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Old April 14th, 2009, 01:38 AM   #1
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Importanct of a Light Meter

I am shooting a short on a HVRV1U. I will use FCP to desaturate the final image. I was just wondering two things.

1. Do I have to worry about light temperature or the type of light's I am using if the final cut will be black and white? I have shot about one third of the movie and it looked good once I added the affect in FCP regardless of the lights I used. (Florescent and Incandescent bulbs). It looks like I am getting whiter highlights on my images canvas when I paint with Florescent.

2. How important is it for me to use a light meter to set the f-stop of the camera? I have used it on Super 16 but how important is it in the digital medium? If so, what "budget" light meter do you recommend.

Any other words of wisdom concerning black and white and the effect light has on it.

Thank you
dMd
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Old April 14th, 2009, 03:00 AM   #2
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Desaturation of your colour image should leave you with the full scale of b&w tones but you raise an interesting point - about how the b&w looks when desaturating differently white balanced original footage. I think you need to shoot a very short colour bar test chart at different K levels, desaturate them both and take a closer look.

Incident light meters are good because they ignore distractingly lit (or unlit) backgrounds and so on, but reflected light meters are no better for video than the reflected light meter already built into your camcorder. In fact I'd go so far as to say the inbuilt one is the better of the two as it can show (via zebras) dangerous hi-lite areas. They also take into account the inbuilt ND absorption and lens ramping.

Of course as with every reflected lightmeter reading, you have to know how to interpret the results. The 18% gray set-up is technically excellent but often artistically suspect.

tom.
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Old April 14th, 2009, 05:02 AM   #3
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The incident light meter that is standard for shooting Super 16 is fine. It's best used to balance your lighting having discovered the effective ASA of your camera. I'd then use the camera's zebras (or use the waveform) combined with a monitor to set the actual stop, these video camera zoom lens tend to have a lot of ramping.
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Old April 14th, 2009, 05:58 PM   #4
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The great thing about digital imaging is that what you see is what you get.

With film incident and reflective meters were indispensible because they allowed an accurate prediction of exposure. I used to shoot critical color on 4x5-inch plates and also shot zone system in black-and-white. Couldn't do it without accurate meters.

But with digital filmmaking you can see what you're getting right off the monitor. You'll know immediately if something looks relatively too dark or too light. Or if you're clipping highlights. Or if your shadows lack sufficient detail.

Zebras provide lots of good exposure info and can also provide a warning against clipping.

Just need to make sure that you get everything you need in your scene's tonal range, then fine-tune the look in post.
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Old April 15th, 2009, 11:24 AM   #5
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In addition to zebras, the V1U also has a histogram display which I've found *very* useful. It will quickly tell you if you're in danger of clipping the whites or crushing the blacks.

Highly recommended! Get familiar with what the zebras and histogram are telling you.

To use the lcd/viewfinder as Dean recommends, set it up right. If it is too bright or too dark it will be misinforming you about exposure. Turn on the camera's color bars, and adjust the brightness so that the 10% grey bar is just distinguishable from black.

See this image, which enlarges the lower right corner of the colorbars.
http://www.dvinfo.net/conf/attachmen...night-bars.jpg
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Old April 17th, 2009, 12:00 PM   #6
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Quote:
Originally Posted by Seth Bloombaum View Post
To use the lcd/viewfinder as Dean recommends, set it up right. If it is too bright or too dark it will be misinforming you about exposure. Turn on the camera's color bars, and adjust the brightness so that the 10% grey bar is just distinguishable from black.
Seth is right. Keep in mind though that LCD panels and CRTs (some of us are still using CRT TVs...) have VERY different gamma response curves, especially in the darker greys. In my experience consumer LCDs and the LCDs on camcorders have SIGNIFICANTLY less response in dark greys, biasing my exposure poorly. Larger and/or professional LCD panels do significantly better than the 2.5 - 3.5" LCDs most of us have on our cameras.
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Old April 19th, 2009, 05:11 PM   #7
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Thank you all. Just another follow question up if anyone gets the chance - -

- - When you say white and black clipping I understand that is for broadcast but sometimes I like the dramatic juxtaposition of extreme shadows and burning white light. If a portion of my scene is zebra'd what does that exactly mean when I output the final video? Will the white's be absolute white and the black be as black as digital video allows it?

I hope this is worded properly. Again thanks to all who replied, this forum and practical learning is teaching me more than my four years of college.

dMd
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Old April 19th, 2009, 05:30 PM   #8
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While you might like the look of extreme contrast, I would strongly recommend capturing as much dynamic range as you can, THEN crushing blacks or clipping whites in post.

If you clip whites or crush blacks in-camera, they're gone forever. There's no fixing it if you decide to give it a different look later.

You would need a great deal of time getting exactly what you want during production. Time is money and you will spend a lot of it, plus possibly wearing the patience of your talent and crew very thin. Even then chances are you won't get it perfectly right without making adjustments in post. For one thing the monitor you're using during production won't be properly calibrated nor viewed under optimal conditions. So any judgments made in the field might not look right when you get it into a properly controlled viewing environment.

And you'll still have to have consistency from one shot to the next. That's something else that's better fine-tuned in post than on the set.
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