zebra patterns at DVinfo.net

Bob Zimmerman · February 5th, 2002, 10:56 AM

when you are setting the aperture or shutter speed using the zebra patterns how much of the stripes do you do you try to take out? If you take them out all they way will it underexpose the other areas?

Ed Smith · February 5th, 2002, 11:15 AM

Zebra patterns I feel should only be used as a guide.
With extreme lighting conditions, there are bound to be some pattern left over, its just the way video is.
I personally don't use them much because I find them annoying when you can not see some of the picture because of the stripes.
I shoot mainly theartre where I have no say over the lighting, and so naturally some bits will be underexposed and other bits overexposed, I try and get it so that the face is never under or overexposed.

Hope this helps,

Ed Smith

Ed Smith · February 5th, 2002, 11:20 AM

Zebra patterns I feel should only be used as a guide.
With extreme lighting conditions, there are bound to be some pattern left over, its just the way video is.
I personally don't use them much because I find them annoying when you can not see some of the picture because of the stripes.
I shoot mainly theartre where I have no say over the lighting, and so naturally some bits will be underexposed and other bits overexposed, I try and get it so that the face is never under or overexposed.
So i think then that some of the pattern should remain, in the screen but not dominent.

Hope this helps,

Ed Smith

Ed Smith · February 5th, 2002, 11:27 AM

Zebra patterns I feel should only be used as a guide.
With extreme lighting conditions, there are bound to be some pattern left over, its just the way video is.
I personally don't use them much because I find them annoying when you can not see some of the picture because of the stripes.
I shoot mainly theartre where I have no say over the lighting, and so naturally some bits will be underexposed and other bits overexposed, I try and get it so that the face is never under or overexposed.
So i think then that some of the pattern should remain, in the screen but not dominent.

Hope this helps,

Ed Smith

Ed Smith · February 5th, 2002, 11:33 AM

Zebra patterns I feel should only be used as a guide.

·With extreme lighting conditions, there are bound to be some pattern left over, it’s just the way video is.

·I personally don't use them much because I find them annoying when you cannot see some of the picture because of the stripes.

·I shoot mainly theatre where I have no say over the lighting, and so naturally some bits will be underexposed and other bits overexposed, I try and get it so that the face is never under or overexposed.

·So, I think then that some of the pattern should remain, in the screen but not dominate.

Hope this helps,

Ed Smith

Bill Ravens · February 5th, 2002, 12:30 PM

it really depends where you choose to set the zebras. If you set them at 100% and you want to be compliant with NTSC broadcast standards(IRE<100), then adjust exposure so absolutely no zebra is visible. I prefer to set the zebra at 90-95 to have a little headroom below the absolute IRE100 level. In practice, if the scene is properly illuminated, there should not be any zebra. At IRE100, the whites will be washed out and all detail will be lost. The XL1s is capable of recording as high as ~IRE 110, but NTSC monitors will wash out everything over IRE100. I've seen otherwise beautiful digital video ruined with this overexposure.

John Klein · February 5th, 2002, 01:12 PM

I was wondering about that 110 IRE on the XL1S. Is that when through the s-video ports only? Is it possible to go beyond 100 via firewire?

Bill Ravens · February 5th, 2002, 02:02 PM

I've wondered about the same question you asked. I found out that most "modern" DV codecs remap the luma signal to 7.5-100 IRE anyway. If you go thru S-video and capture with MJPEG, perhaps the color mapping is kept to the full range.

Vic Owen · February 5th, 2002, 06:39 PM

From the first post, it's not obvious which camera is used -- if it's an XL-1, you can't vary the zebra setting; you're stuck at 100. For scenes over which you have no control of the lighting, go for proper exposure on the most important part, e.g. the faces mentioned above in a theater setting. I always insure that there are no zebras on the faces.

Ed Smith · February 6th, 2002, 11:27 AM

You may be wondering why there are 4 posts, which look similar?

I came across a very slow Internet connection, and because it was taking so long to load this page, and say the post was sent successfully I decided to hit the back button on the browser, which returned me to the message I was sending. Because I tried it 4 times there are now 4 replies, which look rather similar.

Sorry Guys.

Chris if you need to, please delete the first 3 replies thanks.

All the best,

Ed Smith

Vic Owen · February 6th, 2002, 05:07 PM

Ed, we just figured the needle got stuck....!

February 5th, 2002, 10:56 AM	#1
Bob Zimmerman Major Player Join Date: Nov 2001 Location: Illinois Posts: 888	zebra patterns when you are setting the aperture or shutter speed using the zebra patterns how much of the stripes do you do you try to take out? If you take them out all they way will it underexpose the other areas?

