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Old February 9th, 2005, 11:09 PM   #1
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Confused about Zebra Exposure

Ok I have been having problems lately with overexposing my shots. So I decided to learn this zebra technique but am a little confused. Now I have looked into it a ways and still don't understand really. I have the zebra level set to 85...i think I heard 100 is the highest it can go legally but is 85 itself too high? Next, so i turn the camera on, and there i am with all these stripes, do i turn exposure up/down until there are no more stripes or what? Thanks for the help in advance.
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Old February 9th, 2005, 11:22 PM   #2
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The stripes are visible on the areas of you image that are equal to or above the Zebra setting. I.E. if you set your zebra level to 85, any part of your image that is above 85 will have stripes on it.
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Old February 9th, 2005, 11:41 PM   #3
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Josh,
For clarity's sake I'll take the liberty to slightly edit Jesse's first sentence:
Quote:
The stripes are visible on the areas of you[r] image whose exposure values are equal to or above the Zebra threshold setting.
The Zebra display is merely a tool to enable the photographer (videographer) to better judge the exposure of a scene. Video has a relatively narrow range of exposure tolerance relative to, say, films. Areas that become over-exposed are often said to be "blown-out" and their detail contents are irretrievably lost.

Unfortunately the human eye is easily fooled by colors and contrasts in a scene, particularly when viewing it through a teeny, low-resolution viewfinder or a teeny onboard lcd screen. Thus, the zebra display option is meant to help offset those sensory and technical shortcomings by providing an unmistakable overlay showing areas that are either blown-out or are at / above the exposure threshold you've specified for the zebra display. It's also worth noting that zebra displays are mainly useful only for shooting in manual exposure control mode. The program modes place exposure...well...out of your control.

The level at which you set your zebra display is generally determined by the nature of the subject you're shooting. In general, setting it to 100% tends to be less useful than to, say, 90%. But level selection is a personal preference.

The best way to learn to use the zebra display (and nearly every other camera feature) is to experiment. Shoot footage with bright areas, set the zebra to different levels and adjust your exposure to eliminate the pattern. Then review the clips and the notes you took for each clip.
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Old February 10th, 2005, 12:21 AM   #4
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Well I shoot in manual mode so that isn't a problem. I have been doing a lilttle bit of experimenting in the last hour or so and I think I'm getitng the hang of it....thanks for your guy's help.
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Old February 10th, 2005, 05:37 AM   #5
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I had mine (on my XL1S) set to 90. So I first exposed with lots of
zebra strips and then tuned it down till I saw no or just a bunch
of lines (depending how the rest of the scene's contrast looks,
this is where black level zebra would be nice to have as well).

Keep in mind that a scene can have a too large exposure range
(usually with bright lights or the sun etc.) for your camera to
capture and you have to make a choice to:

- change the camera angle / position
- over or under expose some part(s)
- add a grad ND filter to add ND filtering to the areas that are too hot
- add production gear (tents, scrims, flags, nets, tents etc.) to reduce hot spots etc.
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Old February 13th, 2005, 11:24 PM   #6
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More experienced shooters can expound further on this, I'm sure, but it is my understanding that zebra stripes are not just about over exposure, but also about optimal exposure of key elements in the frame.

For example, if you set your zebra to 85 percent, it's not the end of the world if there are stripes in the brighter portions of the frame - especially in a high contrast shot. But you will probably want to make sure there are no stripes on a person's skin. You choose your skin level, then adjust exposure until it is just a click below causing stripes on skin.

I have heard some shooters complain that they think the 85 percent limit on the XL 2 is too high. They prefer to set a 75 or 80 percent zebra, specifically for locating optimum exposure level for caucasian skin.

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Old February 14th, 2005, 01:25 AM   #7
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Vence -
You absolutely right there.
You have to learn to interpret what the stripes are showing you. I know some cameramen who have their zebras set to 70%, which shows stripes over most of the image - something I don't like at all. I tend to run mine at 90%, but I know how to read them. Also, I will always tend to underexpose a tad... ( a small tad!)

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Old February 15th, 2005, 03:09 AM   #8
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I have been using the theory (in practice) to expose so that the zebra will only be shown on a face (forehead spot) and it has been OK so far. So, over-expose so you get rid of the zebra and close step by step.

Works for me but as everyone has said it needs practice and more practice so "you" are happy with the results.
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Old February 15th, 2005, 06:42 AM   #9
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And Alan, you set your Zebras at?

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Old February 15th, 2005, 08:09 AM   #10
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I keep zebra percentage at 100% and underexpose till they dissapear, depending on shot. Works fine for me. Try to experiment a bit.
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Old February 16th, 2005, 09:43 AM   #11
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I'm coming to this from stills photography but it seems worth noting that zebras are for highlights and there is no aid for shadows which (in decent daylight), will have to be compromised to some degree in order to retail all highlights (ie get rid of all zebras). So, obsessively getting rid of all zebras may result in shadow detail blacking up.

While perusing some production guidelines for tv i notice frequent warnings about blacking up being unacceptable but few about highlights burning out.

Highlights treatment does seem to be a matter of taste whereas bad shadows are just 'wrong' (generalisation).
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Old February 16th, 2005, 11:03 AM   #12
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I almost always have the zebra stripes turned on. Mostly I shoot concerts/performances. It is a reasonable rule of thumb to keep good exposure on people's faces - the human visual system is fine-tuned for recognition of facial features. If the shirt the performer is wearing is a little blown-out - it's not a disaster, but when a person's forehead is lost in a sea of white with no detail, then it's a problem.
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