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Old March 7th, 2006, 09:38 PM   #16
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It sounds like you did everything right. I think any inconveniences were caused, as you said, by the studio being a bit small. Square footage costs money, and budget is always a consideration.

I'm trying to think of a way to add a kicker into the scenario. The only thing I could come up with is to use a subtle kicker with some blue gel so that you accent with the talent's blue collar. This way, you could get some more detail on the outline and differentiate the kicker by color to help reduce the risk of blending into the white background. I also think it would need to be brought further forward to cast more on the collar or side of the face than the shoulder and hair outline. Of course, I also think it is totally unnecessary, but I like to consider different variables.

From an earlier post, "Does anyone know (technically) why the background can bleed into the foreground on a shot like this? How is it possible?"

I think this is something interesting to consider. I don't know all the answers, but I think one factor may be the CCDs themselves. I'm guessing there may be a bit of bleed from one pixel to the next if some are significantly overexposed. I am also guessing that the glass has something to do with it, but I can't put words to the reason. Any ideas?
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Old March 10th, 2006, 05:26 PM   #17
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The simplified version (which is all I can do) is that each pixel can only soak up so much energy in the form of photons before they start to leak energy to the pixel next to them. This leads to "bleeding" or "blooming" especially at high-contrast edges. That results in soft edges on your talent where it looks like the background is bleeding into the foreground talent. That's the reason that you don't want to light the background any hotter than needed.
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Old March 10th, 2006, 05:40 PM   #18
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There are a lot of things that happen

First you throw a lot of light on a white background. That light will of course be reflected.

This is another light source.

That light source will create a wrap around light on the subject

In addition the light source shines directly into the lens which will cause loss of contrast due to internal reflections and can even cause flare.

It is even worse if you have white walls in the studio that then also reflect the light even more.
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Old March 10th, 2006, 07:13 PM   #19
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Thanks for the "technical" explanation. That helps me understand what not to do in the future. I never considered that information from one pixel could bleed into another.

It sounds like the best way to achieve the white-out effect, providing you don't own truck-full of lights, is to keep the white background from blowing out (or most of it from blowing out) and then make adjustments in post.
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Old March 11th, 2006, 06:27 AM   #20
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Quote:
Originally Posted by Travis Cossel
Thanks for the "technical" explanation. That helps me understand what not to do in the future. I never considered that information from one pixel could bleed into another.

It sounds like the best way to achieve the white-out effect, providing you don't own truck-full of lights, is to keep the white background from blowing out (or most of it from blowing out) and then make adjustments in post.
Travis

actual sensor bleed requires a huge overexposure. Sensors do protect themselvs from crosstalk. You get bleed for example when shooting into the sun and you know. It looks totally different. You get very strange digital artifacts because the sensor also starts to smear in the readout direction.

Blowing out a white bakcground by a stop or two will not cause a sensor to bleed or crosstalk. What you are experiencing is probably lens flare and wrap around lighting on the subject
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Old March 11th, 2006, 05:21 PM   #21
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So if I'm getting wraparound with the light from the white background, am I best served to lower the light on the background, or increase the light on the subjects and then increase the f stop on my camera?
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Old March 12th, 2006, 05:42 AM   #22
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Originally Posted by Travis Cossel
So if I'm getting wraparound with the light from the white background, am I best served to lower the light on the background, or increase the light on the subjects and then increase the f stop on my camera?
Increasing the key or fill on the subject will not help. Same goes for the f stop. If you have too much light coming from the backdrop you need to either decrease the light on the backdrop or move the subject further away from the backdrop

Try this. Turn off your lights on the backdrop. Light your subject the way you want it. Now turn on the backdrop lights and light the backdrop about 1 to 2 stops over the key light.

also make sure that the lights used to light the backdrop do not light the subject. Use barndoors or even better use black flags to flag off the light towards the subject
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Old March 13th, 2006, 11:23 AM   #23
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Quote:
Originally Posted by Michael Salzlechner
Travis

Blowing out a white bakcground by a stop or two will not cause a sensor to bleed or crosstalk. What you are experiencing is probably lens flare and wrap around lighting on the subject
No, but 4 or 5 stops might, depending on a lot of variables of course. I've seen footage where they tried to get the limbo look by simply pouring light on the background, and there were definate signs of bleeding between pixels. Without seeing this specific footage, we're guessing of course.

Regardless, the approach to fixing the problem is spot on. Light the foreground and bring the background up to a stop or two over your key.
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