zebras

goodtimej wrote on 12/17/2008, 4:53 PM
I was hoping that some of you could give me your opinions on the correct way to use zebras while I am shooting. Of course not the animal, but the stripes that help to let you know when a scene you are shooting is overexposed. I have searched this board and the web for a good explanation and had no luck.
I am shooting with the HDR-FX1 and the zebra level is adjustable. What do you all set your zebras at while shooting? thanks

Comments

craftech wrote on 12/17/2008, 5:10 PM
For stage productions they are useless. That's what I shoot. If you use them under stage lighting, the video will come out too dark every time.

John
rs170a wrote on 12/17/2008, 5:54 PM
Deliberately under-expose in well lit conditions? is an excellent thread that deals with this issue and gives you a lot of suggestions.

Mike
johnmeyer wrote on 12/17/2008, 8:00 PM
John,

I'm doing my annual Nutcracker on Sunday. No zebras for stage productions?? OK, I've got to ask, how do you get correct exposure? Just by looking at the LCD? By eye on an external calibrated monitor? Or do you have scopes?

For me, I've really come to rely on the zebras, although I too have found that I sometimes end up with footage that needs a little boost with Color Curves in order to get the right balance. I use 100 or 100+. Obviously using something like 70 makes no sense when dealing with spotlights, etc.

Before I used zebras, I would often get some pretty ugly burn out that I didn't spot at all, or just not quickly enough (this goes back 15-20 years ago with lesser equipment).

So, if you have a moment, please let me know. You are "the stage guy," and know this stuff cold.
Steve Mann wrote on 12/17/2008, 10:03 PM
"For stage productions they are useless. That's what I shoot. If you use them under stage lighting, the video will come out too dark every time."

Then you may be using zebras wrong. I'm with John here - without a scope, Zebras are your ONLY reliable exposure indicator.

I shoot stage performances with a pair of Sony Z1's. Set the zebras to 100% and manually stay on the iris through lighting changes to just make the zebras disappear.

Grazie wrote on 12/17/2008, 10:41 PM
I don't do stage events ( [i]"Oh yes you do! . ." "Oh no I don't . . ") - but with a lock-off, does anybody employ a Grad-ND to knock down the upper lights?

Hey, wouldn't it be great if we had a type of organic ND that went to the areas we wanted, and just kinda centered/focused on them, for "special" treatment?

Grazie
ushere wrote on 12/17/2008, 11:21 PM
grazie, you been at that funny stuff again?

ah hell, the grads paisley again....
Grazie wrote on 12/17/2008, 11:23 PM
lol . . .
Jay Gladwell wrote on 12/18/2008, 5:45 AM

For stage productions they are useless. That's what I shoot. If you use them under stage lighting, the video will come out too dark every time.

John, based on my experience with stage productions, I'm curious as to why you say that.

Would you, please, elaborate?

EDIT:

Here is a frame grab from a recent shoot. My zebra is set at 95%. I realize much is subjective, but does this look too dark?

pic


craftech wrote on 12/18/2008, 6:59 AM
For stage work I use a well calibrated external CRT monitor and adjust the exposure visually. Works every time. If you are dealing with professional lighting the zebras may work depending upon the production and size of the cast, but anyone who shoots productions in schools for example has to deal with stage lighting that has been subjected to budget cuts and also kids who don't know what they are doing. If there is a large cast many of the actors are in the "dark spots" - even the principals. The IRE on an actor can change as much as 10 - 20 IRE as they cross from one place to another. Sometimes they use double spots that often blow out the faces. The zebras are fooled too often.
I have the zebras on just to keep reminding myself of how unreliable they are. When I have the correct visual exposure (proven in post) the stripes are often visible in the brightest spots.

It sometimes works if you concentrate the zebras on the faces and set the zebras to 70 instead of what the camera's zebras think is white (leaving a little bit of zebra on the face). I have done this and it does work, but it is a PITA. Yet some cameras won't even let you do that. Some won't go lower than 80. Of course some actors have dark skin, so you have to expose on a nearby white actor and tweak the exposure. All time consuming and guess work.

