View Full Version : Zebra question


Vincent Oliver
June 16th, 2009, 02:01 AM
The EX3 has two zebra options, I have set Zebra 1 to 75% and then set Zebra 2 to 98%. The problem is that when I change the settings on either one then both show the last value entered. How can I set Zebra x to a set value and Zebra x to another value?

Alister Chapman
June 16th, 2009, 03:04 AM
IGNOR WHAT'S IN THIS POST... I got it wrong... see my post below.

You've found one of those mysterious EX3 menu peculiarities. If you set Zebra 0ne to say 60 and then go to Zebra 2 and set it to 90 then select BOTH you will find that both zebras will operate at the levels you set them to.

The thing is that going back to Zebra 1 (or zebra 2) and making any changes selects Zebra 1 (or 2) only, ie a single zebra and in doing so sets the level to the last level set. It's only by going to BOTH that you enable both zebras together.

It's not the most logical way to lay out the menu as it does not show you both settings together at any point, hence the understandable confusion, but you will find that both zebras will work at the independent levels you set.

Vincent Oliver
June 16th, 2009, 04:20 AM
Thank you Alister, it was confusing me. I did find out that by using the Both setting that I would display the two values as stripes, but this can leave the display looking messy. I guess I was looking for a way to switch between Zebra 1 and 2 in the same way that I can switch between the White Balance settings.

Omar Idris
June 16th, 2009, 04:31 AM
If the EX3 is anything like the EX1 then you can't actually set Zebra 2 to any value. This is a fact missed by many.
Zebra 2 only displays parts of the luminance signal that are 100% and over and can only be turned on and off. The entered values are for Zebra 1 only.

Alister Chapman
June 16th, 2009, 12:36 PM
On the EX you can set both zebras to any value between 50 and 109%

Vincent Oliver
June 16th, 2009, 12:59 PM
On the EX you can set both zebras to any value between 50 and 109%

But surely when you set one value, the other setting also takes on the same value. I have been experimenting with this today, and you are right that Zebra 2 is fixed at 100%, even though you are given the option to set it to any value.

I have now set my Zebra 1 to 80 and I am pretending that there isn't a Zebra 2. Maybe I will just dust off my old Weston V meter and use that.

Alister Chapman
June 16th, 2009, 02:36 PM
OK Folks, I've got this wrong, thanks to Omar and Jay Gladwell for pointing out to me that zebra 2 is in fact fixed at 100% (I had to go and check this as the menu gives the impression that it is adjustable). So Zebra 1 is adjustable and Zebra 2 fixed at 100. Selecting both gives you zebra 2 at 100 plus zebra 1 at whatever you set it to, changing the zebra 2 setting dosn't actually do anything.

To be honest I've never used zebra 2 and I rarely use any zebras. I have been looking very closely at how the cinegammas work, and for those I will be using zebra 1 at 60% to get skin tones in the sweet spot that should allow for optimum grading, which actually produces images that tend to look a little underexposed.

Simon Denny
July 31st, 2009, 12:02 AM
I thought I was going mad thinking that you could adjust both Zebra settings.
So just to make sure.
Zebra 2 is fixed at 100% and Zebra 1 is adjustable?
So the only way to see Zebra 1, is to turn it on in the menu, this is the sama for Zebra 2?
And just to get through my thick head, to see both Zebras, turn it on in the menu, to both.

This is very odd.
Oh well, I'll live with it.

Piotr Wozniacki
July 31st, 2009, 02:32 AM
This is not odd at all; it's all in the manual.

Zebra 1 is adjustable, and displays within the range of the level set plus/minus 10 IRE (or is it 5; don't remember).

Zebra 2 is either on or off, and displays starting at 100 and up.

Vincent Oliver
July 31st, 2009, 02:50 AM
The odd bit is that you think you are adjusting the level with zebra two, whereas you are actually readjusting the level of zebra one. To make things easier, Sony could have disabled the level adjustment when the Zebra two is highlighted.

Just a simple confusion

Piotr Wozniacki
July 31st, 2009, 03:04 AM
The odd bit is that you think you are adjusting the level with zebra two, whereas you are actually readjusting the level of zebra one. To make things easier, Sony could have disabled the level adjustment when the Zebra two is highlighted.

Just a simple confusion

Agreed, Vincent - the menu setting procedure can be confusing. But not if you've RTFM :)

Vincent Oliver
July 31st, 2009, 03:06 AM
Agreed, Vincent - the menu setting procedure can be confusing. But not if you've RTFM :)

Read The Full Manual, you must be joking - too busy making mistakes. :-)

Piotr Wozniacki
July 31st, 2009, 03:08 AM
This is a good one, ha ha :)

Simon Denny
July 31st, 2009, 10:44 AM
Oh, the manual. Well I guess I should read the thing one day.
Why then do they have a setting for the second zebra if you can't change the thing.
I was thinking that this was going to be an upgrade at some point and Sony have forgot to do it.

Leonard Levy
July 31st, 2009, 11:00 AM
Vincent, why have you set you zebra 1 to 80%. Most people set it for caucasian flesh tone at 70% or 60% which i prefer for HD.
Nice thing about the Zebra 1 is that it is so light , that it is not annoying to shoot with it on.

Vincent Oliver
July 31st, 2009, 11:29 AM
Vincent, why have you set you zebra 1 to 80%. Most people set it for caucasian flesh tone at 70% or 60% which i prefer for HD.
Nice thing about the Zebra 1 is that it is so light , that it is not annoying to shoot with it on.

Typo, it should read 70%

Dave Morrison
July 31st, 2009, 07:00 PM
I'm a little curious about using 70% (or whatever setting you prefer) for gauging the correct exposure for skintones. Given the plethora of complexions, how can you settle on anything?

