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Zebra Setting. Need Advice

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Bryce Moose
Zebra Setting. Need Advice
on Nov 3, 2015 at 6:29:32 pm

I'm new the zebra setting on my camera. My camera only has two options 70 and 100 IRE. If I'm filming a landscape, building or a shot without people do I use 70 or 100? I found that trying 70 while filming a barn zebras showed up on the building but the sky was blown out. Does that matter? If the barn is fine is anyone going to care about the sky? I tried shooting it again with 100 zebras and I adjusted the exposure till there was no zebras. This time the Barn was so dark you can't see it.
What do I actually do here?
Also for people do I expose for the 70 zebras to be on the face and not care what the exposure is on the background? Or do I set it to 100 zebras for people?

I also watched a select board meeting on my local public access station and everyone was siting in front of windows which were blown out. If you are exposing for the people is it okay to have windows behind them overexposed?

Bryce


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Rick Wise
Re: Zebra Setting. Need Advice
on Nov 3, 2015 at 8:06:59 pm

Anything over 100 will be clipped -- no detail. For landscape shooting I'd use the zebras set to 100. If the barn is then too dark, you can fudge a bit, depending on the camera. A lot of DSLRs will turn that sky to magenta if significantly overexposed. So if you have one of those, protect the highlights. In post you can usually pull up the midtones (in this case the barn.)

Shooting Caucasian people I like to set the Zebras to 70, and adjust exposure until there is just a hint of zebra on the bridge of the nose and/or a small part of the forehead. Doing so should get you correct exposure, but only for Caucasians. Black skin varies enormously in darkness/lightness.

But there may be times when you want the face to be darker than "correctly" exposed, as in "moonlight." Or, if the actor is mostly in the dark, but there's a hot side light on part of his face, that side should be at least a stop hotter than "normal."

In filmmaking, there are no forumulas beyond the "inverse square law" and "west Virginia."

The best method: get an incident light meter and learn how to use it. Like the Sekonic L-308DC for around $250. It's a bit tricky setting up correctly but after that a pretty neat little pocket meter. (For shooting HD, you'd set the mode of the meter to.... HD. Etc.) After you've mastered that meter, get a Pentax digital spot meter on eBay and learn how to use it with the Zone system. When you've mastered both meters, you are beginning to control your exposures well beyond basic "correct" lighting and f/stops. Sounds too daunting? Maybe you local community college has some courses in photography. You can adapt that information to shooting video with a bit of ingenuity. Maybe it also has film classes as well, but my guess is you'll get better information about the many possibilities of exposure from the still-class. Unless you've got a really savy instructor of "film."

Rick Wise
Cinematographer
MFA/BFA Lighting and Camera Instructor Academy of Art University
San Francisco Bay Area
http://www.RickWiseDP.com


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Bryce Moose
Re: Zebra Setting. Need Advice
on Nov 3, 2015 at 10:51:07 pm

How would I apply a light meter via ISO when my Canon XA25 doesn't have an ISO setting? It only has F-Stop and Shutter

Bryce


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Rick Wise
Re: Zebra Setting. Need Advice
on Nov 3, 2015 at 11:07:49 pm

Figure out or find out in the specs what the effective, native ISO is for your camera. To figure it out, set up a Kodak gray card in soft, even light. Zoom in on the lens so that the card fills the frame. Set the camera to "auto" and read to what f/stop it adjusts. Is there a setting for variable shutter speed? If no, assume it's 2 times the frame rate. If you can adjust shutter (I think you can) then manually set it to twice the frame rate. Let's say the reading is f/5.6.

Now place the meter in the same light as the gray card. Set the shutter speed to 48 if you are shooting at 24 fps, or 60 if you are shooting at 30 fps. Begin with ISO 400. Now take a reading. If the f/stop turns out to be f/5.6 you have found your native ISO for this camera. If the f/stop is f/8, re-set the ISO to 200, and you'll get 5.6. Etc. Note: ISO changes in 1/3 of a stop increments and it is likely you will need to make smaller than whole f/stop adjustments.

You may find your camera has a different ISO for daylight vs. for tungsten lights, so repeat the experiment in each situation to determine native ISO.

Rick Wise
Cinematographer
MFA/BFA Lighting and Camera Instructor Academy of Art University
San Francisco Bay Area
http://www.RickWiseDP.com


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Bryce Moose
Re: Zebra Setting. Need Advice
on Nov 4, 2015 at 12:58:40 am

How would I use the zebras in a concert setting? Do I set to 100 and make sure no zebras show up or do I set to 70 and expose for some Zebras on the face of one band member? The lights on stage constantly change.

Bryce


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Rick Wise
Re: Zebra Setting. Need Advice
on Nov 4, 2015 at 3:20:56 am

Tough one. With the lights constantly changing. Any way to go in early and have the guy running the lights show you the max he'll do? In that case, set you zebras to 100 and adjust f/stop so that there's a small quantity of zebras showing. Stick anybody out in the light to judge. In post you may need to ride the mid tones up or down to compensate if things get too dark and then bright again.

If you can't do that, I'm at a loss. The worst solution would be to set the camera to "auto" because it will ramp exposure up and down with the light changes, always too slow and artistically wrong.

Rick Wise
Cinematographer
MFA/BFA Lighting and Camera Instructor Academy of Art University
San Francisco Bay Area
http://www.RickWiseDP.com


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Bryce Moose
Re: Zebra Setting. Need Advice
on Nov 4, 2015 at 2:14:47 pm
Last Edited By Bryce Moose on Nov 4, 2015 at 2:15:11 pm

Okay thanks,

I am curious to know if Lights and solid whites are supposed to be at 100 or if they can peak above 100?

Here is a screenshot from a music video. The lights are wicked bright. Do those exceed 100? Whenever I adjust my camera so no zebras show up on lights the rest of the image is dark.

https://watchusplaygames.files.wordpress.com/2012/05/miseration-dreamdeciph...

Bryce


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Todd Terry
Re: Zebra Setting. Need Advice
on Nov 4, 2015 at 3:37:57 pm

Those blown-out whites of the backlights are above 100%. If the blown-out look (absolutely pure white, no detail whatsoever) look is ok or artistically what you want... then going over 100 is ok.

Just remember there is NO detail in anything over 100 though... it's completely solid white, and you can't get it back should you change your mind... so as long as you are sure about that and that's the look you are after, it's ok.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com



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