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Canon XH Series HDV Camcorders
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Old May 2nd, 2007, 02:35 PM   #1
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How To Use/Read Zebra Exposure...

Hello,

I am a "rookie" videographer and I just started using my XH-a1. I was hoping that someone could shed some light (no pun intended) on the proper way to read/understand the zebra exposure lines on the LCD/View finder. Basically, I'm looking for a brief tutorial on how to use these to improve the quality of my footage.

A few of my questions:

What should I be looking for when using the zebra marks?

I.E. When taping a sunrise, Should the sun be covered in Zebra marks while the foreground, etc. is not?

When shooting someone's face, should you open the iris until you see zebra marks on their face and then back down a bit?

What should the setting be for the Zebra pattern? Mine is currently at 85.

Any information you guys are willing to provide would be greatly appreciated.

Thanks,

Jerry
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Old May 2nd, 2007, 03:02 PM   #2
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Check this thread for some informative discussion.
http://dvinfo.net/conf/showthread.php?t=70332

Zebra is often used to identify the point at which highlights of interest are at the verge of becoming overexposed/blown out/losing detail. You adjust exposure to have the brightest highlight in which you want good detail just into zebra. (That apprach of course assumes shadow detail is a secondary concern given that you would be exposing for highlights.)

Bottom line is experiment to judge the effects and results and then use what works for you.
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Old May 2nd, 2007, 08:05 PM   #3
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http://www.greatdv.com/cameras/Zebra.htm
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Old May 3rd, 2007, 07:41 AM   #4
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I take issue with the common belief that skin tone is at 70 (the above article claims 80...ouch) and I've found MOST skin tones of caucasians falls around 55 to 60 IRE. Whoever picked these numbers must have used a very pale person.
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Old May 3rd, 2007, 08:26 AM   #5
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curious, does teh A1 have a peaking level meter as found in the DVX100 or is it strictly zebras? ie, can i turn zebras off, an duse a numeric value? in turn, allowing thw LCD to respond to the luminance as per natural occurance (without those zebras being visible in the frame?
I found using numbers and the LCD/evf to be a little more accurate in regard to "seeing what your shooting"
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Old May 5th, 2007, 10:17 AM   #6
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Peaking is only for focus assist, zebras for levels...but I prefer the exposure "bar" (wide shallow rectangle with dot that moves left to right, center being proper exposure according to the cam) since you can't have peaking and zebras at the same time. The bar is extremely useful and I use it all the time.
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Old May 5th, 2007, 10:35 AM   #7
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Do you find the exposure bar reliable?

I used to use it, but even when its dead centred, the exposure does not seem correct sometimes. I'm not sure how the A1 reads the exposure levels though.
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Old May 5th, 2007, 11:08 AM   #8
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Auto exposure systems are typically based on a weighted average analysis of multiple points or zones in the image, and they are engineered for typical image composition and content. (The XL1 use ~49 zones with lower center weighting). When the image content departs from the "typical' content/composition the auto exposure is fooled and the results may not be close to correct or what you would like. That is why many folks use a calibrated monitor to judge exposure. As you gain experience with the camcorder and its exposure aids, you will get a better feel for how they deal with unusual inage conditions an be better able to use these the aids to set up the shot.
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Old May 5th, 2007, 11:57 AM   #9
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Jerry,
There is excellent advice and comments in the thread referenced above.

I use zebras set to 90 for shooting outdoor scenics making sure no major parts of the picture show lines. This usually gives me an excellent picture overall ( sometimes I'll tweak this a little one way or the other)

For interviews or people I set zebras to 70 making sure they just disappear on the highlight side of the face. I usually try to keep the back ground within some reasonable exposure above or below the skin. (I do this by referencing the little exposure bar at the top of the A1 and moving the apeture dial up and down a bit to see where the zebras appear/disapear) This takes a little practice. You can also uses zebras set to 90 - 100 just to check for your reference. If the background is too blown out it will bloom into the face ruining the shot. So keep the background in check.

As mentioned, this is just the procedure I use. I often break my own guidelines to get a different look. Learn to use this tool and it will be a godsend to you. Best of luck.
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Old May 5th, 2007, 12:31 PM   #10
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Quote:
Originally Posted by Chan Ee Jien View Post
Do you find the exposure bar reliable?
I find it helps to pan around to see where the dot moves....you can get an idea of the range of values in your scene and pick the appropriate point (usually I try to meter the area I'm trying to focus on and let highlights blow out if I need to)
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Old November 21st, 2011, 12:13 PM   #11
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Re: How To Use/Read Zebra Exposure...

Here’s how I use Zebra patterns on my DVX100A:
1. I go to Scene File/Display Settings/Zebra
2. I set Zebra 1 to 80% (for normal highlights)
3. I set Zebra 2 to 105% (for blown out highlight indicator)
4. I point the camera at the scene and press the Zebra button on the camera side panel to see the Zebra 1 indicator.
5. I open the Iris until I see the lines on the “normal highlight” areas, then switch to Zebra 2. If I see only a few lines in the scene at Zebra 2, that’s a pretty good Zebra exposure reading.

Of course, it all depends on what you’re trying to do with the scene.
For example, I have an Apple on my desk that has really nice light on it and a plastic wrapper nearby reflecting some bright highlight spots. If I point my camera at it with the above camera settings, Zebra 1 shows lines on the Apple, but not the wrapper highlights. Zebra 2 shows lines on the wrapper highlight spots but not the Apple. The wrapper highlights are rather small, so that’s a pretty good Zebra exposure reading.
If I wanted to show more background, I’d have to adjust the lights and then take another reading.
That’s my 2 cents
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Old November 27th, 2011, 03:58 AM   #12
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Re: How To Use/Read Zebra Exposure...

Yrs ago a TV news camera shooter told me .. outdoors, expose the clouds till you see their detail then you've got it.

Cheers.
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Old November 30th, 2011, 10:50 AM   #13
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Re: How To Use/Read Zebra Exposure...

I set my zebras for 100 and leave them there. To me, knowing that something might be blown out doesn't really help me. I want to know what parts of the image, if any, are actually clipping. If the zebras are at 90% I might be blowing part of it out, but I might not.

I prefer to take the guesswork out and have it tell me when I'm actually clipping part of the image. Works well for me.
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