It is much easier to calibrate a CRT monitor (provided you have a place to mount it) and do it visually (looking at the overall image on the screen. If you know your monitor is right, it will look the same in post. I do much less color correcting in post since I gave up zebras. I always use the tungsten setting for the white balance combined with a slight custom preset level change that I experimented with until I liked the results. Most good cameras have something similar. Sony calls it Control Panel and a CP appears on the screen when you turn it on. You can shift the white balance and levels and red to blue bias, etc. But mainly, I found that manual white balance is a waste of time because of all the gels on the lights and that tungsten works the best. As I said, I used to color correct every scene at one time, now I don't. I also stopped trying to compensate for directors who think no light is good, then expect great video later. I leave it so that it looks dark. If you can't see every actors face, I remind them that that is how it looked to the audience and I "captured the moment for you".

Note: I attend the rehearsals so I know my shots ahead of time. This works to a degree, but don't be surprised if the director changes things last minute and doesn't tell you. Attending the rehearsals will also allow you to show the director how it will look later. Many times the director will change the lighting because they can see for themselves how awful it will look. Remind them that the video is the "permanent record" of their artistry that people will remember forever and not the no-light mole stuff or the red on red on red vomit scene.

John: For the Nutcracker, if you are shooting only one single show, you would have better results with a second camera person for the party scene. For "Snow " and all of Act II, one camera will do just fine.

John


Jeff9329 wrote on 12/18/2008, 8:26 AM
What do you all set your zebras at while shooting? thanks

90% for me, but everybody does it differently. The zebras are just tipping you off that you may need to lower your exposure if an area is about to overexpose that is important, like someones face.

Does the FX-1 have an adjustable knee curve? If so, you should experiment with that. It keeps highlights from being blown.
plasmavideo wrote on 12/18/2008, 8:39 AM
First of all - John, good luck with your Nutcracker shoot Sunday. Hope you don't have a kid rolling around on the floor counting backwards from 100 like I did :-)

Two of my cameras have a scene setting called Spotlight mode. It's been very effective on stage shots keeping faces from blowing out. That had always been a problem for me before.

For indoor shots I usually use the zebra at 100 and kinda judge the rest by eye in the LCD monitor. I will say that if there is a high contrast shot, you can easily get fooled by the zebra and underexpose, making the blacks looked crushed.

Outdoors with less contrast, i typically use the 70% setting and make sure that zebra appears all of the time on whatever I'm focused on. Those shots seem to be better balanced than when I've relied on 100% zebra. My theory is that you can always correct underexposure in post, but once you've clipped the whites, you are hosed.

Tom
johnmeyer wrote on 12/18/2008, 9:08 AM
John: For the Nutcracker, if you are shooting only one single show, you would have better results with a second camera person for the party scene. For "Snow " and all of Act II, one camera will do just fine.I have shot the Nutcracker every year since 1981, when I shot my wife's company, directed by Jurgen Schneider, the ballet master from ABT. During all these years, I have sometimes shot every performance, so I know this ballet by heart (all Petipa choreography).

The two scenes you mention is where I always re-check the settings on my main camera, i.e., I do exactly what you suggest and just use the wide shot which means I zoom in and check focus on my main camera and make sure the shutter speed, gain, aperture, WB, and other settings haven't been bumped or set wrong. I always try to check during a shoot, so if I have made an error, I only lose part of the performance, not all of it.

I suspected you might be using a monitor, and I can see how that would be the best way to go. Like you, I have to deal with lighting that hasn't in any way been adjusted with video in mind, so I have to make some very quick decisions on what to expose for. Since I know that burned-out highlights are gone forever, but shadows can sometimes be rescued, I do tend to err on the dark side.

As for settings, I already mentioned the 100% zebra. 70% will, of course, give you MORE zebras, but is useful to get correct skin and face tones. Since I'm dealing with two (and this year three) cameras, and it's just me, I have to have some decent auto settings for the unattended camera. As already suggested, I use the Spotlight mode. It really works quite well, and appears that it may work even better on this SR12 I'm borrowing.

