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Old August 30th, 2009, 04:43 PM   #1
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zebras at 70%. . .for what?

So, conventional wisdom has it that skin tones expose correctly when they read at 70% on a waveform monitor. Hence, setting one's zebras to 70% (if you can), should allow you, when you only have a viewfinder (i.e. no on set monitor), to set correct skin tone exposure.

The thing is. . .exactly WHAT components of the skin tones should be at 70%? Highlights? Midrange? Say, for instance you're in a room lit with overhead flo lights. Chances are, you're going two have to main exposure levels on a person's face. . .you'll have hotter areas on the forehead and nose, and the rest will be a little darker. So, which of these would you want at 70%?
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Old August 30th, 2009, 05:20 PM   #2
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It's an imprecise and unsatisfactory science! I'd say you want to get rid of zebras on highlights, unless they're really bright.
These days I only use zebras at 95-100% for whites.
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Old August 30th, 2009, 05:41 PM   #3
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I think it's a fairly common camera guy thing to have at least one of your zebras (some cams have two different patterns that can be displayed simulaneously) set at 70.

A camera I use a lot doesn't go past 90, which doesn't help me. Personally, I am used to, from my own cams (XL1s and XL2) setting them to 100, and stopping down from there, and eyeballing it. I can pretty much always nail exposure that way. For some reason it's harder in B&W (like a pro cam's viewfinder), and as I said, a client's cam I use a lot doesn't let you set them past 90.
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Old August 31st, 2009, 10:20 AM   #4
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I had read years ago that Caucasians set at 80% and African-Americans at 70%. Usually when I'm doing an interview shoot I start there and then tweak depending on the person, clothes, background, etc. On my field cameras for work, DV200s, I have the zebra bars set at 80% and 100%. When doing a quick lecture I usually have my crew zoom in on the face, iris down so the zebras just go away and then adjust or tweak from there. It usually gives me good results.
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Old August 31st, 2009, 10:28 AM   #5
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If I only have 70 IRE for zebra (and NOT 75), on the highlight side of caucasian skin tone I let zebra show on MOST of the highlight. For 75IRE on caucasian skin tone, I allow just ribbons at cheeks and foreheads (assuming light source just above subject).

Steve's discussion of 95-100 IRE zebras is valid IF you are looking to get maximum dynamic range out of an image for 3 way colour correction in post. For direct playback to broadcast, your image needs to be properly exposed for subject AS WELL AS not blowing out your whites. Ideally, I like to have two zebra patterns going on broadcast cameras: 75IRE for skin highlights and 102IRE for blown out whites. (I don't want to see 100 IRE zebra - too much going on in the viewfinder - I have a LOT of info in there already).
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Old August 31st, 2009, 10:34 AM   #6
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It's funny how we all have different methods for getting proper exposure. Here is my take:

If I'm shooting objects or landscapes then I'll set my zebras to 100% to protect my highlights/skys/whatever I'm trying not to blow out.

If I'm shooting people as my main subject I'll set my zebras to 70% expose for skin then drop it half a stop or so since to my eye 70% on Caucasians is too bright. I prefer Caucasians down around 60% myself. For darker skinned people I'll get my 70% zebras and crank it down another 1 or 2 stops depending on how dark they are. When shooting people I tend to expose for my subject and let the highlights go where they may. Of course not every situation and setting is ideal for this method and all rules can be bent or outright broken depending on what you're trying to achieve, but that's generally my default.

I do miss shooting with cameras that would allow you to see both 70% and 100% at the same time and there are also times where I miss a nice sharp black and white full sized viewfinder.
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Old August 31st, 2009, 03:15 PM   #7
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there are also times where I miss a nice sharp black and white full sized viewfinder.
AMEN! Focus is SOOOO much easier on a true black and white CRT.
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Old August 31st, 2009, 09:22 PM   #8
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I've tried zebras at 100 and at 70, and the latter seems more useful to me. At least in events where you mostly don't have control over the general lighting and are almost always exposing for faces. Highlight are often blown in this situation, and I don't need zebras at 100 to tell me that. They're just annoying for nothing.