February 5th, 2002, 01:12 PM	#7
John Klein Regular Crew Join Date: Dec 2001 Location: Wisconsin, USA Posts: 182	I was wondering about that 110 IRE on the XL1S. Is that when through the s-video ports only? Is it possible to go beyond 100 via firewire? __________________ < >< . . . . . < >< . . . . . < ><

February 5th, 2002, 06:39 PM	#9
Vic Owen Major Player Join Date: Dec 2001 Location: Seattle, WA Posts: 540	From the first post, it's not obvious which camera is used -- if it's an XL-1, you can't vary the zebra setting; you're stuck at 100. For scenes over which you have no control of the lighting, go for proper exposure on the most important part, e.g. the faces mentioned above in a theater setting. I always insure that there are no zebras on the faces. __________________ -- Vic Owen --

February 6th, 2002, 11:27 AM	#10
Ed Smith Wrangler Join Date: Jan 2002 Location: Hampshire, England Posts: 1,545	4 replies You may be wondering why there are 4 posts, which look similar? I came across a very slow Internet connection, and because it was taking so long to load this page, and say the post was sent successfully I decided to hit the back button on the browser, which returned me to the message I was sending. Because I tried it 4 times there are now 4 replies, which look rather similar. Sorry Guys. Chris if you need to, please delete the first 3 replies thanks. All the best, Ed Smith

February 6th, 2002, 05:07 PM	#11
Vic Owen Major Player Join Date: Dec 2001 Location: Seattle, WA Posts: 540	Ed, we just figured the needle got stuck....! __________________ -- Vic Owen --

February 5th, 2002, 11:15 AM	#2
Ed Smith Wrangler Join Date: Jan 2002 Location: Hampshire, England Posts: 1,545	Zebra patterns I feel should only be used as a guide. With extreme lighting conditions, there are bound to be some pattern left over, its just the way video is. I personally don't use them much because I find them annoying when you can not see some of the picture because of the stripes. I shoot mainly theartre where I have no say over the lighting, and so naturally some bits will be underexposed and other bits overexposed, I try and get it so that the face is never under or overexposed. Hope this helps, Ed Smith

February 5th, 2002, 11:20 AM	#3
Ed Smith Wrangler Join Date: Jan 2002 Location: Hampshire, England Posts: 1,545	Zebra patterns I feel should only be used as a guide. With extreme lighting conditions, there are bound to be some pattern left over, its just the way video is. I personally don't use them much because I find them annoying when you can not see some of the picture because of the stripes. I shoot mainly theartre where I have no say over the lighting, and so naturally some bits will be underexposed and other bits overexposed, I try and get it so that the face is never under or overexposed. So i think then that some of the pattern should remain, in the screen but not dominent. Hope this helps, Ed Smith

February 5th, 2002, 11:27 AM	#4
Ed Smith Wrangler Join Date: Jan 2002 Location: Hampshire, England Posts: 1,545	Zebra patterns I feel should only be used as a guide. With extreme lighting conditions, there are bound to be some pattern left over, its just the way video is. I personally don't use them much because I find them annoying when you can not see some of the picture because of the stripes. I shoot mainly theartre where I have no say over the lighting, and so naturally some bits will be underexposed and other bits overexposed, I try and get it so that the face is never under or overexposed. So i think then that some of the pattern should remain, in the screen but not dominent. Hope this helps, Ed Smith

February 5th, 2002, 11:33 AM	#5
Ed Smith Wrangler Join Date: Jan 2002 Location: Hampshire, England Posts: 1,545	Zebra patterns I feel should only be used as a guide. ·With extreme lighting conditions, there are bound to be some pattern left over, it’s just the way video is. ·I personally don't use them much because I find them annoying when you cannot see some of the picture because of the stripes. ·I shoot mainly theatre where I have no say over the lighting, and so naturally some bits will be underexposed and other bits overexposed, I try and get it so that the face is never under or overexposed. ·So, I think then that some of the pattern should remain, in the screen but not dominate. Hope this helps, Ed Smith

February 5th, 2002, 12:30 PM	#6
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	it really depends where you choose to set the zebras. If you set them at 100% and you want to be compliant with NTSC broadcast standards(IRE<100), then adjust exposure so absolutely no zebra is visible. I prefer to set the zebra at 90-95 to have a little headroom below the absolute IRE100 level. In practice, if the scene is properly illuminated, there should not be any zebra. At IRE100, the whites will be washed out and all detail will be lost. The XL1s is capable of recording as high as ~IRE 110, but NTSC monitors will wash out everything over IRE100. I've seen otherwise beautiful digital video ruined with this overexposure.

February 5th, 2002, 02:02 PM	#8
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	I've wondered about the same question you asked. I found out that most "modern" DV codecs remap the luma signal to 7.5-100 IRE anyway. If you go thru S-video and capture with MJPEG, perhaps the color mapping is kept to the full range.