zebra stripes at DVinfo.net

Steve Witt · November 29th, 2005, 11:51 AM

Hi folks. Shooting digital video in my house during certain hours of the day, it is almost impossible to get rid of all the zebra strips showing on my LCD. I want the most professional looking footage I can shoot. (I don't have a project going on right now I'm just trying to learn how to get the shots when I want them) My question is: Is it acceptable to have a few items in the frame overexposed (zebra stripes) or is the goal always to rid of "ALL" stripes. I'm just having a tough time getting rid of all of them and then still getting good exposure on the rest of the shot. I've tried stopping down and/or increasing shutter speed until stripes are gone but then the rest of the frame is too dark. Should I buy ND filters or will this give the same results as stopping down too much. I don't have any shades to reduce light in the family room where we shoot....and I just want to work with what light comes in and deal with it somehow with the camera "to learn camera techniques". Sometimes, the overexposed area is an object that can be removed, like a magazine or picture frame but I just want to see what a professional would do in these cases. Thanks.

Joshua Provost · November 29th, 2005, 01:50 PM

Steve,

What camera do you have?

What would a professional do? Cover the window... not shoot in front of the window... shoot with the window at the shooters back... add more light to the interior... use a on-camera light... many things.

You camera probably has a backlight mode, so it will expose for the foreground, but as you mention, this will blow out the window. Is that acceptable to you? It probably isn't if you are making a professional video production, but it's OK for home videos of the family.

Do you have to eliminate all of the zebras? That depends on where the zebras show up? 80% 90% 100% If they come in at less than 100%, you can have a few and not overexpose.

If your camera has a CineGamma function or manual control of contrast, you can work with those settings to get more latitude out of the camera.

ND filters won't do any good. They will cut the light, allowing you to work with the iris open wider, but the overall contrast of the scene will be the same. A low contrast filter might do some good, but the results I have seen have not been that pleasing.

You could expose for the highlights and adjust the gamma in your NLE afterwards, bringing up the midtones and shadows, but if there is too much contrast, it won't look that good.

Josh

Adam Keen · November 29th, 2005, 04:32 PM

You should have parts that will be bright and get the zebra. Watch the footage and see if there is detail in highlights. Magazines and frames are glossy, so you're probably getting specular highlights. Pros would use dulling spray or adjust its angle in relation to lights and the camera. Light from outside could be reduced with large ND sheets. A cheaper route would be to use black fiberglass screen material or glare reducing vinyl window cling. A bedsheet hung on the window properly can look just like curtains.

Anyone know why there isn't zebra stripes for black?

Josef Heks · November 29th, 2005, 07:17 PM

hi steve,

Like u, I have found that with digital video (i have a gs400), it can often be pretty hard to find a nice balance between dark and light areas.

Basically, the reason is that DV has limited "latitude" compared to film - i.e. it cant handle bright and dark areas simultaneously. That said, remeber to follow all the tips Josh gave above. If you have to shoot into light, use extra lights to lighten up the darker areas, then reduce the apature to find a better balance.

There are no filters which i know of which would really help. If you have the gs400, a tip i learned of Josh was to use "picture adjustment" to turn down the contrast, this is quite effective, though watch it doesnt flatten your images too much.

Josef
___________________________
Moderator Note: This post was edited since it contained a link to an active discussion on another site. We're happy for you to share your impressions here at DVinfo, but can't allow links like this since it isn't possible for our members to participate in discussions at other sites. Thanks for your understanding

Adam Keen · November 29th, 2005, 08:42 PM

Tiffen makes contrast filters. http://www.tiffen.com/contrast_filters.htm

John Hartney · November 29th, 2005, 08:54 PM

While there is less latitude with video than film, stripes work to show proper exposure when set to 70 or 80% depending on your camera... if your picture is dark when exposing below the zebra, it may be that it is set at 70% and that's what you should look for on flesh, stripes mean proper exposure. I keep my cameras at 70% and use it as a light meter.

Sean McHenry · November 29th, 2005, 11:40 PM

Most zebras are selectable these days in the higher end cameras. Some, like mine even have 2 zebras. I set one to 70% and the other to 100%.

You can use things like ND (Neutral Density) filters over the windows, but that's messy as the size of material you might need is rather large. I go the other route and throw on more light inside. You are bringing up the overall level of light but you have control now.

Try setting your camera so the zebra is just visible for the brightest areas of sunlit clouds outside your window. Using a light source, hardware store lamps, specialized TV lighting kits, etc, add light to your subjects until they too look good. I suggest a larger monitor for this function.

You will probably seldom have the ability to keep the zebra completly in check. The dynamic range or latitude is vast and you can only record a slice of it. There will be give and take.

One last note. It is often easier to pull detail out of dark areas using your NLE editing software than it is to get detail from the cut off highlights. If the top end, the highlites, are "clipped" there is no way to get that detail back.

Lots of good books and even DVDs on the subject. Try the DV Enlightenment DVD or browse the selection frm places like American Cinematographer or Millimeter Magazine, our sponsosrs or Film Tools, Videoguys, etc.

