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EX1 zebra advise needed! Stage show exposure problems

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Russell Robertson
EX1 zebra advise needed! Stage show exposure problems
on Aug 4, 2010 at 5:24:23 pm

Hello,

I’m fairly new to the EX1 having shot just a few stage performances since getting a pair. I’m having a difficult time getting good exposures of the actors because of a dam follow spot light that refuses to relent! So that’s the scenario I have to work with – a hot spot on an actor or two, and standard lighting for the rest of the stage.

It seems that I’m blowing out most of my footage where the spot light is on the subject – I suspect I’m not using the zebras properly. I’ll make some test footage this week during a dress rehearsal, but wanted to solicit any suggestions, comments or tips from the forum on how some of you shoot stage shows.

Ex. What zebra settings do you use, and what do you shoot for? (this is my first camera with variable zebra presets) Shoot to have no zebra patterns at all? Just a hint of the zebra pattern on the face of the subject?

Any Picture Profile suggestions for a stage show?

Thanks in advance for any comments, suggestions or advice.

RR


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Don Greening
Re: EX1 zebra advise needed! Stage show exposure problems
on Aug 4, 2010 at 6:31:58 pm

Well you'll definitely have to expose for the spot lit performer because that's what everyone will be looking at. Here's what you can do to make your life a little easier:

  • Use manual iris (obviously)
  • Set one zebra to 100% and the other to 80%
  • Look for the 80% to paint facial highlights such as forehead and cheekbones ONLY.
  • 100% zebras means those portions of the picture will be blown out depending on gamma selection.
  • Keep your hand glued to the iris ring so you can instantly compensate for sudden exposure changes.

Create a picture profile and call it stage or something similar. TUrn off AUTO KNEE because it doesn't work very well. Set your man. knee to 80 or 85%. this will give you more exposure latitude by compressing the highlights somewhat. Now you'll notice that it takes longer for the zebra bars to appear for the same amount of exposure. Go to the link below and watch the video tutorial that's 2nd from the top. By using certain gamma settings you can get more detail from the blacks, thereby pulling some of the other actors from the shadows a bit better.

http://www.xdcam-user.com/?page_id=13

- Don

Don Greening
Reeltime Videoworks
http://www.reeltimevideoworks.com


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Daniel Startek
Re: EX1 zebra advise needed! Stage show exposure problems
on Aug 5, 2010 at 2:53:21 pm

I used to use zebra only because that was all there was back in the Betacam days but now I also use the histogram display. Use both (histogram for balanced exposure) and zebra for peaks with zebra 2 set to 100% to prevent white clipping.



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Russell Robertson
Re: EX1 zebra advise needed! Stage show exposure problems
on Aug 5, 2010 at 4:24:35 pm

Don, Daniel,

Sincere thanks for all your help. I’ll be taking some test footage this evening and will incorporate your suggestions. Don, the link was very insightful – I printed out your bullet points and will bring them with me.

Just one elementary question. As noted previously, this is the first camera I’m using that has 2x different zebra settings. So if I set one to 80% (facial highlights) and the other to 100%, exactly how should I work the iris to control? Open/close until there is just a hint of a zebra on the 80% scale? (and stay away from anything in the 100% area)

Many thanks again – between re-reading the manual for the umpteenth time, viewing the camera usage DVD, your help here and test footage this evening, I should finally get some top quality exposures from the camera.

RR



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Craig Seeman
Re: EX1 zebra advise needed! Stage show exposure problems
on Aug 5, 2010 at 4:39:50 pm

Keep in mind Zebra settings and your response is a judgement call.

Sometimes you have to let the highlights blowout to get good exposure on the subject in an uncontrolled lighting situation.

Note that the white actually clips at 109%, not 100% which is where Zebra 2 triggers.
Also note that Zebra 1 is listed as ±10%.

These how the clipping and gamma are handled is where the Picture Profile settings become important.
If you're going to do post grading you might want to preserve those highlights knowing you might be able to bring up the mids within reason.



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Don Greening
Re: EX1 zebra advise needed! Stage show exposure problems
on Aug 5, 2010 at 7:11:31 pm

[Craig Seeman] "Note that the white actually clips at 109%, not 100% which is where Zebra 2 triggers."

Cinegammas 1, 3 and 4 are the only gamma curves that record up to 109% and then only if your picture gain is set to 0 (zero). All the rest will clip at 100% because they're the ones recommended for broadcast safe recording.

- Don

Don Greening
Reeltime Videoworks
http://www.reeltimevideoworks.com


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Craig Seeman
Re: EX1 zebra advise needed! Stage show exposure problems
on Aug 5, 2010 at 7:22:22 pm

Only CineGama 2 is limited. All the STD settings can go to 109% as well.





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Don Greening
Re: EX1 zebra advise needed! Stage show exposure problems
on Aug 5, 2010 at 7:42:44 pm

Well not according to Alister Chapman. So I guess one of these two people are wrong.

http://www.xdcam-user.com/?page_id=13

- Don

Don Greening
Reeltime Videoworks
http://www.reeltimevideoworks.com


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Craig Seeman
Re: EX1 zebra advise needed! Stage show exposure problems
on Aug 5, 2010 at 8:24:49 pm

It's from Alister's site
http://www.alisterchapman.com/?page_id=926



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Don Greening
Re: EX1 zebra advise needed! Stage show exposure problems
on Aug 5, 2010 at 8:43:59 pm

The text in that article is basically a carbon copy of what he says in the YouTube tutorial:

"Because of this Sony have allowed the peak white levels of Cinegammas 1, 3 and 4 to go up to 109%. If you are not going to grade your pictures then you should only use a standard gamma or cinegamma 2 which IS restricted to broadcast safe 100% ."

If all the gammas other than cinegamma 2 are allowed to go to 109% why didn't he say so? Instead he just singled out Cine 1, 3 and 4. Why does manual knee only work with the standard gammas if they too are allowed to go to 109%. Why does he talk about using the standard gammas and Cine 2 if you're not going to grade? Is it because all 4 are clipped to 100% ?.

Maybe I'm just not getting this but if you're correct and only Cine 2 is clipped to 100% then I find Alister's statements quite ambiguous. I don't care if I'm right or wrong but what I do care about is passing accurate and true information on to people that are asking the questions.

- don

Don Greening
Reeltime Videoworks
http://www.reeltimevideoworks.com


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Craig Seeman
Re: EX1 zebra advise needed! Stage show exposure problems
on Aug 5, 2010 at 10:01:33 pm

He doesn't go into as much detail about the Standard Gammas . . . at least not about their range although all the charts show the line going to 110 and when I've tested the Sttandard Gammas I can verify that's what they do when I shot a "hot" white object. You can see the response in the EX histogram as well. If you point the camera at a hot white object and go through the 4 standard and 4 cine gammas, only cine 2 hits a "wall."



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Don Greening
Re: EX1 zebra advise needed! Stage show exposure problems
on Aug 6, 2010 at 12:06:51 am

A couple of hours ago I did a similar test and found the same thing: only Cine 2 gets stopped at 100% while the other 7 go past. So, until I hear differently from Alister (left him a question to clarify) I'll now assume that all the gammas with the exception of Cine 2 can go to 109%.

Thanks for your help, Craig.

- Don

Don Greening
Reeltime Videoworks
http://www.reeltimevideoworks.com


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