zebra bars at DVinfo.net

October 31st, 2002, 04:50 PM

I have a GL2 that offers zebras. Can anyone tell me where I can get a detailed description or tutorial of the finer points of using this expoure guide?
thanks
robert

Jay Gladwell · October 31st, 2002, 05:00 PM

Robert--

Check out this link, it should be of some help to you.

http://www.greatdv.com/cameras/Zebra.htm

Ken Tanaka · October 31st, 2002, 06:12 PM

Nice link! Note, however, that the GL-2's zebra system offers only a low-threshold display. That is, while its display is adjustable (ex: 90IRE) it does not vanish at values above the threshold as the "70-90" setting discussed in this article does. It only vanishes when brightnesses fall below the threshold.

Dave Grey · November 1st, 2002, 08:15 AM

<<<-- Originally posted by Ken Tanaka : Nice link! Note, however, that the GL-2's zebra system offers only a low-threshold display. [...] It only vanishes when brightnesses fall below the threshold. -->>>

Is it a reasonable approach to use the (GL2) zebra to get correct facial highlights by setting the level to, say, 85 then adjusting exposure untill they dissappear, in a method similar to that described for the 100 IRE setting?

And a related question-

I keep the zebra set at 100 and generally follow the method described in the greatdv article of adjusting exposure untill they (mostly) dissapear. In order to sufficiently expose the subject in some situations, small higlights are often still zebra'ed. Is this normal/acceptable, or should I be avoiding any part of my image hitting these levels?

lyd

Bill Ravens · November 1st, 2002, 08:28 AM

<<<-- Originally posted by lydanynom :
Is it a reasonable approach to use the (GL2) zebra to get correct facial highlights by setting the level to, say, 85 then adjusting exposure untill they dissappear, in a method similar to that described for the 100 IRE setting?

And a related question-

I keep the zebra set at 100 and generally follow the method described in the greatdv article of adjusting exposure untill they (mostly) dissapear. In order to sufficiently expose the subject in some situations, small higlights are often still zebra'ed. Is this normal/acceptable, or should I be avoiding any part of my image hitting these levels?

lyd -->>>

yes, and it is worthwhile to mention that any method you get familiar with...that gives you predictable results...is a method worthy of being used. I would suggest not bouncing around to a dozen different ways of finding exposure until you're well familiar with the results of one.

Jay Gladwell · November 1st, 2002, 08:40 AM

I second Bill's advice. I'd would add to that: Take some time and shoot some tests. Don't forget--like it or not--you must keep notes, because you won't remember the settings for each test.

Look at the footage you've shot, take note of which shot best suits YOUR taste/needs/requirements, and use that as your constant (referring to the IRE setting and use of zebra pattern).

Based on the above, I have always been able to get consistant results every time I shoot.

Dave Grey · November 1st, 2002, 08:45 AM

<<<-- Originally posted by lydanynom :
[...]
And a related question-
I keep the zebra set at 100 [...] in some situations, small higlights are often still zebra'ed. Is this normal/acceptable, or should I be avoiding any part of my image hitting these levels?-->>>

<<<-- Originally posted by Bill Ravens :
yes, and it is worthwhile to mention that any method you get familiar with...that gives you predictable results...is a method worthy of being used. I would suggest not bouncing around to a dozen different ways of finding exposure until you're well familiar with the results of one. -->>>

Bill, thanks for the response. I agree that sticking with one method is the way to go, for me, for now. I'm not clear on what your "yes" means relative to my second question (quoted again above). Would you mind clarifying?

Thanks again.

lyd

Bill Ravens · November 1st, 2002, 08:50 AM

yes, means that setting the zebra to expose for skin tones is something done quite often by "Hollywood" videographers. I beleive the convention is to use 70IRE for the HIGHLIGHTS in caucasion skin....ie nose, forehead. A setting of 80 IRE will slightly overexpose the highlights...not really something you want to do with DV exposures. Those little areas of zebra that are "remnants" are merely indications of the contrast found in everyday scenes. The only effective way to get rid of them is to bring lighting hardware with you when you shoot and to place the lights appropriately to reduce the overall scene contrast.

Dave Grey · November 1st, 2002, 09:04 AM

<<<-- Originally posted by Bill Ravens : [...] Those little areas of zebra that are "remnants" are merely indications of the contrast found in everyday scenes. The only effective way to get rid of them is to bring lighting hardware with you when you shoot and to place the lights appropriately to reduce the overall scene contrast. -->>>

Excellent. This is the part I was unlcear on. Your response gave me a small (if silly) epiphany. Fill light! It had not occured to me before this that the purpose of fill lighting was to do anything other than lighten shadows that were too dark to show detail in the first place. The idea of adding light to already well lit areas to bring them relatively closer to the highlights then using ND or exposure adjustments is great.

The only thing that keeps me from going insane over how much I have to learn is the knowledge that I have this resource from which to learn it.

