UV lights causes scrolling bar in video

S

SDesign

Member
I was shooting some video at a local manufacturing facility today and discovered that when there are UV light being used for curing I get a scrolling bar across the entire video like I had the shutter set improperly. I was shooting with a Canon 60d at 30P with a shutter of 60fps. I assume that the UV lights are at a different cycle than the florescent ones used to light the facility and that is why I am having the issue.

Has anyone encountered this before? If so, are there any solutions for being able to get useable video under UV lights?

Other footage shot in the same area (same settings) of a different machine without UV being used for curing was fine. And shots of the offending machine were fine so long as the UV could not infiltrate the lens/sensor.

Any help would be greatly appreciated.
 
Bump, Any suggestions? Perhaps I will try to increase the shutter to 120 and see if that works. I will be shooting some additional footage on Friday or Monday.
 
I've never had the issue; if I found this problem, I think I'd try to play with the sutter to see at what frequency that light is pulsing, then try to work out a shutter speed that won't mess with neither the regular nor the UV light; there may just be no way to escape, though

edit: one way out may be to use your own LED panels for lighting, and turn the site's regular lights off; then you can set the shutter to whatever value the UV light asks for
 
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We've been testing the growing crop of theatrical and television LED fixtures extensively against NTSC and PAL in various resolutions and framerates. As some LED fixtures dim or cycle into different colors, we've noted that several (usually less-expensive fixtures) exhibit the rolling effect you're describing and not the strobing we'd expected. I know of one brand of LED truss warmers that had to be pulled from a large concert tour with NTSC-based iMag because the entire truss began rolling like an old CRT monitor when shot without clear-scan.

It pays to test your new fixtures (esp., LED) before integrating them into your lighting package.
 
Isn't this a trick to make the LED look brighter for the eye? Feed it with more power than actually allowed, but switch it off between to allow it to cool down – afaik doing this with the right frequency makes the eye ignore the gaps and just think that the LED is always as bright as when running with more power than allowed.
Just an idea – but I could imagine this is a reason for that, especially if the devices are running with AC instead of DC and therefore are using a frequency they think is best.

Simon
 
I have seen exactly what Olson is describing. It gets worse at 60P. here is a video I produced for a church and their LED lighting was rolling and strobing. I left it in because we had little choice and could esthetically get away with it in this piece. You can see what I mean bellow in the opening shot. Of course some of the shots are the lights blinking and color changing by program, but the opening shot is very noticeable.

 
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