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

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

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

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.

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

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.

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.

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

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...

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

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

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.

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.

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

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

Brendan,

You have a limited amount of contrast range to work with so if you expose for skin tones and other stuff blows out, you must re-frame or re-light the scene if possible to avoid that. You might be able to use a graduated ND on the front if it's a bright sky against horizon scenario. If you don't have skin tones, some say concrete should also be around 70%. Always best to under-expose a little cause you can recover some shadow detail in post, but blown highlights are gone and there's no getting them back.

-gb-

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

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.

I have a question as well...
I currently shoot with VX2100's and PD170's and had an issue while uding zebras at a wedding I shot 2 weeks ago.

The reception was midday to sunset and into the evening. The ballroom has glass pretty much going 3/4 of the way around it. So light is spilling in from everywhere.

I shot footage at 70 IRE for the entire day, and move around quite often handheld (mainly wide and medium shots, with some closeups), so sometimes I had light at my back (great scenerio), but most of the time I had light spilling in from all sides.

I made sure I was slightly seeing some small zebra, on faces I was shooting at 70IRE. However after I looked at much of the footage, most of the whites and any faces that had light shinning on their faces were blown out (not soft looking yellow gold like it should have).

My wife was manning a second camera on a stationary tripod, and mostly had light at her back, so her exposure was much better than mine with faces that had nice golden highlight for sun exposed faces.

So my question is this...
In my instance where I have no control over light spillage, ould it have been best for me to shoot at 100 IRE and adjust accordingly.
Or shoot at 70 IRE with ND filter on and make sure that that I don't have any zebra on faces.

I have a shoot this Saturday at the same venue, and would like to find a solution beforehand.

There is no "magic bullet" to all this, Brendan, it takes time to learn and experience to add a bit of voodoo to the mix to hopefully come out with a proper exposure.

Many news shooters use 100% (and often 90% zebras to keep from overexposing highlight areas, because they have been threatened with excommunication by some engineer at their station. This will keep them from burning out the hot sky, but may leave the face in the foreground underexposed, and usually you want the face properly exposed rather than the sky. Why you are choosing to use 90% zebras on a face I have no idea; this should lead to consistently overexposed flesh tones. Are you familiar with what you are viewing on the waveform display? However, let me say, if you set your zebras to 90%, and are getting consistently good results, who am I to argue?

"I put the footage in fcp and the skin tones were fairly good, but the level for many shots was over 100"
What was over 100%? A light in the background? A window to the outside? Was it something of value, or do just not want anything over 100%? Ever watch live music shows on tv, like "The Grammy Awards," or "The American Music Awards"? When those bright lights hit the camera lens, do you think they go over 100%? You bet they do, but they get clipped in the transmission, so there is no harm done. (I'm simplifying here a bit) So if you have a window in the background that is over 100%, but you like the way the picture looks, go ahead and shoot it, because you camera will clip it to an acceptable level, but you will lose the detail in that area, just as you see in your monitor. A waveform monitor is great, but if you spend all your time fiddling with the waveform and an outboard video monitor, you are not going to be getting much shooting done. This may be OK if you are shooting your movie, and you want everything as close to perfect as possible, but if you are under time constraints, your will be in the deep muddy.

You need to identify contrast problems before you even turn on the camera. For instance, I am writing this in my studio on my Cinema display monitor, in a room I keep at low light levels for my post production work. (Not dark, but dim light) If I wanted to shoot my monitor on camera, as well as the background wall, I need to have a reasonable range of contrast between foreground and background. I can identify a potential problem by using my eyes and squinting at the scene. By squinting, I lower the range of contrast to something closer to what the camera sees, and what I discover by squinting, is that the monitor looks great, but my background wall is almost black, and there is very little detail. This indicates a problem. Now reverse the situation.

You are outside shooting a stand-up piece with an on-camera host. She wants to stand facing the camera with her back to the sun (good), but in a position where you will see hot sky behind her. You view her and the sky, and when you squint, the sky cools down nicely, but her face goes black. Problem. You either need to add fill to her face, or cool off the sky, or move to another location. Or, you say "to hell with the sky" and expose for her face. If you have your zebras set to 100%, you will pull down the exposure until you would have only a hint of zebras in the sky, but I promise you, now her face will be underexposed.

The point is, you can identify the problem areas by squinting; you don't need a camera or a waveform to tell you that you have a problem. Don't take my word for it, just give it a try. This is a combination of learning and experience. Takes time. And continue reading and researching all you can find. Good luck.

Wayne Orr, SOC

In my instance where I have no control over light spillage, ould it have been best for me to shoot at 100 IRE and adjust accordingly.
Or shoot at 70 IRE with ND filter on and make sure that that I don't have any zebra on faces.

Michael, the posts above this one talk about this quite well. IRE is just a measurement tool. Exposure is a tougher question. In the situation you describe, contrast can have a lot of play in how you exposed the shot. A normally exposed face up against a 100IRE+ background just won't look the same as it does against a 40IRE level background. Again, 100 IRE just means that is where the video looses all detail, 110 IRE looks exactly the same as 100 IRE, and the same area at 95% is pretty much the same - way over-exposed. If your faces don't have any detail when their skin tone levels are just under 70 IRE, you might be having another type of problem.

t