Sean McHenry

Mike Cavanaugh · November 30th, 2005, 08:19 AM

Quote:

Originally Posted by Adam Keen

Anyone know why there isn't zebra stripes for black?

Adam, I've just started using Serious Magic's DV Rack software on a laptop to use as a video monitor during shoots. It has variable dual zebra bars that can be set for white or black as well as a vector scope and wave form monitor. So far it seems like a pretty neat tool for checking video quality during a shoot. It has audio monitors as well.

I'm not associated with the company and have not gotten too deep into the software - but so far I like what I see.

John Rofrano · December 2nd, 2005, 08:51 AM

Quote:

Originally Posted by Mike Cavanaugh

Adam, I've just started using Serious Magic's DV Rack software on a laptop to use as a video monitor during shoots.

I do all of my studio shooting with DV Rack. I can’t say enough good things about it. It will really help you set up the perfect shot and let you know exactly what you are getting on tape. DV rack uses a step-by-step process that you follow to get perfect focus, white balance, and exposure. Obviously you will still have to balance your exposure with lighting but it’s a big help in that area. There is a trial you can download to see if you think it’s worth getting. I love it.

If you’ve got a lot of natural light coming in that is blowing the exposure, get yourself some reflectors and use that light to your advantage to light up the dark areas and then stop down the camera. Otherwise, shoot at night and provide all your own light (that’s what I do)

~jr

Steve Witt · December 4th, 2005, 12:18 AM

Thanks to all. I have a GS400 camcorder and so far I love it. Of all the stuff I've tried to learn about digital video/making movies so far, this lighting/exposure thing has been the toughest to figure out. I am currently reading Ross Lowell's "Matters of Light and Depth" to help out. Does anyone know what Ross is talking about when he talks about "lighting in planes"? I asked this question on another site too. Anyhow, when mentioning "planes" does he mean the different surfaces and angles of the subject.....or is he talking about the layers of a scene like the forground, the subject, and the background?
John Rofrano, I like the idea about shooting at night. I guess a blank canvas to a lighting pro would be darkness. I will try this too.

Graham Bernard · December 4th, 2005, 02:32 AM

I like and do use JR's suggestion of reflectors. One draw back to take on board here is that the Sun's light not only comes and goes with the passage of clouds, the atmosphere is also variable, but the Earth is slowly rotating around this "free" light source. Meaning the angles of illumination do change.

Having just begun my journey on this "illuminating" rite of passage, I'm using a combination of reflectors bouncing off light from my lights and any existing lights I can utilise.

. . another thing - take as many takes as you can!

Grazie

November 29th, 2005, 11:51 AM	#1
Steve Witt Major Player Join Date: Feb 2005 Location: kentucky, USA Posts: 429	zebra stripes Hi folks. Shooting digital video in my house during certain hours of the day, it is almost impossible to get rid of all the zebra strips showing on my LCD. I want the most professional looking footage I can shoot. (I don't have a project going on right now I'm just trying to learn how to get the shots when I want them) My question is: Is it acceptable to have a few items in the frame overexposed (zebra stripes) or is the goal always to rid of "ALL" stripes. I'm just having a tough time getting rid of all of them and then still getting good exposure on the rest of the shot. I've tried stopping down and/or increasing shutter speed until stripes are gone but then the rest of the frame is too dark. Should I buy ND filters or will this give the same results as stopping down too much. I don't have any shades to reduce light in the family room where we shoot....and I just want to work with what light comes in and deal with it somehow with the camera "to learn camera techniques". Sometimes, the overexposed area is an object that can be removed, like a magazine or picture frame but I just want to see what a professional would do in these cases. Thanks.

November 29th, 2005, 01:50 PM	#2
Joshua Provost Major Player Join Date: Sep 2004 Location: Phoenix, AZ Posts: 493	Steve, What camera do you have? What would a professional do? Cover the window... not shoot in front of the window... shoot with the window at the shooters back... add more light to the interior... use a on-camera light... many things. You camera probably has a backlight mode, so it will expose for the foreground, but as you mention, this will blow out the window. Is that acceptable to you? It probably isn't if you are making a professional video production, but it's OK for home videos of the family. Do you have to eliminate all of the zebras? That depends on where the zebras show up? 80% 90% 100% If they come in at less than 100%, you can have a few and not overexpose. If your camera has a CineGamma function or manual control of contrast, you can work with those settings to get more latitude out of the camera. ND filters won't do any good. They will cut the light, allowing you to work with the iris open wider, but the overall contrast of the scene will be the same. A low contrast filter might do some good, but the results I have seen have not been that pleasing. You could expose for the highlights and adjust the gamma in your NLE afterwards, bringing up the midtones and shadows, but if there is too much contrast, it won't look that good. Josh __________________ Owner/Operator, 727 Records Co-Founder, Matter of Chance Productions Blogger, Try Avoidance