In addition, on the FX1, I use the PPV menus to set up a series of six AE- menus. This is the function that takes the auto exposure and then adds or subtracts from that. I then use this on the FX1 as the override to my auto+spotlight exposure. Using pure manual exposure is absolutely out of the question given how quickly and often the lighting changes, and the impossibility of memorizing a million presets. Plus, the FX1 doesn't have exposure preset (or focus preset) capability. The nice thing about this arrangement is I either forget to re-adjust exposure, or simply react slowly, the AE will get me at least part way there, so I don't completely lose the scene. Then, usually within a few seconds, I slowly crank up/down the AE+- presets in the PPV menus until I like the exposure.

The only thing I DON'T like about my approach is that I have no control over gain, and I sometimes suspect that the FX1 turns that up at a point prior to where I would use it. However, generally the footage is quite noise free, especially compared to the SR12. I must say that my brief exposure to the SR12 doesn't really make me want to invest in AVCHD or CMOS (although I guess I may not have a choice on the CMOS side). Very noisy video from this camera.

Based on your input, I may shoot this year's production a little hotter than usual. That said, the still shot posted earlier in this thread by Jay looks awfully good to me. Not many stage videos show the level of detail in the white skirt shown in the foreground (and even at that dark exposure, the sleeve on the male dancer in the background is blown out). And, if you've shot the Nutcracker, try getting the snow queen exposed correctly (typical costume is pure white, lit by a follow spot).




craftech wrote on 12/18/2008, 10:17 AM
That said, the still shot posted earlier in this thread by Jay looks awfully good to me. Not many stage videos show the level of detail in the white skirt shown in the foreground
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He probably shot it with his Ex1. I still haven't used that camera for a stage production yet. I have such good luck with the VX2000 I hate to mess with conversions, etc. I will probably try it out for the Spring Musical I always shoot in March. There are so many dress rehearsals and shows it will allow me to "play".

John
Steve Mann wrote on 12/18/2008, 9:26 PM
"... making the blacks looked crushed."

If an actor is in a dark area on the stage, that's probably what the director wants. No director or actor has *ever* complained to me about someone in the shadows while another character is in a spotlight. Why spend so much effort trying to "correct" a look that the director wanted? On the other hand, blown out whites to see the character in the shadows looks much worse, even amateurish.

On the Zebras - they do not lie. If you set the Zebras to 100-IRE, then you will see Zebra stripes in anything between 95-105-IRE. If you set the Zebras to 70-IRE, then you will see Zebras in areas lit to 65- to 75-IRE. BUT NOT ABOVE 75-IRE. (See page 31 of the Z1 Operating Instructions).

I'll repeat for clarification - Set your Zebras to 70-IRE and blown-out, overexposed areas at or above 100-IRE *WILL NOT* have Zebras in the viewfinder.
johnmeyer wrote on 12/18/2008, 9:54 PM
Set your Zebras to 70-IRE and blown-out, overexposed areas at or above 100-IRE *WILL NOT* have Zebras in the viewfinder. Very useful. I did not know that.
craftech wrote on 12/20/2008, 6:29 PM
If an actor is in a dark area on the stage, that's probably what the director wants.
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I can tell you without hesitation that is the exception rather than the norm. How do I know this? Because I make it a habit of attending all the rehearsals and I can see and hear what the directors are frustrated with. The lighting people are most often unable to light the stage evenly - especially in schools where they are subjected to infrastructure deterioration and budget cuts or rails that cannot be lowered to aim the lamps and on and on. Hot spots, dark areas, all major problems in many "non-Broadway" stage productions. Most videographers that I know do not attend every rehearsal throughout the process, so they would not know what the director is thinking or changing their mind or discussing endlessly with everyone under the sun.

John
musicvid10 wrote on 12/20/2008, 6:58 PM
My goodness. Honor the director's vision wherever practical, deal with the light designer's "interpretation," show up early and take notes religiously at dress rehearsal and never expect anything to be the same on opening night, know your viewfinder by heart, set the brights intuitively (never use auto-iris), and live with the results.

Anything more complicated than that is just masochistic, IOW nonsense!

Zebras are a good starting point, and no substitute for experience in stage productions. JMO