Doug Jensen
July 31st, 2009, 10:11 PM
I'm a little curious about using 70% (or whatever setting you prefer) for gauging the correct exposure for skintones. Given the plethora of complexions, how can you settle on anything?

It can't!!!!
I've been trying to tell people this for years. Pick any three people at random on a New York street and I'll show you how 70% can't be right for all (or maybe any) of them.

A calibrated gray card of known reflectance value or something bright white are the only two reliable targets for zebra.

Dave Morrison
July 31st, 2009, 10:15 PM
Thanks. I thought I was the only one who thought that this was a little nutty. The palm of the hand is about the only part that seems to have any uniformity. But grey card.....yes.

Vincent Oliver
August 1st, 2009, 01:42 AM
OK, I will come clean on this. Generally I have my Zebra 1 set to 70+, depending on subject matter I may vary this up or down by 10%, as Doug says no two skin tones are alike. I also use the LCD viewfinder to judge the overall exposure, but this does require you to set up the screen accurately. I use the Colour (Color) bars for setting up the display, and may check this a couple or more times during a shoot – the contrast and brightness buttons may get moved especially if you fumble to turn up peaking etc. Shame Sony couldn’t have incorporated a lock on these. I also occasionally use the Histogram, just to check that shadows or highlights have not been totally lost.

My background is as a stills photographer and I spent many years studying and using the Ansel Adams Zone system of exposure. This has helped me to understand which areas to take a reading from and how to interpret that reading. It’s surprising how many photographers will shoot a snow scene and wonder why the snow looks grey. Of course the Zone system also relies on developing the film to compensate for high or low contrast scenes etc. This is something that can’t be easily translated to digital capture, although I am working on it.

In short I use a combination of Zebra, Histogram, eye balls and experience to judge exposure, and generally I get it right to within ½ stop most of the time, any small variation can be corrected it in my NLE.

If you want a good fail safe method, then set your Zebra to 98% and then set the aperture so the lines on highlight areas just vanish, this should produce the correct exposure but keep an eye on the dark areas making sure they don’t block up. Or as suggested use a Kodak 18% grey card (available from most good pro dealers)

Steve Phillipps
August 1st, 2009, 02:05 AM
If you want a good fail safe method, then set your Zebra to 98% and then set the aperture so the lines on highlight areas just vanish, this should produce the correct exposure but keep an eye on the dark areas making sure they don’t block up. Or as suggested use a Kodak 18% grey card (available from most good pro dealers)

Agreed, this has to be the best method these days as NLEs have such good grading controls that as long as you preserve your highlights and ideally use gamma and knee settings to maximise dynamic range you'll have the most information in the picture to work with. The only exception is quick turnaround news-type stuff where they will be no time for grading, in this case you want to get a pretty picture straight out of the camera.

Steve

Anthony McErlean
August 1st, 2009, 06:31 AM
If you want a good fail safe method, then set your Zebra to 98% and then set the aperture so the lines on highlight areas just vanish, this should produce the correct exposure but keep an eye on the dark areas making sure they don’t block up. Or as suggested use a Kodak 18% grey card (available from most good pro dealers)

Thanks Vincent for the tip, I find it very difficult getting used to the EX3 viewfinder and also in getting it set with the brightness/contrast controls.

I've recorded with clips under exposed and some slightly over exposed. I'm going to try that and see how that goes.

Thanks again.

Sverker Hahn
August 3rd, 2009, 05:47 AM
Strange behaviour of zebra1: sometimes I get zebra1 stripes not all the way to zebra2, therefore leaving an area between the two with no stripes at all. I thought it should cover everything from e.g. 70% to 100%, where zebra2 takes over.

Piotr Wozniacki
August 3rd, 2009, 05:58 AM
Strange behaviour of zebra1: sometimes I get zebra1 stripes not all the way to zebra2, therefore leaving an area between the two with no stripes at all. I thought it should cover everything from e.g. 70% to 100%, where zebra2 takes over.

It's a normal behaviour - see http://www.dvinfo.net/conf/1179015-post9.html

Leonard Levy
August 3rd, 2009, 02:09 PM
When you use the zebra for exposure you are usually running and gunning - shooting very fast with no monitor. As a rough guide so my exposures are safe I put my zebra @ 60%, and look to see it on caucasian faces. If I'm shooting darker people I may lower it.

Its not science nor is it exact, its just a way to save your ass in a rough and tumble situation. It works and has been used by video shooters for many many years.
In SD we usually set it at 70. Many find 60 better for HD.

Sverker Hahn
August 3rd, 2009, 05:17 PM
It's a normal behaviour - see http://www.dvinfo.net/conf/1179015-post9.html

OK, thanks, Piotr.

Simon Denny
August 3rd, 2009, 05:51 PM
Leonard,
With 60% zebras are you looking for highlights on the face or all over the face?

Leonard Levy
August 3rd, 2009, 07:41 PM
Wherever I would expect to see a solid flesh tone, depending on the lighting and the situation. Certainly not all over the face.

Like I said before its not a science. People on this forum really overthink a lot of exposure and color balance issues IMHO. If I have time I always have a monitor I know with a waveform and I trust that to get me very close. I do care a great deal about accurate color and exposure.

However, If I'm in run and gun territory then I just want to make sure I have an exposure and color balance that's close enough. Running 2 zebras at 100 and at 60 or so is a big help. So is balancing off any piece of white paper or napkin or cloth you can find. Personally I favor computer printer paper- don't ask me why as its not all the same. I also carry a little swatch book of gels to cheat if I have mixed light or something looks green on my viewfinder. Its never failed me and I think what I'm describing is typical of professional shooters.