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High Speed Video Lighting


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#1 Ryan Smith

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Posted 25 February 2009 - 02:31 PM

I'm working with a high speed camera at rates from 500-10000 fps, I need a lighting set up for medium-small products and have been looking into flicker free HMI. I recently demoed a K5600 joker 800 watt HMI and the results from the footage show no noticeable flicker at 6200 fps. We did not have the unit long enough to do multiple tests at different frame rates.

Does any one have experience using these lights for High Speed Video? If so, How did they work out for you? Any alternatives you might suggest? At what frame rate did flicker become a problem?

Thanks
Ryan
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#2 JobScholtze

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Posted 25 February 2009 - 03:48 PM

I'm working with a high speed camera at rates from 500-10000 fps, I need a lighting set up for medium-small products and have been looking into flicker free HMI. I recently demoed a K5600 joker 800 watt HMI and the results from the footage show no noticeable flicker at 6200 fps. We did not have the unit long enough to do multiple tests at different frame rates.

Does any one have experience using these lights for High Speed Video? If so, How did they work out for you? Any alternatives you might suggest? At what frame rate did flicker become a problem?

Thanks
Ryan

Hi Ryan

It all depends on the lightbulb itself. We had a few flicker free hmi light and it took some time to figure out wich one was still making a flicker in the picture. When we changed that bulb to a new one t was gone. We had that on several shoots. The last shoot we did i used 32k lights, no problem whatsoever. So make sure you get new bulbs
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#3 Julian Cheng

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Posted 25 February 2009 - 04:44 PM

Hi Ryan,
Last week I shot with weisscam in Shenzhen, China. the only version I got is the HS-1. The most frame rate I can get is 1200 fps with 720X480. With the arri 100mm macro lens, I use two 5K Spot (tungsten) to just achieve a very close-up shot on a mobile phone. Almost 90% of the shots I need to wide open the iris because the ASA of that HS-1 weisscam is just 160. I choose tungsten light because I know I never can get a real flicker free HMI in China area (everywhere are clone HMI and I can see it flicking with my eyes.....@_@)
I guess you use 12K or 18K at least....for me, next time if I need highspeed, I will book the 10K and 20K Spot......@_@
This is all the experiences I got. Hope it can help.
Yours,
Julian
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#4 Rob Vuona SOC

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Posted 25 February 2009 - 07:33 PM

I'm working with a high speed camera at rates from 500-10000 fps, I need a lighting set up for medium-small products and have been looking into flicker free HMI. I recently demoed a K5600 joker 800 watt HMI and the results from the footage show no noticeable flicker at 6200 fps. We did not have the unit long enough to do multiple tests at different frame rates.

Does any one have experience using these lights for High Speed Video? If so, How did they work out for you? Any alternatives you might suggest? At what frame rate did flicker become a problem?

Thanks
Ryan


Hey Ryan,
Jeff Silverman owns 3 or 4 of these cameras and can give you all the info you need
954-232-8503
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#5 William Coss

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Posted 25 February 2009 - 09:46 PM

Dedolight manufactures a light head that is specifically designed for high speed cinematography.
It concentrates an intense amount of light over a highly concentrated area with little or no heat.

Dedocool 3200 K and operates between 110v thru 240v.


It's hard to look at these lights when they are on.


Bill
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#6 RobVanGelder

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Posted 27 February 2009 - 06:42 AM

Having done a good amount on High Speed cameras (Speedcam, Phantom) the main concern with HMI is the inconsistent behavior of the lamps.
While they are flicker free electronically, in general the hot gas-plasma arc inside the bulb can start to rotate and wobble, giving uneven intensity and colors.
We found that smaller lamps than 4Kw will often introduce flicker, so for that we use 6Kw or bigger.
Bu it is slightly counter productive: the more gas (the bigger the bulb), the higher the chance for this plasma-disturbance.
Age of the bulb does not always matter.

Smaller lamps, like the Joker 800, might do well, as they have a very small and concentrated plasma-arc.
I do not know the frequency of the Joker ballast, but apparently it worked for you. With the Arri 75Hz Flicker-free setting it is not always guaranteed.
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#7 Ryan Smith

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Posted 04 March 2009 - 02:08 PM

Thanks for all the advice, everyone has been very helpful.

I am bringing in a few more demo kits this week to compare some higher wattage HMI with the joker 800

-Ryan
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#8 William Coss

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Posted 04 March 2009 - 11:53 PM

Ryan,

Just wondering what city you are in.

Bill
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#9 Ryan Smith

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Posted 10 March 2009 - 11:51 AM

Ryan,

Just wondering what city you are in.

Bill


Seattle, WA
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#10 Jess Haas SOC

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Posted 11 March 2009 - 01:41 AM

With high speed testing the actual fixtures to be used seems to be the best thing to do. I have seen identical lights where one had noticable problems and the other didn't. I have also seen 1k pars that the high speed tech claimed would flicker like crazy produce no noticable flicker at 1500 frames/second.

~Jess
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