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HMI Flicker/Pulsating @ 1000fps with flicker free ballast

HMI Flicker Pulse highspeed 1000fps flickfree ballast

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#1 Ash Barron

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Posted 02 February 2016 - 12:45 AM

I was shooting with the phantom 4k at 1000fps all day with HMIs (18k and 6k) on flickerfree ballasts.

 

All was fine until towards the end of the day when they started pulsing. I figured it might be a power surge or something?

 

Anyone experienced this before?


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#2 Robin R Probyn

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Posted 02 February 2016 - 12:58 AM

were you shooting outside with ambient day light ?..  just wonder as maybe you had the flicker the whole time but noticed more as the ambient day light went down.. ? 


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#3 Ash Barron

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Posted 02 February 2016 - 12:59 AM

No, sir. All studio work and only used those 2 units until the point of pulsing..


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#4 Robin R Probyn

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Posted 02 February 2016 - 03:09 AM

Ah.. ok sorry.. just a wild guess sir.. 


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#5 Ash Barron

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Posted 02 February 2016 - 03:12 AM

Thanks for trying!


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#6 John E Clark

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Posted 02 February 2016 - 12:58 PM

I was shooting with the phantom 4k at 1000fps all day with HMIs (18k and 6k) on flickerfree ballasts.

 

All was fine until towards the end of the day when they started pulsing. I figured it might be a power surge or something?

 

Anyone experienced this before?

 

From this site there is mention of 'arc wander' which affects HMI lights and may be produced independent of the power source. Don't know if this is your problem... but it could explain at least one pathway to 'flicker'... that is not based on power supply variations.

 

 

http://www.lovehighs...for-high-speed/


Edited by John E Clark, 02 February 2016 - 12:59 PM.

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#7 Jeo

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Posted 18 July 2016 - 11:18 AM

I had a very similar issue.

I shot with 2 18k and 3 6k. 

Everything was fine for about a day and a half then both 18k started to flicker. 

 

Fortunately I was planning to finish the day with the 6k anyway so all was fine but I'd like to find a way to reliably use 18k's in the future. 

The ballasts we had were running at 300 maybe if we had 1000hz ballast we'd be better off. 


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#8 Jean G

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Posted 18 July 2016 - 03:12 PM

This problem could appear when loads are not equally divided over the phases.


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#9 Jon Kline

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Posted 18 July 2016 - 04:47 PM

Are the lamps relatively new?


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