That being said, I find as time goes by, and I get used to my camera's lcd, I use zebras less and less. Turn them on for a quick check when I'm not sure, but mostly eyeball it. I'm much more interested in peaking for focus, and my camera won't do both at the same time.
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Old August 31st, 2009, 10:29 PM   #9
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Wow. Didn't realize this was such a can of worms. It's like I'm a forum troll.

I like Zebras. Here's why.


I can nail exposure pretty well by eye with my XL2 viewfinder. Yes, the XL2 viewfinder, using my method of setting the "zeebs" at 100 and just eyeballing from there. HOWEVER, I have had instances where for some unknown reason, zeebs were OFF, not intentionally, and it has COMPLETELY screwed my judgment. Shooting stuff outside with no zebras, I once overexposed almost everything. For me they make a world of difference. When you're outdoors, and you turn on your cam, and look into the EVF, and see stripes on everything, you start closing down/engaging ND filters 'til they go away, and you're then at least in the ballpark. That's how I like it.
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Old September 1st, 2009, 07:55 AM   #10
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Wow. Didn't realize this was such a can of worms. It's like I'm a forum troll.
It's not really a can of worms. Zebras are just a tool, and it's up to the operator to decide how, or even if the tool is useful. There are lots of ways to use zebras and you'll never get a consensus that one way is the 'right way.' It depends on too many factors.
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Old September 1st, 2009, 09:02 AM   #11
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It's not really a can of worms. Zebras are just a tool, and it's up to the operator to decide how, or even if the tool is useful. There are lots of ways to use zebras and you'll never get a consensus that one way is the 'right way.' It depends on too many factors.
They're a tool that needs to be used with care. 70% on a skin highlight usually works (forehead etc), although not if the subject has a tan. A correctly set up B & W CTR V/F is much more useful than most LCDs in making these judgement calls. It also depends on the lighting/exposure effect you're trying to create.
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Old September 1st, 2009, 11:07 AM   #12
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A correctly set up B & W CTR V/F is much more useful than most LCDs in making these judgement calls.
Agreed. In a properly set up B&W CRT viewfinder, if an image looks good in terms of contrast and exposure, it should look fine in colour. In my experience, colour is far more forgiving than a B&W CRT viewfinder. Having said that, the main reason we can get away from heavy brick batteries that only give us 2 hours of run time is due almost exclusively to the "abolishment" of CRT viewfinders in all but the higher end broadcast shoulder cams... CRT viewfinders look good but they are massive energy pigs.
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Old September 1st, 2009, 12:48 PM   #13
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If 85IRE is the level where the highlights of an average caucasian skintone normally are, then your zebra threshold should also be set to 85%. Then first tiny strips on either chicks, nose or forehead will tell you where to stop opening your iris right away.

70% zebra setting is too low imo. 70% means the whole face will be covered with zebra strips which is too annoying, makes it hard to focus, etc
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Old September 1st, 2009, 01:51 PM   #14
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If 85IRE is the level where the highlights of an average caucasian skintone normally are, then your zebra threshold should also be set to 85%. Then first tiny strips on either chicks, nose or forehead will tell you where to stop opening your iris right away.

70% zebra setting is too low imo. 70% means the whole face will be covered with zebra strips which is too annoying, makes it hard to focus, etc
I usually only use it for a forehead and perhaps a bit of cheek, not the brightest highlight spot. For a light skinned person it can cover the most of the face, but I usually just use the zebra as quick confirmation and usually switch it off anyway. Not all faces are the same, so I don't get locked into being dogmatic about using a set level on all faces, it's more what looks right.

Personally, I find a full zebra face coverage a bit flat looking and bland.
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Old September 1st, 2009, 03:33 PM   #15
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I'm KIND OF with Stas: I feel 70% is too low for highlights (70IRE should be entire keylit side IMHO, which makes for a very busy viewfinder) but 85IRE is WAY too hot for highlights (again, IMHO). 75 for highlights (as mentioned above) is my "magic number" for NORMAL visuals - completely disregard if I'm going for a "look" or trying to approximate real world lighting in pieces where verité is important.
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