Zebra setting for broadcast

[Brendan Sundry]

Hello all,

I have set my Zebra at 75% for PAL broadcast, just want to know anyone else uses this setting. I dont want to get to hot obviously.

B.Sundry

[Robin Davies-Rollinson]

It all depends on your own preferences and interpretation of your zebra display - there is no right or wrong!
My preference is to use 90% zebra, but that's just me...

Robin

[Leo Pepingco]

Mine is 100+ setting...... I use a lot of outdoor stuff and if I can get no zebera pattern, I usually think I have good exposure.... but 80-90 percent is also sufficient in daylight and indoors IMHO

[Michael Hendrix]

Many people set zebras at 80%, especially when doing interviews as that is the proper exposure for skin tones. My preference is to set them at 100% as I just want to know when I am over exposed.

[Robin Davies-Rollinson]

The trouble with lower percentage settings ( I know some cameramen who use 70%) is that the viewfinder gets cluttered with the zebras and can be very distracting - but to each his own...
Like I said, it still comes back to your own interpretation in the end.


Robin

[Leo Pepingco]

To me, 70% is a bit much.... I live by the rule of "If its 80% and higher, then having no lines means its good exposure"

70% gets cluttered IMO, and often can get in the way... but yes, his to his own.

[Mark Utley]

I usually don't even use zebra. I just look at people's faces through the LCD and if there are any points of solid colour (no detail), I iris down a bit. It's worked for me.

[Brendan Sundry]

We'll im shooting outside, and im worried about overexposing, but i havnt shot dv for a while and understand it hs more leeway than say sony's XDCAM

I guess im wondering do i rely on the zebra or just go stuff it and use my own discretion as im not very comfortable with it. I just shot some greenscreen stuff with 80% letting the zebras just come thru on the skin highlights. DOes this sound like its a correct exposure?

B.Sundry

[Leo Pepingco]

IMHO Brendan, I think only having the lines show on facial highlights is a good guidline.

Remember, always know the tone of the shot. Having a romance film requires a lot of warm lighting and often NO overexposure... so no lines at all...

Faster films can get away with some really cool highlight flashese etc...

Films that show heat, or temperature (ie Summer) would also be known to have the occasional sun flare and blightness etc...

[Greg Boston]

Originally Posted by Brendan Sundry

We'll im shooting outside, and im worried about overexposing, but i havnt shot dv for a while and understand it hs more leeway than say sony's XDCAM

Depends on what flavor you are recording to XDCAM. XDCAM refers to the recording media and has nothing to do with image lattitude. If you are concerned about highlight blowouts, just know that XDCAM cameras will give you more image lattitude due to larger sensors. IOW you can expose for the highlights and not completely lose the faces in the dark in the process.

gb

[Brendan Sundry]

Thanks Greg the cam was a 530p (50mbit).

As far as the shoot went, It was a cloudy day, and at 80 the footage seemed a bit under. But looked correct in the LCD. I am kind of annoyed i didnt trust my instinct and just go with a my gut rather than the zebra. I think what i really need to do are some tests before next time.

Its hard going from a big form factor to a small form factor. Well, its hard going from any one camera your used to to another your not.

Loved the focus assist feature!

B.Sundry

[Michael Hendrix]

Be careful about judging by the viewfinder is that is what you refer to by the LCD. I have used cameras before that the photographer before me adjusted the brightness of the viewfinder and it took a few shots too realize as I wasnt using a monitor.

[Tom Tanquary]

Hi All, I'm new to this forum - having just bought a Z1 - and this thread caught my interest right off.

I've been shooting video since 1977 and the introduction of the zebra pattern for exposure has been a total blessing. But, from the discussion above it seems not many people know how to use them. Zebras indicate a specific exposure level for a reflective surface at that iris opening. Overall exposure of any scene is determined by many other factors. Like a spot meter to a still photographer, the zebras can be very helpful if you use them on a known reference surface to determin proper exposure. And proper exposure simply means the "look" you want to get.

Virtually all professional video cameras come with the zebras set at 70 which means 70% of a full signal. Even the pre-set on my PD-150 has only 100 and 70 as its zebra choices. There's a reason for that. While each camera system will have a different dynamic range between 7.5 (black) and 100 (pure white), certain constants will always be true. The number 70 was picked for 2 basic reasons: it's the proper exposure for a white sheet of paper while still seeing detail on it (such as writing, or it's texture) and it's the level of typical skin exposure where detail begins to be lost.

Skin tones usually fall between 55 and 65% for a very natural, well detailed, chroma-rich look. At 70% skin will start to "shine." At 75% you are loosing detail, and at 80% most all the detail is gone. That maybe fine if you're trying to make an old actress look 20 years younger, but in general it means that the person's face is bland, pale and washed out. If the 70% zebras just barely appear on the most reflective portions of a face, like a cheek or upper forehead, then the rest of face falls into that 55 to 65 range. It's a very simple way to maintain a consistant good look.

