practical bulbs in shot

[Andrew Greenan]

hi there. i'm playing with the idea for a music video of seeing loads of practical bulbs in shot, in a dark space.

i've noticed that this will tend to cause flare. if i dim them down, and have enough, could this help to reduce flare and still give enough stop for the artist's face? and would using a polariser reduce lens flare at all?

 

in The Sultan Sea, there is a scene where Val Kilmer's character is buying a gun. the camera tracks past a lightbulb, which just glows white, and gives no flare whatsoever. Could the bulb be painted white and dimmed down?

 

would appreciate comments.

thanks

[Michael Nash]

Flare is relative to exposure, so yes by adding more practicals you can reduce your exposure and therefore reduce the flare. Dimming or dulling the practicals reduces their exposure relative to the lens, but will also reduce the light they give to the subject. So if you dull or dim the practicals in the shot, you've got to make up that lost light from somewhere; either with off-camera light sources or even more practicals as you suggest.

 

Sometimes it's possible to dull one side of a practical (that faces the lens), so that the other side can still give light to the scene. The dulling material doesn't have to be white either; it's common to use black Streaks-n-Tips for this purpose. With a little practice you can get the right amount to dim the light output into the lens yet still have it appear whited-out on film.

 

There are other factors that contribute to visible flare, and you need to address all of them if you want to control it.

 

Different lens models and manufacturers handle flare in slightly different ways, and there are too many different lenses to list here. Maybe others can chip in with their own favorites for handling flare. As a general rule, prime lenses handle flare better than zooms because zooms have more glass elements inside to reflect the light. The shooting aperture will also give different flare characteristics, but this varies with each lens.

 

You'll also want to avoid reflections between the filter and the front element of the lens. These reflections aren't really flare per se, but part of the problem nonetheless. Shoot without a filter or use an angled filter stage. A polarizer does absolutely nothing for flare, since it cancels light waves on one axis only. A direct light in the shot is putting out waves on every axis.

 

ANY light entering the lens has flare that accompanies it; it's just that it's so far below the exposure it usually goes unseen. If you overexpose any scene enough you'll start to pick up lens flare, as you start to expose the stray light that's bouncing around inside the glass. So usually the first place to start controlling flare is to know where the threshhold of overexposure is for the lens you're using. Shoot some tests.

 

That Val Kilmer movie is called "The Salton Sea," if anyone wants to check it out.

[John Sprung]

Wow, so Streaks-n-Tips is still around. We were squirting it on light bulbs 30 years ago.

 

 

 

-- J.S.

[Michael Nash]

Wow, so Streaks-n-Tips is still around.  We were squirting it on light bulbs 30 years ago.

-- J.S.

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Yeah, I heard a nasty rumor some time back that the manufacturer was discontinuing black, leaving only brown. But I've been able to get black in expendable shops recently, so who knows...

 

Great stuff. It's a case of, "it ain't broke..."

[Guest fstop]

Roy Wagner gave a really impressive tip in one forum, and that's that the flare is actually created by the filament in the practical; by eliminating the filmanent with a tiny piece of gaffer tape or the like, the flare disappears. I tried it myself and can't say I'd argue! :)

[John Mastrogiacomo]

it's common to use black Streaks-n-Tips for this purpose. With a little practice you can get the right amount to dim the light output into the lens yet still have it appear whited-out on film.

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How safe is Streaks 'n Tips? On the can it says it is "flammable - do not use near heat or flame".

 

What is the highest wattage bulb that it can safely be used on?

 

Thanks for any information. :huh:

[Michael Nash]

How safe is Streaks 'n Tips?  On the can it says it is "flammable - do not use near heat or flame".

 

What is the highest wattage bulb that it can safely be used on?

 

Thanks for any information.  :huh:

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I think the fammability issue refers to the propellant in the can, kind of like spray paint. If you're concerned, turn the light off and let the bulb cool down before spraying (although this makes it hard to see the effect).

 

Just use common sense. If you held a lighter in front of a can of spray paint, you'd have a blowtorch. But if you spraypainted a hot surface, you'd just get cooked paint. ;)

[John Mastrogiacomo]

I think the fammability issue refers to the propellant in the can, kind of like spray paint. If you're concerned, turn the light off and let the bulb cool down before spraying (although this makes it hard to see the effect).

 

Just use common sense. If you held a lighter in front of a can of spray paint, you'd have a blowtorch. But if you spraypainted a hot surface, you'd just get cooked paint. ;)

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Thanks for the information Michael. I test a light outside first. :)