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Old June 19th, 2008, 01:44 PM   #1
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Zebra (at 75) on face to set exposure...

Does anyone here use the zebra lines set at 75 to set exposure on someone's face? One time I was taught by a camera man at FOX to set and use Zebra at 75 and when you see small blotches of zebra on the high cheeks and forehead... you know you're exposure is spot on.

Problem is, I vaguely remember the precise amount of Zebra that was present on the face when he showed me. Does anyone use this technique? And if so, do you have a guideline as to how much zebra you like to see on the face to know exposure is spot on?

Thanks for any help or guidance!
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Old June 19th, 2008, 02:27 PM   #2
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Setting Zebra at 75% is hard to focus, when you see zebra on the faces it is harder to tell if the faces is in focus or not, I set my zebra at 100%, adjust until you see zebra and then back down until you don't see it anymore on the faces then it is right plus since there are no zebra on the faces you can focus.
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Old June 19th, 2008, 03:23 PM   #3
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Douglas Spotted Eagle disagrees

In his Vaast DVD on the XH-A1 he suggests setting your zebra at 70%.
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Old June 19th, 2008, 03:51 PM   #4
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Originally Posted by Greg Clark View Post
In his Vaast DVD on the XH-A1 he suggests setting your zebra at 70%.
But if you set it to 70%... did he say what to look for? I mean, any Zebra would work if you knew exactly what to look for. Thanks!
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Old June 19th, 2008, 07:13 PM   #5
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I use 75%, get zebras on the key side of caucasian flesh tones and you're in the ballpark. If you use 100% you want zebras on white things, like paper, otherwise you'll be overexposed.
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Old June 19th, 2008, 11:17 PM   #6
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Excellent answer

Your explanation Bill provides clarity on why to keep away from 100% ZEBRA. Thanks.
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Old June 20th, 2008, 07:41 AM   #7
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Originally Posted by Bill Pryor View Post
I use 75%, get zebras on the key side of caucasian flesh tones and you're in the ballpark. If you use 100% you want zebras on white things, like paper, otherwise you'll be overexposed.
Hey Bill, any chance you could attempt to explain "how much" zebra I should be looking for on the key side of the face? I'm really trying to learn and set exposure accurately and get good with using these functions correctly. Thanks so much for your help!
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Old June 20th, 2008, 07:59 AM   #8
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If using 75 IRE, look for "ribbons" (very thin lines) ONLY on the highlights of the key side (for example, the TOPS of the cheek bones on caucasian skin tone). If using 70 IRE, look for the entire key side to be affected by the zebra pattern. Of course, this is just a guideline for "normal" exposure of caucasian skin tone and doesn't take into consideration "mood" or non-caucasian skin tones.

If shooting persons of particularly dark skin tone, look for ribbons of zebra at 75 IRE on highly reflective parts of the skin (athletes - sweat, for example) and realize you may need to "bump up" exposure or correct in post to ensure a full compliment of detail in faces. Or throw a bit more light into the mix if conducting a formal interview.
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Old June 20th, 2008, 08:03 AM   #9
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Quote:
Originally Posted by Khoi Pham View Post
Setting Zebra at 75% is hard to focus, when you see zebra on the faces it is harder to tell if the faces is in focus or not, I set my zebra at 100%, adjust until you see zebra and then back down until you don't see it anymore on the faces then it is right plus since there are no zebra on the faces you can focus.
I have one of my custom keys set to zebra (at whatever % I want). Then I can quickly turn it on and off for focus.
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Old June 20th, 2008, 08:17 AM   #10
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Hey Shaun, Thanks for trying to explain what I should be looking for on the face in regards to 75 IRE zebra lines.

One thing I've noticed when using this technique, is that the slightest shifts in aperture causes a lot of zebra to either appear or dissapear from the face.

I thought I'd try posting a picture of what I have been setting exposure at with 75 IRE zebra. It's just an example... but this is a good ballpark of the amount of zebra I like to see when I know my exposure is spot on.

What do you think? Do you think this looks right to you guys? Have a look (I've attached a picture to this post):
Attached Thumbnails
Zebra (at 75) on face to set exposure...-zebra-face.jpg  
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Old June 20th, 2008, 09:53 AM   #11
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That's a pretty good ballpark. It depends on the lighting, really. For example, when I shoot a documentary type interview where I want a dramatic look, I'll use a broad, softlight positioned well to the side of the face so the opposite side is totally shadowed, then fill that as necessary. In that situation the key side will be almost all zebra'd.

Keep in mind the zebras are nothing more than a method of reading a reflective light meter. Instead of numbers, you get a little picture of where the light is. And like any meter, it's a guide. You may have to open up or stop down a little as the situation warrants.
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Old June 23rd, 2008, 08:19 AM   #12
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Perhaps a stupid remark, but in photography, I use a light metering system wich give me the exact speed and F-stop. Doesn't this excists for video ?
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Old June 24th, 2008, 01:48 AM   #13
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You certainly could use an incident light meter after making series of calibration shots to find out what the ISO speed of the camera used at each gain, gamma etc. setting is.

But as the viewfinder, and even better an external monitor and scopes (like in DVRack, Canon Console etc), can be used to more or less exactly show what the picture actually looks like, and zebras can be used to catch overexposure, very few people go that route. Take a light meter reading, set the exposure, then make slight corrections with the monitor, or just adjust the exposure without the meter, where is the real difference? Two steps less without the meter...

When setting up lights an incident light meter cam be usefull for determining the fill-in ratios and such.
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Old June 25th, 2008, 01:30 PM   #14
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Originally Posted by Erwin Vanderhoydonks View Post
Perhaps a stupid remark, but in photography, I use a light metering system wich give me the exact speed and F-stop. Doesn't this excists for video ?
In photography, with the exception of colour positives (slides) we have ALWAYS had a secondary stage (either printing or digital manipulation) with which to "correct" our exposure, easily within a latitude of two stops either way. In colour positive film, we tend to "bracket" our exposures to make sure we are "bang on". We don't have the luxury of "bracketing" video in real life scenarios but we can do extensive post production to correct video for non-live broadcast, but this is off course time consuming and not always practical (news, live footage).

Deke: And yes, that image looks more or less properly exposed. And that is where I would expect to see zebra with either fluorescent ceiling lights or a "toppy" lighting configuration. As well, I would expect zebra on the top of the nose as well.
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Last edited by Shaun Roemich; June 25th, 2008 at 01:31 PM. Reason: Fumbly fingers make for grammatical errors
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