But many times the scene is wider than a single face and other exposure factors may take over. Wide shots of people directly lit by the sun may have their faces at more than 70% to acchieve an overall good exposure. A washed out face in this case is hardly noticeable and that screen area is too small for much detail anyway. It's at this point that the dynamic range of the camera comes into play. Which is more important: the shadows or the highlights?

Setting zebras at 100 has never made sense to me. 100 is pure white, no detail. So what? There are so many things in a scene that will be over-exposed long before you get to 100. The white paper is a good example. At 90% that paper is blooming big time, at 100 it's gone. Most all of your exposure decisions are made well under the 100% video level. Which is why professional videographers have always used 70 as a benchmark. Most all surfaces in the upper third of reflective quality (reflect the most light) will start to loose detail above 70%. Whether it's human skin, a white piece of paper, or a sun lit concrete wall, those zebras let you know how much detail you'll get at that iris.

Trusting a tiny viewfinder, that may be out of adjustment, who's picture quality is determined by the angle of your eye to it, under less than ideal viewing conditions is a dangerous way to make decisions on exposure.

And there's this little switch on the back of the camera that can easily turn off the zebras once your exposure is set.

Sorry. This is just one of my pet-peeves.

[Wayne Orr]

Excellent post, Tom. I hope everyone reads it and takes it to heart. I agree, there seems to be a lot of confusion in this thread about what to look for in relation to the zebras and the actual picture.

For instance, Brendan says that it was a "cloudy day, and at 80 the footage seemed a bit under." Huh? What was "at 80" Brendan? The sky? Trees? Buildings? Grass? Faces? Certainly not all areas of your picture. The zebras work best on faces, or as they like to say, "a normal caucasion skin tone." If you are getting 80% highlights on caucasion skin tones, you are almost certainly getting washed out faces, similar to a lot of news footage.

OTOH, if you are getting 80% zebras in an overcast sky, I could see where your footage would be generally underexposed. BTW, when you expose properly, overcast days are a delight. 360 degree shooting and no racoon eyes. That is, if you are shooting with 70% zebras, and seeing just a hint of zebras in cheek bones, bridge of the nose, etc, like Tom mentioned.

BTW, normally, if you underexpose video a bit, it looks pretty good. Not so if you overexpose it. And of course, there is room to improve the look in post if you haven't blown out the highlights, or crushed the blacks.

You might try this if you have access to a good monitor and maybe a waveform. Lock you camera down on a nice portrait shot from a magazine that has a bit of highlight area in it. Try the 70% zebras, and set them in the highlight areas of the face. Then check your monitor and see how the picture looks. Check your waveform and see where the overall flesh tones fall. As Tom said, are they in the 55-65 range? If everything checks out OK, you are good to go. You might also see what setting the camera arrives at using your auto iris. Auto iris can definitely be your friend.

No face in your outside shot? Understand that the auto iris can be fooled by a hot sky into giving you a lower exposure than you should use, so tilt down and get the sky out of the picture (completely or partially), use auto to set the iris, lock in the setting and reframe to include part of the sky. The sky may be burned out, but you have determined that it is not the important part of your scene. Experiment.

Wayne Orr, SOC

[Brendan Sundry]

Wayne and Tom great points, a month later and im still trying to figure this thing out, but im a lot closer.

I did another shoot, indoors soon after i used a trial version of DV RACK (thanks guys) and got good exposure, using the waveform in this program. I had the zebra set at 90 this time, (looking at skin tones) and backed it off a bit and then used dv rack to see how close i was.

Now i know 90 is crazy (in hindsight) for the skin tones, (even backed off a bit) but it seems that the fx1 has such little dynamic range that if your way over and you stop down the tinniest bit, then your on the money.

So whatever i did the footage looked good. Both on the waveform and to my eyes.

Since then i have done a third shoot, this time not me shooting ( yay i get to learn from someone!).

The cameraman said he used 75% and backed off a bit (again im assuming he was talking skin tones for the ref point). This was on an hvx,

I put the footage in fcp and the skin tones were fairly good, but the level for many shots was over 100.

SO now im confused.. again.

Do I either try and expose for skin tones, or screw skin tones, and just make sure the whole scene is under 100 (using a program like dvrack) or do i come here and ask questions.

Seems like both.

I know im rambling but. i know this...


Set zebra for 70% and have it appear just into the highlights on the face (as mentioned by Tom).

Assuming i do this correctly the shot itll be good exposure.

But what if there may be background elements that are 100, or 110?!

In this instance i guess i either

a) put up a flag if i can or move a light.
or b) fix it in post with a broadcast legalizer do clamp the whole thing


The funny thing is before i knew about zebra i was getting better exposure overall, but im sure it wouldnt have been as consistent, and i believe after getting burned once, im a bit apprehensive
Now, if i can just get this right!

B.Sundry