November 29th, 2005, 08:54 PM	#6
John Hartney Major Player Join Date: Jun 2003 Location: Elgin, Illinois Posts: 206	While there is less latitude with video than film, stripes work to show proper exposure when set to 70 or 80% depending on your camera... if your picture is dark when exposing below the zebra, it may be that it is set at 70% and that's what you should look for on flesh, stripes mean proper exposure. I keep my cameras at 70% and use it as a light meter. __________________ John Hartney Elgin, Illinois USA 847.742.9321

November 29th, 2005, 11:40 PM	#7
Sean McHenry Trustee Join Date: Mar 2004 Location: Hilliard, Ohio Posts: 1,193	Most zebras are selectable these days in the higher end cameras. Some, like mine even have 2 zebras. I set one to 70% and the other to 100%. You can use things like ND (Neutral Density) filters over the windows, but that's messy as the size of material you might need is rather large. I go the other route and throw on more light inside. You are bringing up the overall level of light but you have control now. Try setting your camera so the zebra is just visible for the brightest areas of sunlit clouds outside your window. Using a light source, hardware store lamps, specialized TV lighting kits, etc, add light to your subjects until they too look good. I suggest a larger monitor for this function. You will probably seldom have the ability to keep the zebra completly in check. The dynamic range or latitude is vast and you can only record a slice of it. There will be give and take. One last note. It is often easier to pull detail out of dark areas using your NLE editing software than it is to get detail from the cut off highlights. If the top end, the highlites, are "clipped" there is no way to get that detail back. Lots of good books and even DVDs on the subject. Try the DV Enlightenment DVD or browse the selection frm places like American Cinematographer or Millimeter Magazine, our sponsosrs or Film Tools, Videoguys, etc. Sean McHenry __________________ ‘I don’t know what I’m doing, and I’m shooting on D.V.’ - my hero - David Lynch http://www.DeepBlueEdit.com

November 29th, 2005, 04:32 PM	#3
Adam Keen Regular Crew Join Date: Nov 2005 Posts: 49	You should have parts that will be bright and get the zebra. Watch the footage and see if there is detail in highlights. Magazines and frames are glossy, so you're probably getting specular highlights. Pros would use dulling spray or adjust its angle in relation to lights and the camera. Light from outside could be reduced with large ND sheets. A cheaper route would be to use black fiberglass screen material or glare reducing vinyl window cling. A bedsheet hung on the window properly can look just like curtains. Anyone know why there isn't zebra stripes for black?

November 29th, 2005, 07:17 PM	#4
Josef Heks Regular Crew Join Date: Nov 2005 Posts: 74	hi steve, Like u, I have found that with digital video (i have a gs400), it can often be pretty hard to find a nice balance between dark and light areas. Basically, the reason is that DV has limited "latitude" compared to film - i.e. it cant handle bright and dark areas simultaneously. That said, remeber to follow all the tips Josh gave above. If you have to shoot into light, use extra lights to lighten up the darker areas, then reduce the apature to find a better balance. There are no filters which i know of which would really help. If you have the gs400, a tip i learned of Josh was to use "picture adjustment" to turn down the contrast, this is quite effective, though watch it doesnt flatten your images too much. Josef ___________________________ Moderator Note: This post was edited since it contained a link to an active discussion on another site. We're happy for you to share your impressions here at DVinfo, but can't allow links like this since it isn't possible for our members to participate in discussions at other sites. Thanks for your understanding

November 29th, 2005, 08:42 PM	#5
Adam Keen Regular Crew Join Date: Nov 2005 Posts: 49	Tiffen makes contrast filters. http://www.tiffen.com/contrast_filters.htm

December 4th, 2005, 12:18 AM	#10
Steve Witt Major Player Join Date: Feb 2005 Location: kentucky, USA Posts: 429	Thanks to all. I have a GS400 camcorder and so far I love it. Of all the stuff I've tried to learn about digital video/making movies so far, this lighting/exposure thing has been the toughest to figure out. I am currently reading Ross Lowell's "Matters of Light and Depth" to help out. Does anyone know what Ross is talking about when he talks about "lighting in planes"? I asked this question on another site too. Anyhow, when mentioning "planes" does he mean the different surfaces and angles of the subject.....or is he talking about the layers of a scene like the forground, the subject, and the background? John Rofrano, I like the idea about shooting at night. I guess a blank canvas to a lighting pro would be darkness. I will try this too.

December 4th, 2005, 02:32 AM	#11
Graham Bernard Old Boot Join Date: Aug 2002 Location: London UK Posts: 3,633	I like and do use JR's suggestion of reflectors. One draw back to take on board here is that the Sun's light not only comes and goes with the passage of clouds, the atmosphere is also variable, but the Earth is slowly rotating around this "free" light source. Meaning the angles of illumination do change. Having just begun my journey on this "illuminating" rite of passage, I'm using a combination of reflectors bouncing off light from my lights and any existing lights I can utilise. . . another thing - take as many takes as you can! Grazie