Thank you!

lyd

October 31st, 2002, 04:50 PM	#1
maddog123 Posts: n/a	zebra bars I have a GL2 that offers zebras. Can anyone tell me where I can get a detailed description or tutorial of the finer points of using this expoure guide? thanks robert

October 31st, 2002, 06:12 PM	#3
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	Nice link! Note, however, that the GL-2's zebra system offers only a low-threshold display. That is, while its display is adjustable (ex: 90IRE) it does not vanish at values above the threshold as the "70-90" setting discussed in this article does. It only vanishes when brightnesses fall below the threshold. __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

October 31st, 2002, 05:00 PM	#2
Jay Gladwell Join Date: Jul 2002 Posts: 1,244	Robert-- Check out this link, it should be of some help to you. http://www.greatdv.com/cameras/Zebra.htm

November 1st, 2002, 08:15 AM	#4
Dave Grey Regular Crew Join Date: Sep 2002 Location: Wilkes-Barre PA Posts: 34	<<<-- Originally posted by Ken Tanaka : Nice link! Note, however, that the GL-2's zebra system offers only a low-threshold display. [...] It only vanishes when brightnesses fall below the threshold. -->>> Is it a reasonable approach to use the (GL2) zebra to get correct facial highlights by setting the level to, say, 85 then adjusting exposure untill they dissappear, in a method similar to that described for the 100 IRE setting? And a related question- I keep the zebra set at 100 and generally follow the method described in the greatdv article of adjusting exposure untill they (mostly) dissapear. In order to sufficiently expose the subject in some situations, small higlights are often still zebra'ed. Is this normal/acceptable, or should I be avoiding any part of my image hitting these levels? lyd

November 1st, 2002, 08:28 AM	#5
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	<<<-- Originally posted by lydanynom : Is it a reasonable approach to use the (GL2) zebra to get correct facial highlights by setting the level to, say, 85 then adjusting exposure untill they dissappear, in a method similar to that described for the 100 IRE setting? And a related question- I keep the zebra set at 100 and generally follow the method described in the greatdv article of adjusting exposure untill they (mostly) dissapear. In order to sufficiently expose the subject in some situations, small higlights are often still zebra'ed. Is this normal/acceptable, or should I be avoiding any part of my image hitting these levels? lyd -->>> yes, and it is worthwhile to mention that any method you get familiar with...that gives you predictable results...is a method worthy of being used. I would suggest not bouncing around to a dozen different ways of finding exposure until you're well familiar with the results of one.

November 1st, 2002, 08:40 AM	#6
Jay Gladwell Join Date: Jul 2002 Posts: 1,244	I second Bill's advice. I'd would add to that: Take some time and shoot some tests. Don't forget--like it or not--you must keep notes, because you won't remember the settings for each test. Look at the footage you've shot, take note of which shot best suits YOUR taste/needs/requirements, and use that as your constant (referring to the IRE setting and use of zebra pattern). Based on the above, I have always been able to get consistant results every time I shoot.

November 1st, 2002, 08:45 AM	#7
Dave Grey Regular Crew Join Date: Sep 2002 Location: Wilkes-Barre PA Posts: 34	<<<-- Originally posted by lydanynom : [...] And a related question- I keep the zebra set at 100 [...] in some situations, small higlights are often still zebra'ed. Is this normal/acceptable, or should I be avoiding any part of my image hitting these levels?-->>> <<<-- Originally posted by Bill Ravens : yes, and it is worthwhile to mention that any method you get familiar with...that gives you predictable results...is a method worthy of being used. I would suggest not bouncing around to a dozen different ways of finding exposure until you're well familiar with the results of one. -->>> Bill, thanks for the response. I agree that sticking with one method is the way to go, for me, for now. I'm not clear on what your "yes" means relative to my second question (quoted again above). Would you mind clarifying? Thanks again. lyd

November 1st, 2002, 08:50 AM	#8
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	yes, means that setting the zebra to expose for skin tones is something done quite often by "Hollywood" videographers. I beleive the convention is to use 70IRE for the HIGHLIGHTS in caucasion skin....ie nose, forehead. A setting of 80 IRE will slightly overexpose the highlights...not really something you want to do with DV exposures. Those little areas of zebra that are "remnants" are merely indications of the contrast found in everyday scenes. The only effective way to get rid of them is to bring lighting hardware with you when you shoot and to place the lights appropriately to reduce the overall scene contrast.

November 1st, 2002, 09:04 AM	#9
Dave Grey Regular Crew Join Date: Sep 2002 Location: Wilkes-Barre PA Posts: 34	<<<-- Originally posted by Bill Ravens : [...] Those little areas of zebra that are "remnants" are merely indications of the contrast found in everyday scenes. The only effective way to get rid of them is to bring lighting hardware with you when you shoot and to place the lights appropriately to reduce the overall scene contrast. -->>> Excellent. This is the part I was unlcear on. Your response gave me a small (if silly) epiphany. Fill light! It had not occured to me before this that the purpose of fill lighting was to do anything other than lighten shadows that were too dark to show detail in the first place. The idea of adding light to already well lit areas to bring them relatively closer to the highlights then using ND or exposure adjustments is great. The only thing that keeps me from going insane over how much I have to learn is the knowledge that I have this resource from which to learn it. Thank you! lyd