Zebras at DVinfo.net

Pete Cofrancesco · September 22nd, 2009, 09:33 PM

Help me with my understanding of Zebras. In the past I have set my camera to 90 or 100, increasing my exposure until I see the start of zebras on highlights of white objects like a person's shirt. The fellow who I'm working for doing depositions told me to set my zebras to 80 which he explained is the "industry standard" and to leave some zebras on the whites. Is this the best approach?

I always thought that the zebra numbers indicated the areas of pure white. So when set to 100 zebras would indicate areas of 100% white with the details being lost, and 80 would give you a safety margarine of 20%. But I read some where that number indicates the areas of your image that are that value. So if it's set to 50 all areas that are 50% gray would have zebras, values higher and lower would not.

Josh Bass · September 23rd, 2009, 12:37 AM

I had a similar thread, if you want to search for it. Personally, I leave mine at 100 as a rough guide, and eyeball exposure from there.

I've heard it said skin tones expose "correctly" at 70 or 75%, so that maybe where your 80% got his numbers from.

Yes, the idea is that zebras turn on when part of your frame is at or above the selected value. So if they're set for 70, then anything in your frame 70 or above will show zebras. (I might be off here, some cams might have zeebs that, perhaps turn on at, for example 70, if you're set for 70, but then turn off at a certain higher value, like 80)

Some cams have two different zebra patterns, to which you can set two different values. . .say 70 and 100. So you would have a good skin reference and also know when you've hit pure white anywhere in frame.

Geoffrey Cox · September 23rd, 2009, 12:15 PM

I use an XH-A1 and shot a lot of footage in very bright conditions recently with zebras at 80% but found overall things were often underexposed. Better than overexposed though as I could brighten things easily in post and it did give lovely contrast. I think about 90% would be best,

Geoff

Dean Sensui · September 23rd, 2009, 12:50 PM

My EX1 has two zebras. One is always set at 100% (the camera was designed that way) and the other is at 80%.

80% is to ensure detail is retained in white objects. Everything else falls below that. 100% is reserved for the brightest speculars and light sources.

Sometimes a situation arises where a bright spot in the background is unavoidable, and I have to open up more than I'd like in order to get detail in a darker foreground. And for what I shoot, sometimes I can't choose a different camera position and there's no option of adding light into the darker area.

In post, I set whites at about 90% and do other tweaks to get everything to look right.

Jim Snow · September 23rd, 2009, 03:39 PM

You should be careful, whichever type of zebra pattern that you chose to use, to make sure that you set exposure based on the subject of the shot. There may well be parts of a frame that you allow to be too light or dark because they aren't relevant to the shot.

Grinner Hester · October 1st, 2009, 12:47 PM

You'll find if you set em to 100, you can adjust just so whites are in zebra. If no white is in the scene you should see no zebras. It helps alot until ya get an eye for it. In the end, you'll always go by your scopes in post.

Adam Grunseth · October 3rd, 2009, 06:21 PM

I set my zebras to show between 75% and 95% in order to get consistent exposure of my subject's skin. When I am shooting, I expose so that the zebra stripes start to appear on the highlights of a white person's skin (75%). Then at 95% when the zebras vanish, I know I am approaching that 100% level where I will be loosing detain.

However, that is just what works for me. I work with shooters who have been doing this since before I was born, and they all have their own ways of using zebra stripes. I don't think there is one standard way to use them, it is up to the individual shooter. Figure out what works for you, then do it :-)

September 22nd, 2009, 09:33 PM	#1
Pete Cofrancesco Inner Circle Join Date: May 2004 Location: USA Posts: 3,005	Zebras Help me with my understanding of Zebras. In the past I have set my camera to 90 or 100, increasing my exposure until I see the start of zebras on highlights of white objects like a person's shirt. The fellow who I'm working for doing depositions told me to set my zebras to 80 which he explained is the "industry standard" and to leave some zebras on the whites. Is this the best approach? I always thought that the zebra numbers indicated the areas of pure white. So when set to 100 zebras would indicate areas of 100% white with the details being lost, and 80 would give you a safety margarine of 20%. But I read some where that number indicates the areas of your image that are that value. So if it's set to 50 all areas that are 50% gray would have zebras, values higher and lower would not.

September 23rd, 2009, 12:37 AM	#2
Josh Bass Slash Rules! Join Date: Apr 2002 Location: Houston, Texas Posts: 5,472	I had a similar thread, if you want to search for it. Personally, I leave mine at 100 as a rough guide, and eyeball exposure from there. I've heard it said skin tones expose "correctly" at 70 or 75%, so that maybe where your 80% got his numbers from. Yes, the idea is that zebras turn on when part of your frame is at or above the selected value. So if they're set for 70, then anything in your frame 70 or above will show zebras. (I might be off here, some cams might have zeebs that, perhaps turn on at, for example 70, if you're set for 70, but then turn off at a certain higher value, like 80) Some cams have two different zebra patterns, to which you can set two different values. . .say 70 and 100. So you would have a good skin reference and also know when you've hit pure white anywhere in frame. __________________ The Bass' camerawork The Bass on IMDB

September 23rd, 2009, 12:50 PM	#4
Dean Sensui Inner Circle Join Date: Oct 2001 Location: Honolulu, HI Posts: 2,054	My EX1 has two zebras. One is always set at 100% (the camera was designed that way) and the other is at 80%. 80% is to ensure detail is retained in white objects. Everything else falls below that. 100% is reserved for the brightest speculars and light sources. Sometimes a situation arises where a bright spot in the background is unavoidable, and I have to open up more than I'd like in order to get detail in a darker foreground. And for what I shoot, sometimes I can't choose a different camera position and there's no option of adding light into the darker area. In post, I set whites at about 90% and do other tweaks to get everything to look right. __________________ Dean Sensui Exec Producer, Hawaii Goes Fishing

September 23rd, 2009, 12:15 PM	#3
Geoffrey Cox Major Player Join Date: Aug 2008 Location: Huddersfield, UK Posts: 469	I use an XH-A1 and shot a lot of footage in very bright conditions recently with zebras at 80% but found overall things were often underexposed. Better than overexposed though as I could brighten things easily in post and it did give lovely contrast. I think about 90% would be best, Geoff

September 23rd, 2009, 03:39 PM	#5
Jim Snow Trustee Join Date: Mar 2009 Location: Santa Clara, CA Posts: 1,104	You should be careful, whichever type of zebra pattern that you chose to use, to make sure that you set exposure based on the subject of the shot. There may well be parts of a frame that you allow to be too light or dark because they aren't relevant to the shot.

October 1st, 2009, 12:47 PM	#6
Grinner Hester Regular Crew Join Date: Nov 2004 Location: services world-wide Posts: 118	You'll find if you set em to 100, you can adjust just so whites are in zebra. If no white is in the scene you should see no zebras. It helps alot until ya get an eye for it. In the end, you'll always go by your scopes in post.

October 3rd, 2009, 06:21 PM	#7
Adam Grunseth Major Player Join Date: May 2005 Location: Eugene Oregon Posts: 393	I set my zebras to show between 75% and 95% in order to get consistent exposure of my subject's skin. When I am shooting, I expose so that the zebra stripes start to appear on the highlights of a white person's skin (75%). Then at 95% when the zebras vanish, I know I am approaching that 100% level where I will be loosing detain. However, that is just what works for me. I work with shooters who have been doing this since before I was born, and they all have their own ways of using zebra stripes. I don't think there is one standard way to use them, it is up to the individual shooter. Figure out what works for you, then do it :-)