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Old November 2nd, 2011, 07:46 PM   #1
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Visual chart for f-stop differences in a frame?

So I'm doing a scene recreation for school, and I want to get as close as possible in lighting techniques... even down to the fact that "the background is has X less light on this part of the wall than this part of the wall."

And I'd really love it if someone could point me in the right direction to visually see differences in f-stops of light.
Does that make sense?

Let me try again... is there any visual chart out there that has "This is a properly exposed image... this is an image 1/2 stop under exposed... this is an image 1 stop under exposed" for a given film size/iso? (would iso make a difference?)

That way perhaps I can eyeball how much light to put on the background vs. my subjects, or other parts of the background, to get an authentic look. If it LOOKS like a half stop less light in the scene, I can make sure I light it a half stop less on the recreation set. But I'm not seasoned enough to know that "there's 1/4 less light here than there."

I've thought about creating a chart of my own, but I'll be shooting on 16mm and only have a DSLR to test with. So if I take pictures of something properly exposed, then a half step underexposed, etc., I imagine there will be a noticeable difference from what the latitude would look like on film.
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Old November 2nd, 2011, 10:47 PM   #2
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Re: Visual chart for f-stop differences in a frame?

Alex,

First, to measure the lighting in the original:
If the original scene was on film, you might try using an incident light meter at the projection screen to measure brightness in various places in the frame. Or you could use a spot meter reading of the screen.

Second, to measure the light in the scene you're shooting:
You could take spot meter readings from the camera position, or incident light readings at various places in the scene. (Or, if you could get a camcorder that has zebra stripes, you could see at what f/ stops the different areas of the wall becomes striped.)

The contrast range in the projected image would likely be a bit different than the lighting contrast in the scene, so you'd have to experiment to figure out how to translate.

However:
I'm thinking maybe the easiest thing to do is try a few different lighting setups, and see what best matches the original. (I'm assuming you don't have access to the person who set up the lights for the original scene.) I understand you will be shooting 16mm film, but it might be faster to do initial trial and error with video. The video will have somewhat different contrast characteristics than film, so the final test would have to be with film.

Looks like this might mean a lot of work. Good luck!
Ken

Last edited by Ken Hull; November 2nd, 2011 at 11:12 PM. Reason: Just realized you're shooting film, not video.
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Old November 2nd, 2011, 11:23 PM   #3
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Re: Visual chart for f-stop differences in a frame?

Thanks Ken, great suggestions. I'd be fine with trying different lighting set-ups, but if there's a part of the background that's, say, ALMOST too dark to see... I'm not going to be able to hit that line on the latitude of film just by looking at it with trial and error. Your suggestion to use video on set is probably the one I'll go with... I won't be able to do film camera tests with various set-ups, have them developed, check them out, and make changes. Metering the projected image may be a good idea, but I don't know how accurate that would be.
I was hoping to get something a little more exact, but I may have to just end up eyeballing it. Thanks a ton.

And no, I don't have access to the guy who originally set up the lights... but if you have Wally Pfister on speed dial, feel free to let him know a film student would love to have a few words with him.
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Old November 2nd, 2011, 11:24 PM   #4
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Re: Visual chart for f-stop differences in a frame?

Alex,
I realize I didn't address the subject of a chart, which you asked about. I remember Kodak made some grayscale charts that photographers would include in test shots. I don't know if that's what you meant by charts, but unless it was also in the original scene, I don't know what good it would do.

This really sounds like something that will take trial and error experiments. And of course, it would help to have lighting units similar to what was used in the original.

Ken
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Old November 3rd, 2011, 01:11 PM   #5
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Re: Visual chart for f-stop differences in a frame?

Quote:
Originally Posted by Alex Payne View Post
... but if you have Wally Pfister on speed dial, feel free to let him know a film student would love to have a few words with him.
Well, let me check..... no, sorry. I don't have him on speed dial, or even slow dial. Um.... maybe these interviews might have something. 8-)

DP/30: Inception, cinematographer Wally Pfister - YouTube

Wally Pfister gives his thoughts on cinematography - YouTube

Good luck!
Ken
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Old November 3rd, 2011, 03:15 PM   #6
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Re: Visual chart for f-stop differences in a frame?

Thanks, I've already read through tons of interviews with him but I appreciate the time and help anyway.

I've spent so long studying some of his scenes, and it drove me crazy when he talked about how his light set-ups usually take about ten or fifteen minutes. The same set-ups that would take me an hour and a half. What?? I guess that's why he has the academy award.
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Old November 3rd, 2011, 07:31 PM   #7
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Re: Visual chart for f-stop differences in a frame?

alex-

thinking of light as part of the "zone" system might be helpful.

check out this link of someone doing what you are attempting.

Capture : Cinema

be well

rob
smalltalk productions
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Old November 10th, 2011, 06:04 AM   #8
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Re: Visual chart for f-stop differences in a frame?

Quote:
Originally Posted by Alex Payne View Post
I've spent so long studying some of his scenes, and it drove me crazy when he talked about how his light set-ups usually take about ten or fifteen minutes. The same set-ups that would take me an hour and a half. What?? I guess that's why he has the academy award.
Sounds like a bit of bragging... I was an extra on MoneyBall where I spent many hours waiting for Wally Pfister to get his setups done, although to be fair this was huge scale stuff with 50 foot high diffusion panels and HMI lights strong enough to punch through the stadium lighting.
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