!, please give me any clues if you can, Ill really appreciate it.
Best regards
Oscar

The house lights will almost definitely NOT work. They will flicker like mad and color shift as they do. With the size of an arena, the lights will be on different legs, which means phases, which means the color shifting flicker will roll in waves across the different areas. Trust me, been there / done that. Won't work.

HMI lighting that uses high frequency electronic ballasts will not "flicker," but they can be prone to another artifact. This would be Arc Wander, where the hot spot of the electrical arc that travels in the plasmatic glass within the glass envelope moves back and forth between the two cathodes. The effect is more of a shimmer than a flicker. If there is one big light it is quite obvious, but if many lights are mixed together or if the light is punched through diffusion then Arc Wander often cannot be seen. Mind you I know what to look for so it's obvious to me.

It doesn't really matter what size HMI you use in this regard.

Don't know what kind of frame rate you're going for, but you will definitely need a lot of light. Most people treat the Phantom HD Gold around an ISO 250 or so. Using a 360 degree shutter gains you a stop, but remember that every time you double the frame rate you half your exposure time.

Let me know if I can offer any additional assistance. As the North American distributor for Phantom products, it is our business to support them.


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#9 Mitch Gross

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Posted 17 April 2011 - 05:53 PM

This 21st century camera is revealing the limitations of a 20th century lighting instrument.

Sometimes people will mix in a bunch of HMIs and this will help hide flicker so they "get away with it." but as you tested, they can flicker. Every individual light will be a little different, and will react differently based on the harmonics of the local power on the day. It really is a crap shoot with HMIs in high speed.

As to your noisy blacks and vertical striping, it sounds like you needed to black balance the camera more often (aka current session reference). An experienced Phantom Tech would know this.
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#10 Sean Fredregill

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Posted 23 June 2011 - 10:27 AM

Hi Mitch.


What high-frequency HMI's have you had good luck with? I am hopefully going to shoot my first Phantom spot soon and looking at my options.

Many Thanks.

Sean Fredregill
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#11 jason berman

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Posted 25 June 2011 - 08:47 AM

HI Sean
if u want to be reliant that u will not have any potential for flicker, do not use HMI;s, even if they say Flicker Free, they only mean flicker free at normal speeds up to about one hundred fps not above.
These ballasts are not designed for slow motion only for overcranking a normal camera like a 435 or hssr3 etc.

There are high speed ballasts that arri make, but are quite rare, they are designed for real high speed use, but i would still test them.

There is a lot of misinformation out there on this subject.
There are a lot of people including Lighting Dept who think that Flicker free is Flicker free at any fps, and also who have never had a problem with HMI's, I do admit that i have done a lot of shots with HMI's and they have been acceptable.
BUt i would never bet your bottom dollar that a normal HMI light will not flicker at high speed, its kind of hit and miss.
If used in sunlight there is a strong possibility (but not guranteed) that Flicker would not be visible if u are just supplementing Sunlight with HMI , but if the sun drops and u end up lighting the scene with hmi as the main light, cross your fingers.
Do not think about using an HMI interior as you only source of light.

IF u want to use HMI for daylight balanced reasons or any reason u think its worth the risk, roll with all the tungsten lights just in case u get flickering results.


Lights that are 100% stable at high speed.
5k tungsten and larger
Vistabeams
Longstrikes, Luminys lights.

There are some LED lights that work, but there are some that dont, so test.
Use mirrors and bounce to get the light in spaces that another light would normally be used.
There are other lights that can work, but never rely on them.

This is my experience, of using high speed cameras everyday for the last 5 years.
If anyone has any other input please list it here.

Everything about what i advise is to keep it 100% safe, you can of course take more risks, u may get some great results, but your more than likely get some flicker on the way.

Jason Berman
Love High Speed
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#12 Matias Nicolas

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Posted 20 March 2013 - 07:19 AM

GReat info ! i'm shooting my first comercial with Phantom Gold, cause the Flex is not avaliable . Which real sensibility is the gold at 25 fps ?

And I never shot with a 20 Kw fresnell .. Do you know , aprox... , If I shoot at 600 fps, at which distance , should I put that source without difussion? 


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#13 Stephen Price

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Posted 17 April 2013 - 03:18 AM

300/1000Hz HMI ballasts are available and can power any HMI lamp up to either 4K or 6K with stable power. In most cases Arc Wander can be entirely eliminating with these ballasts, there are some circumstances that some form of flicker may still be apparent. Testing is always advised if possible. 

 

There are now many other daylight balanced professional light systems available which do not flicker under high speed photography. Many can be used as particle sources, or lamps for confined spaces, many of these heads are much more power efficient with low heat output.

 

Stephen

Love High Speed

www.lovehighspeed.com 


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